| 1. |
- Adolfsson, Karin H., et al.
(författare)
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In Vivo Versus In Vitro Degradation of a 3D Printed Resorbable Device for Ligation of Vascular Tissue in Horses
- 2021
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 21:10
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Tidskriftsartikel (refereegranskat)abstract
- A resorbable 3D printed polydioxanone (PDO) device is manufactured to facilitate ligation of vascular tissue during surgery. The device must provide sufficient mechanical performance throughout the healing period. Therefore, degradation and mechanical performance of the device are investigated as a function of in vivo and in vitro aging. During aging the PDO device released cyclic and linear water-soluble products. In vivo aging resulted in higher relative number of linear oligomers in comparison to in vitro aging. A major loss of mechanical performance is observed after only 10 days in vivo and the Young’s modulus (E) and tensile strength at break (σb) decreased by 28% and 54%, respectively. This is in contrast to in vitro aging, where no loss of mechanical properties is observed during the same period. The in vivo aged devices exhibit clear holes in the matrices after 28 days, while apparent cracks are observed first after 140 days in vitro. These results highlight the sensitivity of the degradation process of resorbable devices with regards to the interactions of the device with the surrounding environment (tissues) and demonstrate the importance of in vivo testing as compliment to in vitro testing before clinical use of devices.
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| 2. |
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| 3. |
- Aljadi, Zenib, et al.
(författare)
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Layer-by-Layer Cellulose Nanofibrils : A New Coating Strategy for Development and Characterization of Tumor Spheroids as a Model for In Vitro Anticancer Drug Screening
- 2022
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 22:10
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional multicellular spheroids (MCSs) are complex structure of cellular aggregates and cell-to-matrix interaction that emulates the in-vivo microenvironment. This research field has grown to develop and improve spheroid generation techniques. Here, we present a new platform for spheroid generation using Layer-by-Layer (LbL) technology. Layer-by-Layer (LbL) containing cellulose nanofibrils (CNF) assemble on a standard 96 well plate. Various bi-layer numbers, multiple cell seeding concentration, and two tumor cell lines (HEK 293 T, HCT 116) are utilized to generate and characterize spheroids. The number and proliferation of generated spheroids, the viability, and the response to the anti-cancer drug are examined. The spheroids are formed and proliferated on the LbL-CNF coated wells with no significant difference in connection to the number of LbL-CNF bi-layers; however, the number of formed spheroids correlates positively with the cell seeding concentration (122 ± 17) and (42 ± 8) for HCT 116 and HEK 293T respectively at 700 cells ml−1. The spheroids proliferate progressively up to (309, 663) µm of HCT 116 and HEK 293T respectively on 5 bi-layers coated wells with maintaining viability. The (HCT 116) spheroids react to the anti-cancer drug. We demonstrate a new (LbL-CNF) coating strategy for spheroids generation, with high performance and efficiency to test anti-cancer drugs.
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| 4. |
- Asif, Sana, M.D, PhD student, et al.
(författare)
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Validation of an MPC polymer coating to attenuate surface- induced cross-talk between the complement and coagulation systems in whole blood in in vitro and in vivo models
- 2019
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Ingår i: Macromolecular Bioscience. - : Wiley-VCH Verlagsgesellschaft. - 1616-5187 .- 1616-5195. ; 19:5
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Tidskriftsartikel (refereegranskat)abstract
- Artificial surfaces that come into contact with blood induce an immediate activation of the cascade systems of the blood, leading to a thrombotic and/or inflammatory response that can eventually cause damage to the biomaterial or the patient, or to both. Heparin coating has been used to improve hemocompatibility, and another approach is 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer coatings. Here, the aim is to evaluate the hemocompatibility of MPC polymer coating by studying the interactions with coagulation and complement systems using human blood in vitro model and pig in vivo model. The stability of the coatings is investigated in vitro and MPC polymer-coated catheters are tested in vivo by insertion into the external jugular vein of pigs to monitor the catheters' antithrombotic properties. There is no significant activation of platelets or of the coagulation and complement systems in the MPC polymer-coated one, which was superior in hemocompatibility to non-coated matrix surfaces. The protective effect of the MPC polymer coat does not decline after incubation in human plasma for up to 2 weeks. With MPC polymer-coated catheters, it is possible to easily draw blood from pig for 4 days in contrast to the case for non-coated catheters, in which substantial clotting is seen.
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| 5. |
- Basu, Alex, et al.
(författare)
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Hemocompatibility of Ca2+-Crosslinked Nanocellulose Hydrogels : Toward Efficient Management of Hemostasis
- 2017
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 17:11
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Tidskriftsartikel (refereegranskat)abstract
- The present work investigates Ca2+-crosslinked nanofibrillated cellulose hydrogels as potential hemostatic wound dressings by studying core interactions between the materials and a central component of wounds and wound healing—the blood. Hydrogels of wood-derived anionic nanofibrillated cellulose (NFC) and NFC hydrogels that incorporate kaolin or collagen are studied in an in vitro whole blood model and with platelet-free plasma assays. The evaluation of thrombin and factor XIIa formation, platelet reduction, and the release of activated complement system proteins, shows that the NFC hydrogel efficiently triggered blood coagulation, with a rapid onset of clot formation, while displaying basal complement system activation. By using the NFC hydrogel as a carrier of kaolin, the onset of hemostasis is further boosted, while the NFC hydrogel containing collagen exhibits blood activating properties comparable to the anionic NFC hydrogel. The herein studied NFC hydrogels demonstrate great potential for being part of advanced wound healing dressings that can be tuned to target certain wounds (e.g., strongly hemorrhaging ones) or specific phases of the wound healing process for optimal wound management.
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| 6. |
- Berglin, Mattias, 1970, et al.
(författare)
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Flexible and Biocompatible Antifouling Polyurethane Surfaces Incorporating Tethered Antimicrobial Peptides through Click Reactions
- 2024
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Ingår i: Macromolecular Bioscience. - : John Wiley and Sons Inc. - 1616-5187 .- 1616-5195. ; 24:4
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Tidskriftsartikel (refereegranskat)abstract
- Efficient, simple antibacterial materials to combat implant-associated infections are much in demand. Herein, the development of polyurethanes, both cross-linked thermoset and flexible and versatile thermoplastic, suitable for “click on demand” attachment of antibacterial compounds enabled via incorporation of an alkyne-containing diol monomer in the polymer backbone, is described. By employing different polyolic polytetrahydrofurans, isocyanates, and chain extenders, a robust and flexible material comparable to commercial thermoplastic polyurethane is prepared. A series of short synthetic antimicrobial peptides are designed, synthesized, and covalently attached in a single coupling step to generate a homogenous coating. The lead material is shown to be biocompatible and does not display any toxicity against either mouse fibroblasts or reconstructed human epidermis according to ISO and OECD guidelines. The repelling performance of the peptide-coated materials is illustrated against colonization and biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis on coated plastic films and finally, on coated commercial central venous catheters employing LIVE/DEAD staining, confocal laser scanning microscopy, and bacterial counts. This study presents the successful development of a versatile and scalable polyurethane with the potential for use in the medical field to reduce the impact of bacterial biofilms.
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| 7. |
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| 8. |
- Berillo, Dmitriy, et al.
(författare)
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Oxidized Dextran as Crosslinker for Chitosan Cryogel Scaffolds and Formation of Polyelectrolyte Complexes between Chitosan and Gelatin.
- 2012
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 12:8, s. 1090-1099
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Tidskriftsartikel (refereegranskat)abstract
- Macroporous scaffolds composed of chitosan and using oxidized dextran as a crosslinker are produced through cryogelation. Introducing gelatin as a third component into the structure results in the formation of mesopores in the pore walls, which are not seen if gelatin is excluded. The mesoporous structure is explained by the formation of polyelectrolyte complexes between chitosan and gelatin before crosslinking takes place. The scaffolds exhibit highly elastic properties withstanding compressions up to 60%. The in vitro biocompatibility of the cryogels is evaluated using fibroblasts from a mouse cell line (L929) and it is seen that the cells adhere and proliferate on the scaffolds. The mesoporous structure seems to have a positive effect on proliferation.
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| 9. |
- Bhat, Sumrita, et al.
(författare)
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In Vitro Neo-Cartilage Formation on a Three-Dimensional Composite Polymeric Cryogel Matrix
- 2013
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 13:7, s. 827-837
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Tidskriftsartikel (refereegranskat)abstract
- Limited blood supply and the avascular nature of articular cartilage restricts its self repair capacity, frequently leading to osteoarthritis. This work focuses on scaffolds for tissue repair from natural polymers, for example gelatin, chitosan, and agarose in the form of composite. A novel way of fabrication, known as cryogelation, is presented, in which matrices are synthesized at sub-zero temperature. Cell seeded scaffolds incubated under appropriate conditions result in the accumulation of matrix components on the surface of the gel in the form of neo-cartilage. Neo-cartilage exhibits similarity to native cartilage with respect to its physical, mechanical and biochemical properties. Based on the similarities of neo-cartilage to the native cartilage, it can provide a new approach for the treatment of localised joint injuries.
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| 10. |
- Biscari, Giuseppina, et al.
(författare)
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Antibacterial Broad-Spectrum Dendritic/Gellan Gum Hybrid Hydrogels with Rapid Shape-Forming and Self-Healing for Wound Healing Application
- 2023
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195.
-
Tidskriftsartikel (refereegranskat)abstract
- Treating wound infections is a difficult task ever since pathogenic bacteria started to develop resistance to common antibiotics. The present study develops hybrid hydrogels based on the formation of a polyelectrolyte complex between the anionic charges of dopamine-functionalized Gellan Gum (GG-DA) and the cationic moieties of the TMP-G2-alanine dendrimer. The hydrogels thus obtained can be doubly crosslinked with CaCl2, obtaining solid hydrogels. Or, by oxidizing dopamine to GG-DA, possibly causing further interactions such as Schiff Base and Michael addition to take place, hydrogels called injectables can be obtained. The latter have shear-thinning and self-healing properties (efficiency up to 100%). Human dermal fibroblasts (HDF), human epidermal keratinocytes (HaCaT), and mouse monocyte cells (RAW 264.7), after incubation with hydrogels, in most cases show cell viability up to 100%. Hydrogels exhibit adhesive behavior on various substrates, including porcine skin. At the same time, the dendrimer serves to crosslink the hydrogels and endows them with excellent broad-spectrum microbial eradication activity within four hours, evaluated using Staphylococcus aureus 2569 and Escherichia coli 178. Using the same GG-DA/TMP-G2-alanine ratios hybrid hydrogels with tunable properties and potential for wound dressing applications can be produced.
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| 11. |
- Eslami, M., et al.
(författare)
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A One Step Procedure toward Conductive Suspensions of Liposome-Polyaniline Complexes
- 2020
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 20:11
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Tidskriftsartikel (refereegranskat)abstract
- Interaction of conjugated polymers with liposomes is an attractive approach that benefits from both systems’ characteristics such as electroactivity and enhanced interaction with cells. Conjugated polymer-liposome complexes have been investigated for bioimaging, drug delivery, and photothermal therapy. Their fabrication has largely been achieved by multistep procedures that require first the synthesis and processing of the conjugated polymer. Here, a new one step fabrication approach is reported based on in situ polymerization of a conjugated monomer precursor around liposomes. Polyaniline (PANI) doped with phytic acid is synthesized via oxidative polymerization in the presence of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) vesicles to produce a conductive aqueous suspension of Liposome-PANI complexes. PANI interacts with liposomes without disrupting the bilayer as shown using differential scanning calorimetry and fluorescence quenching studies of the hydrophobic Nile red probe. The electronic conductivity of the Liposome-PANI complexes, which stems from the doped PANI accessible on the liposome surface, is confirmed using conductive atomic force microscopy and electrochemical impedance spectroscopy. Further, short-term in vitro cell studies show that the complexes colocalize with the cell membrane without reducing cell proliferation. This study presents a novel fabrication route to conductive suspensions of conjugated polymer-liposome complexes suitable for potential applications at the biointerface.
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| 12. |
- Finne Wistrand, Anna, et al.
(författare)
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Resorbable Scaffolds from Three Different Techniques : Electrospun Fabrics, Salt-Leaching Porous Films, and Smooth Flat Surfaces
- 2008
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 8:10, s. 951-959
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Tidskriftsartikel (refereegranskat)abstract
- Nanofibrous scaffolds of poly[(L-lactide)-co-(1,5-dioxepan-2-one)] generated by electrospinning have been compared with porous films obtained by solvent cast/salt leaching and homogeneous films. A comparison between the fibrous materials and the homogeneous solvent-cast films revelead that the surface of the nanofibers was more hydrophobic and that the nanofibers were degraded more rapidly in the presence of proteinase. It was obvious that the strain-to-break was reduced by the nanofiber formation, it decreased from 370% to 130% independent of fiber diameter. These values were however considerably higher than the strain-to-break of the solvent-cast/salt leaching scaffold. In addition, the nanofibrous material accelerated the adhesion and growth of the mesenchymal stem cell compared to the smooth material.
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| 13. |
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| 14. |
- He, Min, et al.
(författare)
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Super-Anticoagulant Heparin-Mimicking Hydrogel Thin Film Attached Substrate Surfaces to Improve Hemocompatibility
- 2017
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Ingår i: Macromolecular Bioscience. - : WILEY-V C H VERLAG GMBH. - 1616-5187 .- 1616-5195. ; 17:2
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Tidskriftsartikel (refereegranskat)abstract
- In this study, heparin-mimicking hydrogel thin films are covalently attached onto poly(ether sulfone) membrane surfaces to improve anticoagulant property. The hydrogel films display honeycomb-like porous structure with well controlled thickness and show long-term stability. After immobilizing the hydrogel films, the membranes show excellent anticoagulant property confirmed by the activated partial thromboplastin time values exceeding 600 s. Meanwhile, the thrombin time values increase from 20 to 61 s as the sodium allysulfonate proportions increase from 0 to 80 mol%. In vitro investigations of protein adsorption and blood-related complement activation also confirm that the membranes exhibit super-anticoagulant property. Furthermore, gentamycin sulfate is loaded into the hydrogel films, and the released drug shows significant inhibition toward E. coli bacteria. It is believed that the surface attached heparin-mimicking hydrogel thin films may show high potential for the applications in various biological fields, such as blood contacting materials and drug loading materials.
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| 15. |
- Herland, Anna, et al.
(författare)
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Macromolecular Bioelectronics
- 2020
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 20:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 16. |
- Houben, Annemie, et al.
(författare)
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Indirect Solid Freeform Fabrication of an Initiator-Free Photocrosslinkable Hydrogel Precursor for the Creation of Porous Scaffolds
- 2016
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 16:12, s. 1883-1894
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, a photopolymerized urethane-based poly(ethylene glycol) hydrogel is applied as a porous scaffold material using indirect solid freeform fabrication (SFF). This approach combines the benefits of SFF with a large freedom in material selection and applicable concentration ranges. A sacrificial 3D poly(epsilon-caprolactone) structure is generated using fused deposition modeling and used as template to produce hydrogel scaffolds. By changing the template plotting parameters, the scaffold channel sizes vary from 280 to 360 m, and the strut diameters from 340 to 400 m. This enables the production of scaffolds with tunable mechanical properties, characterized by an average hardness ranging from 9 to 43 N and from 1 to 6 N for dry and hydrated scaffolds, respectively. Experiments using mouse calvaria preosteoblasts indicate that a gelatin methacrylamide coating of the scaffolds results in an increased cell adhesion and proliferation with improved cell morphology.
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| 17. |
- Hruby, Martin, et al.
(författare)
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Thermoresponsive, Hydrolytically Degradable Polymer Micelles Intended for Radionuclide Delivery
- 2009
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 9:10, s. 1016-1027
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Tidskriftsartikel (refereegranskat)abstract
- Novel polymer micelles, prepared by self-assembling thermoresponsive poly(N-isopropylacrylamide)-graft-poly[N-(2-hydroxypropyl)methacrylamide] copolymers with hydrolytically degradable N-glycosylamine groups between the polymer blocks are proposed for delivery of diagnostic and therapeutic radionuclides into solid tumors. The micelles are formed by fast heating of an aqueous solution of the copolymer to 37 °C. They have a hydrodynamic diameter of 128 nm (measured using dynamic light scattering) and slowly degrade during incubation in aqueous buffer at pH = 7.4. Labeling with both 131I and 90Y proceeds with high yields (>85%). The unlabeled polymers are not cytotoxic for any of the tested murine and human cell lines.
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| 18. |
- Hua, Geng, et al.
(författare)
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Isocyanate-Free, UV-Crosslinked Poly(Hydroxyurethane) Networks: A Sustainable Approach toward Highly Functional Antibacterial Gels
- 2017
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Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195.
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Tidskriftsartikel (refereegranskat)abstract
- An increased sustainabile awarness has inspired the development of new polymeric networks in a remarkable way and this strive should be combined with environmentally concerned end-uses. Therefore, a UV-crosslinked polyhydroxyurethane film with antibacterial properties is developed. First, a hydroxyurethane precursor is synthesized using aminolysis condensation, circumventing the use of isocyanates. The films are subsequently crosslinked under solvent-free conditions through a UV-triggered thiol-ene mechanism. The reactions are monitored by 1H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy, and the networks have gel contents above 90%, and are transparent, hydrophilic, and highly flexible. Antibacterial properties are achieved by a controlled quaternization of the network's tertiary-amine and methylation of thiol-ether functionality, resulting in quaternary ammonium compounds (QACs) and sulfonium compounds. The antibacterial properties are evaluated against both Escherichia coli and Staphylococcus aureus using the agar plate diffusion and tube shaking methods. The QAC-loaded films exhibit outstanding bactericide properties (>99.9%) and the antibacterial mechanism is demonstrated to be a dual killing mechanism, i.e., diffusion killing and contact active killing.
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| 19. |
- Höglund, Anders, et al.
(författare)
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Assessing the Degradation Profile of Functional Aliphatic Polyesters with Precise Control of the Degradation Products
- 2012
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 12:2, s. 260-268
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Tidskriftsartikel (refereegranskat)abstract
- The pre-polymer poly(but-2-ene-1,4-diyl malonate) (PBM) and a series of PBM-based materials are shown to be degradable under physiological conditions in vitro and they are therefore presented as potential materials for biomedical applications. Four different PBM-based materials are synthesized: a PBM homopolymer, crosslinked PBM with and without spacer, and a triblock copolymer of PBM and PLLA with the PBM as an amorphous middle block. The polymers are subjected to hydrolytic degradation in phosphate-buffered saline at pH = 7.4 and 37 °C. The results show that all the PBM-based materials degrade without a rapid release of acidic degradation products or any substantial lowering of the pH that might jeopardize their biocompatibility.
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| 20. |
- Ivanov, Alexander, et al.
(författare)
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Binding of adenosine to pendant phenylboronate groups of thermoresponsive copolymer: a quantitative study
- 2005
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 5:8, s. 795-800
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Tidskriftsartikel (refereegranskat)abstract
- Binding of adenosine to the thermosensitive copolymer of N-isopropylacrylamide and 3-(acrylamido)aminophenylboronic acid (82:18, m ($) over bar (n)=47000 g center dot mol(-1)) was studied by equilibrium dialysis at 22 degrees C and 37 degrees C, in a 0.1 m glycine buffer containing 0.1 m NaCl at pH 9.2. The copolymer exhibited a the phase transition temperature (T-p) of 26.5 degrees C under the above conditions. At 22 degrees C the binding of adenosine to the water-soluble copolymer was well described by a Langmuir model, accounting for preferential ionisation of the boronate-nucleoside complexes and, therefore, restricted reactivity of the rest of boronates. At saturation, the copolymer contained 38% of its phenylboronic acid groups in the form of complexes, whereas the association constant was 1400 m(-1). At 37 degrees C no binding of adenosine to thermally precipitated copolymer was found, presumably owing to interaction of the phenylboronates with hydrophobic segments of polyNIPAM. At high loading of the copolymer by the reversibly bound adenosine the T (p) steeply increases with increasing fraction of the phenylboronate-adenosine complexes in the chains. The increase of the T-p observed above the saturating adenosine concentration (> 1 x 10(-3) m, 22 degrees C) very probably testifies to competition of the nucleoside with hydrophobic polyNIPAM segments for binding to the pendant phenylboronates.
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| 21. |
- Ivanov, Alexander E, et al.
(författare)
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Reversible Conformational Transitions of a Polymer Brush Containing Boronic Acid and its Interaction with Mucin Glycoprotein.
- 2011
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 11, s. 275-284
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Tidskriftsartikel (refereegranskat)abstract
- Reversible changes of the height of a polymer brush containing phenylboronic acid were studied. The polymer brush thickness underwent reversible changes of 0.5-1 nm, in response to the changes in composition of the contacting aqueous phase from deionized water to bicarbonate buffer and vice versa, apparently due to the conformational transition of the weak polyelectrolyte to the more extended electrically charged state. Adsorption of mucin glycoprotein to the polymer brush took place due to boronate/sugar interactions between the glycoprotein and the graft copolymer and resulted in further increase of the brush height by ca. 1.5 nm, as observed by means of spectral correlation spectroscopy and ellipsometry.
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| 22. |
- Ivinova, Olga, et al.
(författare)
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Influence of complexing polyanions on the thermostability of basic protiens.
- 2003
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 3:3-4, s. 210-215
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Tidskriftsartikel (refereegranskat)abstract
- Lysozyme (Lyz), chymotrypsinogen (Cht), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were used as model proteins capable of forming water-soluble polyelectrolyte complexes with linear synthetic polyanions. The complex formation with sodium poly(methacrylate) (PMA), sodium poly(acrylate) (PAA), sodium poly(anetholsulfonate) (PAS), and potassium poly(vinylsulfate) (PVS) markedly reduced the temperature of protein denaturation, Tmax, as determined by differential scanning calorimetry (DSC). The effect of sodium poly(styrenesulfonate) (PSS) on Lyz was so drastic that the protein melting peak was not observed at all during DSC measurements. The temperature shift, most pronounced for Lyz, increased upon substitution of the polyanions according to the following series: PMA < PVS < PAA < PAS < PSS. Decomposition of the complexes by addition of either sodium chloride or poly(N-ethyl-4-vinylpyridinium) cation completely restored the initial Tmax of the protein (except for PSS and PAS). The complex formation slightly affected the enzyme activity up to temperatures close to Tmax of the polyanion-protein complex. On further heating, the activity of the complex decreased steeply, whereas the free enzyme maintained a high activity. The data obtained strongly suggest that the protein-polyelectrolyte interactions in solution, while leaving the thermostability and activity of the proteins practically unaffected over a rather wide temperature range, result in the effective denaturation of proteins once a certain critical temperature is achieved. This finding appears to be crucial for further development of immobilized enzymes in biotechnology and essential for understanding mechanisms and principles of the functioning of proteins immobilized on charged matrices in vivo.
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| 23. |
- Kirsebom, Harald, et al.
(författare)
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Enzyme-Catalyzed Crosslinking in a Partly Frozen State: A New Way to Produce Supermacroporous Protein Structures.
- 2013
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 13:1, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- In this study a new way to produce supermacroporous protein structures was investigated. Enzyme-mediated crosslinking of gelatin or casein was performed in a partly frozen state, which yielded stable, protein-based cryogels. The reaction kinetics for the formation of cryogels were found to be fairly slow, most likely due to the low temperature (-12 °C) used or due to an increased viscosity owing to the cryo-concentration taking place. The produced cryogels were characterized with regards to their physical properties and in vitro degradation. Furthermore, cryogels produced from gelatin and casein were evaluated as potential scaffolds by fibroblast cultivation to confirm their in vitro biocompatibility. Gelatin- and casein-based scaffolds both supported cell proliferation and migration through the scaffold.
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| 24. |
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| 25. |
- Kuzimenkova, Marina, et al.
(författare)
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Boronate-containing copolymers: Polyelectrolyte properties and sugar-specific interaction with agarose gel
- 2006
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 6:2, s. 170-178
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Tidskriftsartikel (refereegranskat)abstract
- Copolymers of N-acryloyl-m-aminophenylboronic acid (NAAPBA) with acryamide (AA), N,N-dimethylacrylamide (DMAA), and N-isopropylacrylamide (NIPAM) were found to adsorb on cross-linked agarose gel (Sepharose CL-6B) in the pH range from 7.5-9.2, due to specific boronate-sugar interactions. The molar percentages of phenylboronic acid (PBA) groups in the boronate-containing copolymers (BCCs), as estimated by H-1 NMR spectroscopy, were 13, 10, and 16%, respectively, whereas the apparent ionization constants, the pK(a) values, of the copolymers were similar and equal to 9.0 +/- 0.2 at 20 degrees C. The copolymers adsorption capacities were in the range of 15-30 mg center dot ml(-1) gel (14-36 mu mol pendant PBA ml(-1) gel) at pH 9.2 and decreased with decreasing pH value. The interaction of monomeric NAAPBA with Sepharose CL-6B was characterized by an equilibrium association constant of 53 +/- 17 m(-1), the chromatographic capacity factor k ' = 1.8, and a total content of binding sites of 27 +/- 10 mu mol center dot ml(-1) gel at pH 9.2. The weak reversible binding of monomeric NAAPBA and almost irreversible binding of NAAPBA copolymers to the gel at pH 9.2 suggested a multivalent character of the copolymer adsorption. At pH 7.5, the maximal adsorption capacity was displayed by the AA-NAAPBA copolymer (45 mg center dot ml(-1) gel). All the BCCs could be completely desorbed from the gel by 0.1 m fructose in aqueous buffered media with pH values from 7.5-9.2. The strong adsorption of AA-NAAPBA on agarose gel probably relates to the conformation of the copolymer in aqueous solution and provides opportunities for biomedical applications of the copolymer under physiological conditions. Multivalent, weak-affinity adsorption of BCCs to the agarose gel seems to be a tentative model for the copolymers' binding to oligo- and polysaccharides of cell membranes and mucosal surfaces.
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| 26. |
- Kvick, Mathias, et al.
(författare)
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Cyclic Expansion/Compression of the Air-Liquid Interface as a Simple Method to Produce Silk Fibers.
- 2021
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembly of recombinant spider silk protein at air-liquid interfaces is used as a starting point to produce homogeneous fiber bundles. The film that is formed on a silk protein solution in a vertically placed syringe is subjected to repeated controlled extension and compression by an oscillating vertical motion. Thereby, a precise breakup of the film can be achieved, followed by transport and roll-up against the syringe wall prior to extraction. Advantages of the method are that it 1) is simple to use; 2) requires a small volume of protein solution (1 mL) at relatively low concentration (1 mg mL-1 ); 3) can be performed under sterile conditions; 4) does not require any use of coagulants; and 5) is compatible with the addition of viable cells during the process, which thereby are integrated uniformly throughout the fiber.
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| 27. |
- Källrot, Martina, et al.
(författare)
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Surface Functionalization of Porous Resorbable Scaffolds by Covalent Grafting
- 2008
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Ingår i: Biomaterials. - : Wiley. - 0142-9612 .- 1878-5905. ; 8:7, s. 645-654
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Tidskriftsartikel (refereegranskat)abstract
- Resorbable porous scaffold discs and solid films were prepared from poly[(1,5-dioxepan-2one)-co-(L-lactide)] and poly [(epsilon-caprolactone)-co-(L-lactide)]. The surfaces of the scaffolds were functionalized to increase their hydrophilicity. A total of 90 samples were prepared to cover all important combinations of experimental and material factors, and all experimental data were fitted by a partial least square model. As a result of grafting, the porous discs and solid films exhibited a tremendous increase in wettability. The functionalized discs were hygroscopic so that water was instantly absorbed and thoroughly wet the substrates.
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| 28. |
- Mathew, Aji P., et al.
(författare)
-
Biocompatible fibrous networks of cellulose nanofibres and collagen crosslinked using genipin : potential as artificial ligament/tendons
- 2013
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 13:3, s. 289-298
-
Tidskriftsartikel (refereegranskat)abstract
- Bio-based fibrous nanocomposites of cellulose nanofibres and non-crosslinked/crosslinked collagen were prepared by in situ pH-induced fibrillation of collagen phase and sterilized using gamma rays at 25 KGy. Collagen phase is crosslinked using genipin, a bio-based crosslinker that introduces flexible crosslinks. Microscopy studies of the prepared materials showed nanostructured fibrous collagen and cellulose dispersed in collagen matrix. Mechanical performance of the sterilized nanocomposites was close to that of natural ligament and tendon, in simulated body conditions. Cytocompatibility studies indicated that these nanocomposites allowed human ligament cell and human endothelial cell adhesion, growth, and differentiation; which is eminently favourable to ligament tissue engineering.
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| 29. |
- Mindemark, Jonas, et al.
(författare)
-
Low Charge Density Cationic Polymers for Gene Delivery : Exploring the Influence of Structural Elements on In Vitro Transfection
- 2012
-
Ingår i: Macromolecular Bioscience. - : Wiley-VCH Verlagsgesellschaft. - 1616-5187 .- 1616-5195. ; 12:6, s. 840-848
-
Tidskriftsartikel (refereegranskat)abstract
- A series of end-functionalized poly(trimethylene carbonate) DNA carriers, characterized by low cationic charge density and pronounced hydrophobicity, was used to study structural effects on in vitro gene delivery. As the DNA-binding moieties were identical in all polymer structures, the differences observed between the different polymers were directly related to the functionality and length of the polymer backbone. The transfection efficiency and cytotoxicity of the polymer/DNA complexes were thus found to be dependent on a combination of polymer charge density and functionality, highlighting the importance of such structural considerations in the development of materials for efficient gene delivery.
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| 30. |
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| 31. |
- Parlak, Onur, et al.
(författare)
-
Bacterial Sensing and Biofilm Monitoring for Infection Diagnostics
- 2020
-
Ingår i: Macromolecular Bioscience. - : Wiley-VCH Verlag. - 1616-5187 .- 1616-5195.
-
Tidskriftsartikel (refereegranskat)abstract
- Recent insights into the rapidly emerging field of bacterial sensing and biofilm monitoring for infection diagnostics are discussed as well as recent key developments and emerging technologies in the field. Electrochemical sensing of bacteria and bacterial biofilm via synthetic, natural, and engineered recognition, as well as direct redox-sensing approaches via algorithm-based optical sensing, and tailor-made optotracing technology are discussed. These technologies are highlighted to answer the very critical question: “how can fast and accurate bacterial sensing and biofilm monitoring be achieved? Following on from that: “how can these different sensing concepts be translated for use in infection diagnostics? A central obstacle to this transformation is the absence of direct and fast analysis methods that provide high-throughput results and bio-interfaces that can control and regulate the means of communication between biological and electronic systems. Here, the overall progress made to date in building such translational efforts at the level of an individual bacterial cell to a bacterial community is discussed.
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| 32. |
- Podiyan, Oommen, et al.
(författare)
-
Tailored Doxorubicin-Hyaluronan Conjugate as a Potent Anticancer Glyco-Drug : An Alternative to Prodrug Approach
- 2014
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 14:3, s. 327-333
-
Tidskriftsartikel (refereegranskat)abstract
- Releasibility of doxorubicin from drug-conjugates is believed to be a prerequisite for its anti- cancer activity. Here, a new glyco-drug approach that circumvents the releasibility restriction is reported, opening a new possibility to design efficient, target specific drug delivery system. It is discovered that stable amide coupling of doxorubicin (DOX) tohyaluronan (HA) shows dose dependent cytotoxicity to CD44 positive human coloncancer cells (HCT116) as compared to human breast cancer cells(MCF-7) and mouse fibroblast cells (NIH-3T3), which express less CD44 receptor. This direct conjugation approach is an easy scalable strategy that could be adopted to design innocuous anti-tumor nanoparticle formulations.
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| 33. |
- Ramstedt, Madeleine, et al.
(författare)
-
Evaluating Efficacy of Antimicrobial and Antifouling Materials for Urinary Tract Medical Devices : Challenges and Recommendations
- 2019
-
Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195. ; 19:5
-
Forskningsöversikt (refereegranskat)abstract
- In Europe, the mean incidence of urinary tract infections in intensive care units is 1.1 per 1000 patient‐days. Of these cases, catheter‐associated urinary tract infections (CAUTI) account for 98%. In total, CAUTI in hospitals is estimated to give additional health‐care costs of £1–2.5 billion in the United Kingdom alone. This is in sharp contrast to the low cost of urinary catheters and emphasizes the need for innovative products that reduce the incidence rate of CAUTI. Ureteral stents and other urinary‐tract devices suffer similar problems. Antimicrobial strategies are being developed, however, the evaluation of their efficacy is very challenging. This review aims to provide considerations and recommendations covering all relevant aspects of antimicrobial material testing, including surface characterization, biocompatibility, cytotoxicity, in vitro and in vivo tests, microbial strain selection, and hydrodynamic conditions, all in the perspective of complying to the complex pathology of device‐associated urinary tract infection. The recommendations should be on the basis of standard assays to be developed which would enable comparisons of results obtained in different research labs both in industry and in academia, as well as provide industry and academia with tools to assess the antimicrobial properties for urinary tract devices in a reliable way.
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| 34. |
- Russo, Daniela, et al.
(författare)
-
Conformation of Myoglobin-Poly(Ethyl Ethylene Phosphate) Conjugates Probed by SANS : Correlation with Polymer Grafting Density and Interaction.
- 2021
-
Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195. ; 21:2
-
Tidskriftsartikel (refereegranskat)abstract
- One can take advantage of the influence of a polymer conjugated with a protein to control the thermal stability and the deployment of the protein. Here, the structural properties are reported of the protein-polymer conjugate myoglobin (Mb)-poly(ethyl ethylene phosphate) (PEEP) in the native and unfolded conformations, in order to understand the respective roles of the protein and of the polymer size in the stability of the conjugate. The effect is also investigated of the grafting density of the linear biodegradable polyphosphoesters covalently attached to the protein. It is observed that, while the conjugation process at room temperature does not modify the secondary and tertiary structure of the Mb, the unfolding process, as a function of temperature, depends on the grafting density. Small angle neutron scattering reveals that, at room temperature, conjugation does not alter the size of the native protein and that the thickness of the polymer shell around the protein increases as a function of grafting density and of polymer molecular weight. The denatured form of all conjugates is described by an unfolded chain and a correlation length due to the presence of local stiffness.
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| 35. |
- Sharifi, Sina, et al.
(författare)
-
Electron Beam Sterilization of Poly(Methyl Methacrylate)-Physicochemical and Biological Aspects
- 2021
-
Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195. ; 21:4
-
Tidskriftsartikel (refereegranskat)abstract
- Electron beam (E-beam) irradiation is an attractive and efficient method for sterilizing clinically implantable medical devices made of natural and/or synthetic materials such as poly(methyl methacrylate) (PMMA). As ionizing irradiation can affect the physicochemical properties of PMMA, understanding the consequences of E-beam sterilization on the intrinsic properties of PMMA is vital for clinical implementation. A detailed assessment of the chemical, optical, mechanical, morphological, and biological properties of medical-grade PMMA after E-beam sterilization at 25 and 50 kiloGray (kGy) is reported. Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry studies indicate that E-beam irradiation has minimal effect on the chemical properties of the PMMA at these doses. While 25 kGy irradiation does not alter the mechanical and optical properties of the PMMA, 50 kGy reduces the flexural strength and transparency by 10% and 2%, respectively. Atomic force microscopy demonstrates that E-beam irradiation reduces the surface roughness of PMMA in a dose dependent manner. Live-Dead, AlamarBlue, immunocytochemistry, and complement activation studies show that E-beam irradiation up to 50 kGy has no adverse effect on the biocompatibility of the PMMA. These findings suggest that E-beam irradiation at 25 kGy may be a safe and efficient alternative for PMMA sterilization.
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| 36. |
- Sherrell, Peter, 1986-, et al.
(författare)
-
Rational Design of a Conductive Collagen Heart Patch
- 2017
-
Ingår i: Macromolecular Bioscience. - : Wiley-VCH Verlagsgesellschaft. - 1616-5187 .- 1616-5195. ; 17:7
-
Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular diseases, including myocardial infarction, are the cause of significant morbidity and mortality globally. Tissue engineering is a key emerging treatment method for supporting and repairing the cardiac scar tissue caused by myocardial infarction. Creating cell supportive scaffolds that can be directly implanted on a myocardial infarct is an attractive solution. Hydrogels made of collagen are highly biocompatible materials that can be molded into a range of shapes suitable for cardiac patch applications. The addition of mechanically reinforcing materials, carbon nanotubes, at subtoxic levels allows for the collagen hydrogels to be strengthened, up to a toughness of 30 J m-1 and a two to threefold improvement in Youngs' modulus, thus improving their viability as cardiac patch materials. The addition of carbon nanotubes is shown to be both nontoxic to stem cells, and when using single-walled carbon nanotubes, supportive of live, beating cardiac cells, providing a pathway for the further development of a cardiac patch.
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| 37. |
- Sundelöf, Lars-Olof
(författare)
-
The Svedberg in My Memory
- 2010
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 10:7, s. 689-692
-
Tidskriftsartikel (refereegranskat)
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| 38. |
- Tengdelius, Mattias, et al.
(författare)
-
Fucoidan-Mimetic Glycopolymers as Tools for Studying Molecular and Cellular Responses in Human Blood Platelets
- 2017
-
Ingår i: Macromolecular Bioscience. - Weinheim, Germany : Wiley-VCH Verlagsgesellschaft. - 1616-5187 .- 1616-5195. ; 17:2
-
Tidskriftsartikel (refereegranskat)abstract
- The marine sulfated polysaccharide fucoidan displays superior ability to induce platelet aggregation compared to other sulfated polysaccharides. As such, it is an attractive tool for studying molecular and cellular responses in activated platelets. The heterogeneous structure, however, poses a problem in such applications. This study describes the synthesis of sulfated α-l-fucoside-pendant poly(methacryl amides) with homogeneous structures. By using both thiol-mediated chain transfer and reversible addition-fragmentation chain transfer polymerization techniques, glycopolymers with different chain lengths are obtained. These glycopolymers show platelet aggregation response and surface changes similar to those of fucoidan, and cause platelet activation through intracellular signaling as shown by extensive protein tyrosine phosphorylation. As the platelet activating properties of the glycopolymers strongly mimic those of fucoidan, this study concludes these fucoidan-mimetic glycopolymers are unique tools for studying molecular and cellular responses in human blood platelets.
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| 39. |
- Tyson, Therese, et al.
(författare)
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Functional and highly porous scaffolds for biomedical applications
- 2011
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 11:10, s. 1432-1442
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Tidskriftsartikel (refereegranskat)abstract
- Highly porous functional scaffolds were obtained from linear and cross-linked multifunctional poly(ε-caprolactone) and poly(L-lactide). The polymers were synthesized by ring-opening polymerization of ε-caprolactone and L-lactide using poly(but-2-ene-1,4-diyl malonate) (PBM) as macroinitiator and stannous 2-ethylhexanoate. The presence of a double bond in each repeating unit of PBM enabled cross-linking of both scaffolds and films. Soft and flexible scaffolds were created from cross-linked PBM. The mechanical properties of scaffolds and films were evaluated under cyclic conditions, with a focus on the compositions and molecular weights. It was obvious that PBM in the polymers and its cross-linking ability resulted in tunable material characteristics, including an increased ability to recover after repeated loading.
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| 40. |
- van der Spoel, David, et al.
(författare)
-
Proteins, Lipids, and Water in the Gas Phase
- 2011
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 11:1, s. 50-59
-
Tidskriftsartikel (refereegranskat)abstract
- Evidence from mass-spectrometry experiments and molecular dynamics simulations suggests that it is possible to transfer proteins, or in general biomolecular aggregates, from solution to the gas-phase without grave impact on the structure. If correct, this allows interpretation of such experiments as a probe of physiological behavior. Here, we survey recent experimental results from mass spectrometry and ion-mobility spectroscopy and combine this with observations based on molecular dynamics simulation, in order to give a comprehensive overview of the state of the art in gas-phase studies. We introduce a new concept in protein structure analysis by determining the fraction of the theoretical possible numbers of hydrogen bonds that are formed in solution and in the gas-phase. In solution on average 43% of the hydrogen bonds is realized, while in vacuo this fraction increases to 56%. The hydrogen bonds stabilizing the secondary structure (alpha-helices, beta-sheets) are maintained to a large degree, with additional hydrogen bonds occurring when side chains make new hydrogen bonds to rest of the protein rather than to solvent. This indicates that proteins that are transported to the gas phase in a native-like manner in many cases will be kinetically trapped in near-physiological structures. Simulation results for lipid-and detergent-aggregates and lipid-coated (membrane) proteins in the gas phase are discussed, which in general point to the conclusion that encapsulating proteins in "something'' aids in the conservation of native-like structure. Isolated solvated micelles of cetyl-tetraammonium bromide quickly turn into reverse micelles whereas dodecyl phosphocholine micelles undergo much slower conversions, and do not quite reach a reverse micelle conformation within 100 ns.
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| 41. |
- Védie, Elora, et al.
(författare)
-
Influence of Sharklet-Inspired Micropatterned Polymers on Spatio-Temporal Variations of Marine Biofouling
- 2022
-
Ingår i: Macromolecular Bioscience. - : John Wiley and Sons Inc. - 1616-5187 .- 1616-5195. ; 22:11
-
Tidskriftsartikel (refereegranskat)abstract
- This article aims to show the influence of surface characteristics (microtopography, chemistry, mechanical properties) and seawater parameters on the settlement of marine micro- and macroorganisms. Polymers with nine microtopographies, three distinct mechanical properties, and wetting characteristics are immersed for one month into two contrasting coastal sites (Toulon and Kristineberg Center) and seasons (Winter and Summer). Influence of microtopography and chemistry on wetting is assessed through static contact angle and captive air bubble measurements over 3-weeks immersion in artificial seawater. Microscopic analysis, quantitative flow cytometry, metabarcoding based on the ribulose biphosphate carboxylase (rbcL) gene amplification, and sequencing are performed to characterize the settled microorganisms. Quantification of macrofoulers is done by evaluating the surface coverage and the type of organism. It is found that for long static in situ immersion, mechanical properties and non-evolutive wettability have no major influence on both abundance and diversity of biofouling assemblages, regardless of the type of organisms. The apparent contradiction with previous results, based on model organisms, may be due to the huge diversity of marine environments, both in terms of taxa and their size. Evolutive wetting properties with wetting switching back and forth over time have shown to strongly reduce the colonization by macrofoulers. © 2022 The Authors.
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| 42. |
- von Mentzer, Ula, 1995, et al.
(författare)
-
Biomaterial Integration in the Joint: Pathological Considerations, Immunomodulation, and the Extracellular Matrix
- 2022
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 22:7
-
Forskningsöversikt (refereegranskat)abstract
- Defects of articular joints are becoming an increasing societal burden due to a persistent increase in obesity and aging. For some patients suffering from cartilage erosion, joint replacement is the final option to regain proper motion and limit pain. Extensive research has been undertaken to identify novel strategies enabling earlier intervention to promote regeneration and cartilage healing. With the introduction of decellularized extracellular matrix (dECM), researchers have tapped into the potential for increased tissue regeneration by designing biomaterials with inherent biochemical and immunomodulatory signals. Compared to conventional and synthetic materials, dECM-based materials invoke a reduced foreign body response. It is therefore highly beneficial to understand the interplay of how these native tissue-based materials initiate a favorable remodeling process by the immune system. Yet, such an understanding also demands increasing considerations of the pathological environment and remodeling processes, especially for materials designed for early disease intervention. This knowledge will avoid rejection and help predict complications in conditions with inflammatory components such as arthritides. This review outlines general issues facing biomaterial integration and emphasizes the importance of tissue-derived macromolecular components in regulating essential homeostatic, immunological, and pathological processes to increase biomaterial integration for patients suffering from joint degenerative diseases.
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| 43. |
- Wahlund, Per-Olof, et al.
(författare)
-
Phase Separations in Water-Salt Solutions of Polyelectrolyte Complexes Formed by RNA and Polycations: Comparison with DNA Complexes.
- 2003
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 3:8, s. 404-411
-
Tidskriftsartikel (refereegranskat)abstract
- Formation of insoluble polyelectrolyte complexes (PECs) between RNA and polycations was followed by measuring the residual RNA absorbance in the solution after separation of the precipitate. The polycations studied were poly(N,N-dimethyldiallylammonium) chloride (pendant type) and 2,5-ionene bromide (integral type) with quaternary amino groups in every monomer unit. The data obtained were compared with the results of analogous studies of DNA-containing PECs. This study is a part of a project aimed at the specific separation of plasmid DNA from RNA, a major problem in the preparative isolation of plasmid DNA. We thus deliberately chose a heterogenous RNA sample as it represents the RNA present in a real cell extract. In contrast to the exhaustive precipitation of DNA observed at certain values, a significant part of RNA was nonprecipitated at any = [+]/[-], that is, at any ratio of positively charged quaternary amino groups and negatively charged phosphate groups. The addition of sodium chloride increased the nonprecipitated fraction of RNA. DNA, on the other hand, was completely precipitated by both polycations at > 0.7. The less effective precipitation of RNA was probably due to the presence of a considerable fraction of short-chained molecules, incapable of forming a sufficient cooperative system of salt bonds with the polycation. This assumption was supported by a separate experiment, in which the precipitation behavior of RNA fractions of different molecular masses was investigated. The same tendency, while less pronounced, was also ascertained for PECs formed by polycations with DNA fractions of different molecular masses. The possibility of using the revealed differences between DNA and RNA behavior for effective precipitation procedure useful in bioseparation is discussed. The difference in the precipitation behavior of nucleic acids of different molecular masses means there is a possibility for developing an enzymatic assay for DNAase and RNAase activity.
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| 44. |
- Wigenius, Jens A., 1975-, et al.
(författare)
-
Interactions Between a Luminescent Conjugated Oligoelectrolyte and Insulin During Early Phases of Amyloid Formation
- 2011
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 11:8, s. 1120-1127
-
Tidskriftsartikel (refereegranskat)abstract
- Aggregates of misfolded proteins play an important role in diseases such as Alzheimer's. Here it is demonstrated how the anionic oligothiophene p-FTAA interacts with and influences pre-fibrillar protein assemblies during the earlier stages of in vitro fibrillation. Conjugated polythiophenes have previously been demonstrated to detect and discriminate between different types of protein aggregates and also introduce luminescent or conductive properties to these nanoscale fiber structures. Fluorescence spectroscopy, DLS, TEM and FCS are employed to follow the interplay between p-FTAA and insulin during in vitro fibrillation.
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| 45. |
- Wigenius, Jens, et al.
(författare)
-
Supramolecular Assembly of Designed α-Helical Polypeptide-Based Nanostructures and Luminescent Conjugated Polyelectrolytes
- 2010
-
Ingår i: Macromolecular Bioscience. - : John Wiley & Sons. - 1616-5187 .- 1616-5195. ; 10:8, s. 836-841
-
Tidskriftsartikel (refereegranskat)abstract
- Designed polypeptides with controllable folding properties are utilized as supramolecular templates for fabrication of ordered nanoscale molecular and fibrous assemblies of luminescent conjugated polymers (LCPs). The properties of the LCPs as well as the three dimensional conformation of the polypeptide-scaffold determine how the polymers are arranged in the supramolecular construct, which highly affects the properties of the hybrid material. The ability to control the polypeptide conformation and assembly into fibers provide a promising route for tuning the optical properties of LCPs and for fabrication of complex functional supramolecules with well defined structural properties.
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| 46. |
- Wu, Duo, et al.
(författare)
-
Starch Derived Nanosized Graphene Oxide Functionalized Bioactive Porous Starch Scaffolds
- 2017
-
Ingår i: Macromolecular Bioscience. - : Wiley-VCH Verlagsgesellschaft. - 1616-5187 .- 1616-5195. ; 17:6
-
Tidskriftsartikel (refereegranskat)abstract
- A fully starch-derived bioactive 3D porous scaffold is developed. The bioactivity is introduced through nanosized graphene oxide (nGO) derived from starch by microwave-assisted degradation to carbon spheres and further oxidation to GO nanodots. nGO is covalently attached to starch to prepare functionalized starch (SNGO) via an esterification reaction. nGO and SNGO exhibit no cytotoxicity to MG63 at least up to 1000 µg mL−1 under (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Porous scaffolds consisting of starch and SNGO (S/SNGO) or nGO (S/nGO) are prepared by freeze drying. The porosity and water uptake ability of the scaffolds depend on the concentration of nGO. Moreover, nGO, as a bioactive nanofiller, functions as an effective anchoring site for inducing CaP recrystallization in simulated body fluid. Among all modified starch-based scaffolds, the S/SNGO scaffold containing the highest concentration of covalently attached SNGO (50%) induces the largest amount of hydroxyapatite, a type of CaP crystal that is closest to bone. The prepared 3D porous nGO functionalized scaffold, thus, exhibits potential promise for bone/cartilage tissue engineering. (Figure presented.).
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| 47. |
- Xiao, Yan, et al.
(författare)
-
Systematic Comparison of HEA and HEMA as Initiators in Enzymatic Ring-Opening Polymerizations
- 2009
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 9:7, s. 713-720
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Tidskriftsartikel (refereegranskat)abstract
- Two initiators (HEA and HEMA) containing a cleavable ester bond were compared in the lipase-catalyzed ROP of CL and PDL. HEA and HEMA displayed similar reaction efficiencies as initiators (acyl acceptors) in the enzymatic ROP. However, transacylation reactions were found to be 15 times faster on the HEA-initiated polyesters as compared with the HEAAA initiated polyesters (HEA/HEMA moieties as acyl donors). While in both cases the amount of HEA- and HEMA-initiated polymers could be maximized by H short reaction times, a well-defined (meth)acrylation by this approach was not possible. Our results show that trans esterification reactions are present at high rates throughout the enzyme-catalyzed ROP.
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| 48. |
- Yassin, Mohammed A., et al.
(författare)
-
3D and Porous RGDC-Functionalized Polyester-Based Scaffolds as a Niche to Induce Osteogenic Differentiation of Human Bone Marrow Stem Cells
- 2019
-
Ingår i: Macromolecular Bioscience. - : WILEY-V C H VERLAG GMBH. - 1616-5187 .- 1616-5195. ; 19:6
-
Tidskriftsartikel (refereegranskat)abstract
- Polyester-based scaffolds covalently functionalized with arginine-glycine-aspartic acid-cysteine (RGDC) peptide sequences support the proliferation and osteogenic differentiation of stem cells. The aim is to create an optimized 3D niche to sustain human bone marrow stem cell (hBMSC) viability and osteogenic commitment, without reliance on differentiation media. Scaffolds consisting of poly(lactide-co-trimethylene carbonate), poly(LA-co-TMC), and functionalized poly(lactide) copolymers with pendant thiol groups are prepared by salt-leaching technique. The availability of functional groups on scaffold surfaces allows for an easy and straightforward method to covalently attach RGDC peptide motifs without affecting the polymerization degree. The strategy enables the chemical binding of bioactive motifs on the surfaces of 3D scaffolds and avoids conventional methods that require harsh conditions. Gene and protein levels and mineral deposition indicate the osteogenic commitment of hBMSC cultured on the RGDC functionalized surfaces. The osteogenic commitment of hBMSC is enhanced on functionalized surfaces compared with nonfunctionalized surfaces and without supplementing media with osteogenic factors. Poly(LA-co-TMC) scaffolds have potential as scaffolds for osteoblast culture and bone grafts. Furthermore, these results contribute to the development of biomimetic materials and allow a deeper comprehension of the importance of RGD peptides on stem cell transition toward osteoblastic lineage.
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| 49. |
- Yassin, Mohammed A., et al.
(författare)
-
A Copolymer Scaffold Functionalized with Nanodiamond Particles Enhances Osteogenic Metabolic Activity and Bone Regeneration
- 2017
-
Ingår i: Macromolecular Bioscience. - : WILEY-V C H VERLAG GMBH. - 1616-5187 .- 1616-5195. ; 17:6
-
Tidskriftsartikel (refereegranskat)abstract
- Functionalizing polymer scaffolds with nanodiamond particles (nDPs) has pronounced effect on the surface properties, such as improved wettability, an increased active area and binding sites for cellular attachment and adhesion, and increased ability to immobilize biomolecules by physical adsorption. This study aims to evaluate the effect of poly(l-lactide-co-e-caprolactone) (poly(LLA-co-CL)) scaffolds, functionalized with nDPs, on bone regeneration in a rat calvarial critical size defect. Poly(LLA-co-CL) scaffolds functionalized with nDPs are also compared with pristine scaffolds with reference to albumin adsorption and seeding efficiency of bone marrow stromal cells (BMSCs). Compared with pristine scaffolds, the experimental scaffolds exhibit a reduction in albumin adsorption and a significant increase in the seeding efficiency of BMSCs (p = 0.027). In the calvarial defects implanted with BMSC-seeded poly(LLA-co-CL)/ nDPs scaffolds, live imaging at 12 weeks discloses a significant increase in osteogenic metabolic activity (p = 0.016). Microcomputed tomography, confirmed by histological data, reveals a substantial increase in bone volume (p = 0.021). The results show that compared with conventional poly(LLA-co-CL) scaffolds those functionalized with nDPs promote osteogenic metabolic activity and mineralization capacity. It is concluded that poly(LLA-co-CL) composite matrices functionalized with nDPs enhance osteoconductivity and therefore warrant further study as potential scaffolding material for bone tissue engineering.
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| 50. |
- Zhang, Ren, et al.
(författare)
-
Phospholipid Polymer Hydrogel Matrices with Dually Immobilized Cytokines for Accelerating Secretion of the Extracellular Matrix by Encapsulated Cells
- 2020
-
Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5187 .- 1616-5195. ; 20:8
-
Tidskriftsartikel (refereegranskat)abstract
- Construction of 3D tissues by various types of cells with specific characteristics is an important and fundamental technology in tissue reconstruction medicine and animal-free diagnosis system. To do so, an excellent extracellular matrix (ECM) is needed for encapsulation of cells and maintaining cell activity. Spontaneously forming hydrogel matrix is used by complexation between two water-soluble polymers, 2-methacryloyloxyethyl phosphorylcholine polymer bearing phenylboronic acid groups and poly(vinyl alcohol). Two cytokines for cell proliferation are immobilized in the hydrogel matrix to control the activities of the encapsulated cells. The cytokine-immobilized hydrogel matrix can encapsulate both L929 fibroblasts and normal human dermal fibroblasts under mild condition. The physical properties of the hydrogel matrix can follow the proliferation process of the encapsulated cells. The encapsulated cells secrete ECM in the polymer hydrogel networks upon 3D culturing for 7 days. Consequently, the tissue-mimicking ECM hybrid hydrogels are fabricated successfully.
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