| 1. |
- Barreto Henriksson, Helena, et al.
(författare)
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Determination of mechanical and rheological properties of a cell-loaded peptide gel during ECM production
- 2019
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 563, s. 437-444
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Tidskriftsartikel (refereegranskat)abstract
- The development of an injectable biomaterial that supports cell survival and maintains or promotes nucleus pulposus (NP) phenotype could aid delivery of cells to degenerated NPs causing low back pain. Mesenchymal cells were loaded and grown in a synthetic peptide gel, PuraMatrix (R). Cells were observed within the gels over 0-28 days, and accumulation of glycosaminoglycans were detected by histological staining. The mechanical properties of the cell-loaded constructs, and the change of the mechanical properties were studied using stress relaxation of the gels under compression and confinement. The PuraMatrix (R) gel was shown to relax fast on compression indicating that the fluid could easily flow out of the gel, and thus indicating the presence of large pores/voids. The presence of these pores/voids was further supported by high mobility of dextran molecules, determined using fluorescence recovery after photo bleaching. The stress required to deform the cell-loaded constructs to a specific strain increases at day 21, at which point the presence of glycosaminoglycans within the cell-loaded constructs was also observed. The results provide evidence of changes in mechanical properties of the PuraMatrix (R) matrix upon excretion of the extracellular matrix by the cells.
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| 2. |
- Berglund, Per, et al.
(författare)
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Linking Education and Research : A Roadmap for Higher Education Institutions at the Dawn of the Knowledge Society
- 2019
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Ingår i: Linking education and research. - Basel, Switzerland : MDPI. ; , s. 11-33
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In an era characterized by a move towards a “knowledge society”, universities are central in fostering “knowledgeability”, that is the reflexive understanding of knowledge in knowledge societies. The objective of “knowledgeability” can be met through creating a stronger link between education and research. Furthermore, overall student performance, for example in critical thinking and problem solving, can be improved if research-related activities are incorporated into the curriculum.The aim of this paper is to use international examples to discuss the research- education nexus from four different perspectives, namely context, policy, implementation and quality, with case studies from higher education institutions in Singapore and Sweden.We suggest that different integrative technologies can be used to enhance the links, but it will be essential to consider the inputs of training, service and support in using new technology. Interestingly, the act of evaluating the link between education and research will increase awareness of this linkage by stakeholders involved in both education and research. In turn the link can be strengthened, contributing to increased quality in both education and research.
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| 3. |
- Bos, R., et al.
(författare)
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Retention of bacteria on a substratum surface with micro-patterned hydrophobicity
- 2000
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Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 1574-6968 .- 0378-1097. ; 189:2, s. 311-315
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Tidskriftsartikel (refereegranskat)abstract
- Bacteria adhere to almost any surface, despite continuing arguments about the importance of physico-chemical properties of substratum surfaces, such as hydrophobicity and charge in biofilm formation. Nevertheless, in vivo biofilm formation on teeth and also on voice prostheses in laryngectomized patients is less on hydrophobic than on hydrophilic surfaces. With the aid of micro-patterned surfaces consisting of 10-mu m wide hydrophobic lines separated by 20-mu m wide hydrophilic spacings, we demonstrate here, For the first time in one and the same experiment, that bacteria do not have a strong preference for adhesion to hydrophobic or hydrophilic surfaces. Upon challenging the adhering bacteria, after deposition in a parallel plate flow chamber, with a high detachment force, however, bacteria were easily wiped-off hydrophobic lines, most notably when these lines were oriented parallel to the direction of flow. Adhering bacteria detached slightly less from the hydrophilic spacings in between, but preferentially accumulated adhering on the hydrophilic regions close to the interface between the hydrophilic spacings and hydrophobic lines. It is concluded that substratum hydrophobicity is a major determinant of bacterial retention while it hardly influences bacterial adhesion.
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| 4. |
- Denis, F. A., et al.
(författare)
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Protein adsorption on model surfaces with controlled nanotopography and chemistry
- 2002
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 1520-5827 .- 0743-7463. ; 18:3, s. 819-828
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the influence of substratum surface characteristics on protein adsorption processes, we have investigated the adsorption (adsorbed amount, supramolecular organization) of collagen on model substrata exhibiting controlled topography and surface chemistry. Substrata were prepared in two steps: (i) gold deposition onto silicon wafers (smooth substrata) and onto a support with nanoscale protrusions created by colloidal lithography (rough substrata); (ii) functionalization with CH3 (hydrophobic) and OH (hydrophilic) groups, using alkanethiol self-assembly. Atomic force microscopy (AFM) images were recorded under water, prior to and after collagen adsorption, and the images were analyzed quantitatively using two independent approaches. On smooth substrata, collagen formed a similar to6 nm thick, homogeneous layer with low roughness on hydrophilic surfaces, and a similar to20 nm thick layer exhibiting elongated aggregated structures on hydrophobic surfaces. Film thickness measurements (AFM) together with X-ray photoelectron spectroscopy (XPS) revealed larger adsorbed amounts on hydrophobic surfaces compared to hydrophilic ones. On rough substrata, the adsorbed amounts were similar to those found on smooth substrata; however, the collagen molecules no longer formed aggregated structures on the hydrophobic surfaces. It is concluded that while the adsorbed amount is only affected by the surface chemistry, the supramolecular organization of the adsorbed layer is controlled both by surface chemistry and topography. The approach presented here will have great value in biophysics for investigating bioadsorption and bioadhesion processes on substrata of defined surface properties.
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| 5. |
- Friese, M. E. J., et al.
(författare)
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Optically driven micromachine elements
- 2001
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 78:4, s. 547-549
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Tidskriftsartikel (refereegranskat)abstract
- We report on a proof of principle demonstration of an optically driven micromachine element. Optical angular momentum is transferred from a circularly polarized laser beam to a birefringent particle confined in an optical tweezers trap. The optical torque causes the particle to spin at up to 350 Hz, and this torque is harnessed to drive an optically trapped microfabricated structure. We describe a photolithographic method for producing the microstructures and show how a light driven motor could be used in a micromachine system.
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| 6. |
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| 7. |
- Gabriel, B. L., et al.
(författare)
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Site-specific adhesion of Staphylococcus epidermidis (RP12) in Ti-Al-V metal systems
- 1994
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 15:8, s. 628-634
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus epidermidis (RP12) adhesion patterns were studied on the following titanium (Ti)-aluminium (Al)-vanadium (V) metal systems: (i) microfabricated samples consisting of Ti, Al and V islands deposited onto Ti or V substrata, (ii) pure Ti, Al and V metals, and (iii) medical grade Ti6Al4-V alloy. All of these surfaces were covered with their respective oxides formed upon exposure of the metals to air. Quantitative analysis of the number of cells bound per unit area indicates that S. epidermidis (RP12) exhibits greatest adhesion to pure V surfaces. When exposed to surfaces having controlled spatial variations in chemical composition on the 10 mu m scale (microfabricated samples), the bacteria preferentially populate V islands versus Ti or Al substrata. In the case of the biphasic Ti6Al4V alloy, the bacteria tend to adhere to V-rich, mixed phase regions and phase boundaries. These findings demonstrate that enhanced and preferential adhesion of S. epidermidis (RP12) occurs on V surfaces in TI-Al-V metal systems and suggest that bacterial interactions are influenced by surface oxide composition.
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| 8. |
- Gloriam, David E., et al.
(författare)
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A Community Standard Format for the Representation of Protein Affinity Reagents
- 2010
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 9:1, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Protein affinity reagents (PARs), most commonly antibodies, are essential reagents for protein characterization in basic research, biotechnology, and diagnostics as well as the fastest growing class of therapeutics. Large numbers of PARs are available commercially; however, their quality is often uncertain. In addition, currently available PARs cover only a fraction of the human proteome, and their cost is prohibitive for proteome scale applications. This situation has triggered several initiatives involving large scale generation and validation of antibodies, for example the Swedish Human Protein Atlas and the German Antibody Factory. Antibodies targeting specific subproteomes are being pursued by members of Human Proteome Organisation (plasma and liver proteome projects) and the United States National Cancer Institute (cancer-associated antigens). ProteomeBinders, a European consortium, aims to set up a resource of consistently quality-controlled protein-binding reagents for the whole human proteome. An ultimate PAR database resource would allow consumers to visit one online warehouse and find all available affinity reagents from different providers together with documentation that facilitates easy comparison of their cost and quality. However, in contrast to, for example, nucleotide databases among which data are synchronized between the major data providers, current PAR producers, quality control centers, and commercial companies all use incompatible formats, hindering data exchange. Here we propose Proteomics Standards Initiative (PSI)-PAR as a global community standard format for the representation and exchange of protein affinity reagent data. The PSI-PAR format is maintained by the Human Proteome Organisation PSI and was developed within the context of ProteomeBinders by building on a mature proteomics standard format, PSI-molecular interaction, which is a widely accepted and established community standard for molecular interaction data. Further information and documentation are available on the PSI-PAR web site. Molecular & Cellular Proteomics 9: 1-10, 2010.
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| 9. |
- Gold, Julie, 1963
(författare)
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Microfabrication for Biological Applications. Preparation, Characterization and Biological Evaluation
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Foreign materials are intentionally placed into patients in the form of medical devices for replacing or repairing damaged portions of the body. Materials also enter the body unintentionally in the form of particulates and fibers, and can then have damaging effects, such as the formation of disease or even cancer. Such is the case for inhaled mineral dusts and asbestos fibers. The interaction between living tissue and a foreign material is, in both cases, governed by the type and state of the host tissue as well as by the physical and chemical properties of the material. Of major importance is the role of material surface properties in reactions occurring at the material-tissue interface. Both the chemical properties and the morphology (i.e., topography, texture, or roughness) of the surface are important. They may act independently or in synergy in producing biological responses to foreign materials. A major goal for future biomaterials research and development is to control biological responses by engineering the surface to carry out specific biological functions. This requires an understanding of the independent roles of chemical versus morphological properties of material surfaces. It is therefore important to be able to systematically and independently vary each of these properties, and to study how they affect biological responses. The latter applies also to materials that unintentionally enter the body. The aim of this thesis work was to develop and apply micro- and nano-fabrication methods to produce well-controlled surfaces and particulates on all biologically relevant size scales. The capabilities of photo- and electron beam lithography to produce systematically and independently varying morphological and chemical features over the size range of nanometers to microns has been demonstrated and critically evaluated. Some of these structures have been used in biological model experiments. The main emphasis has been the development of methodologies to produce, characterize, and apply microfabricated samples for studying cellular interactions. Samples containing spatially patterned, 10 µm square areas of Ti, Al, and V metal films have shown bacterial (S. epidermidis) adhesion preferences for V regions. A second example is the production of free fibers of cross-section 0.1 x 0.5 µm and lengths of 10, 1, or 0.1 µm in gold, titanium, and silicon oxide. The phagocytic response of alveolar macrophages to 10 µm long fibers of titanium and silicon oxide indicate differences owing to differences in fiber material chemistry alone. In addition to these two examples, a variety of structures for potential future biological experiments have been produced. They include 1 - 10 µm features and patterns etched into bulk polymethylmethacrylate or titanium surfaces. The main impact of this work is that it demonstrates the needs and opportunities for microfabrication and nanofabrication in both biomaterials (medical implants and devices, etc.) and respirable fiber research and development. The efforts put forth here therefore form the basis for future applications of micro- and nanofabriaction to biomaterials as well as to various other fields of research.
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| 10. |
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| 11. |
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| 12. |
- Krona, Annika, et al.
(författare)
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Developing cultured meat scaffolds of extruded vegetable-based proteins
- 2017
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Ingår i: Annual Transactions of the Nordic Rheology Society. ; 25, s. 311-
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Tidskriftsartikel (refereegranskat)abstract
- Muscle cells from animals can becultivated in cell culture medium, but to beused as a meat food product, they need asolid matrix to grow on that can alsocontribute to the texture. In this project wehave created promising fibrous growthsubstrates from extruded plant basedproteins that the cells are able to attach toand grow on. Cultured meat is still far froma commercial product, but may, in the longrun, give even tastier, healthier and moreenvironmentally friendly meat products.
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| 13. |
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| 14. |
- Motalleb, Reza, 1985, et al.
(författare)
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In vivo migration of endogenous brain progenitor cells guided by an injectable peptide amphiphile biomaterial
- 2018
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Ingår i: Journal of Tissue Engineering and Regenerative Medicine. - : Hindawi Limited. - 1932-6254 .- 1932-7005. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Biomaterials hold great promise in helping the adult brain regenerate and rebuild after trauma. Peptide amphiphiles (PAs) are highly versatile biomaterials, gelling and forming macromolecular structures when exposed to physiological levels of electrolytes. We are here reporting on the first ever in vivo use of self-assembling PA carrying a Tenascin-C signal (E(2)Ten-C PA) for the redirection of endogenous neuroblasts in the rodent brain. The PA forms highly aligned nanofibers, displaying the migratory sequence of Tenascin-C glycoprotein as epitope. In this in vivo work, we have formed in situ a gel of aligned PA nanofibers presenting a migratory Tenascin-C signal sequence in the ventral horn of the rostral migratory stream, creating a track reaching the neocortex. Seven days posttransplant, doublecortin positive cells were observed migrating inside and alongside the injected biomaterial, reaching the cortex. We observed a 24-fold increase in number of redirected neuroblasts for the E(2)Ten-C PA-injected animals compared to control. We also found injecting the E(2)Ten-C PA to cause minimal neuroinflammatory response. Analysing GFAP(+) astrocytes and Iba1(+) microglia activation, the PA does not elicit a stronger neuroinflammatory response than would be expected from a small needle stab wound. Redirecting endogenous neuroblasts and increasing the number of cells reaching a site of injury using PAs may open up new avenues for utilizing the pool of neuroblasts and neural stem cells within the adult brain for regenerating damaged brain tissue and replacing neurons lost to injury.
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| 15. |
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| 16. |
- Pettersson, Sofia, 1977-
(författare)
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Biodegradable gelatin microcarriers in tissue engineering : In vitro studies on cartilage and bone
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tissue engineering is a multidisciplinary field that combines cells, biomaterial scaffolds and environmental factors to achieve functional tissue repair. This thesis focuses on the use of macroporous gelatin microcarriers as scaffolds in tissue engineering applications, with a special focus on cartilage and bone formation by human adult cells in vitro.In our first study, human articular chondrocytes were seeded on macroporous gelatin microcarriers. The microcarriers were subsequently encapsulated in coagulated blood-derived biological glues and cultured under free-swelling conditions for up to 17 weeks. Even in the absence of recombinant chondrogenic growth factors, the chondrocytes remained viable and metabolically active for the duration of the culture period, as indicated by an increased amount of cell nuclei and extracellular matrix (ECM). The ECM showed several cartilage characteristics, but lacked the cartilage specific collagen type II. Furthermore, ECM formation was seen primarily in a capsule surrounding the tissue-engineered constructs, leading to the conclusion that the used in vitro models were unable to support true cartilage formation.The capacity of human dermal fibroblasts to produce cartilage- and bone-like tissue in the previously mentioned model was also investigated. Under the influence of chondrogenic induction factors, including TGF-β1 and insulin, the fibroblasts produced cartilage specific molecules, as confirmed by indirect immunohistochemistry, however not collagen type II. Under osteogenic induction, by dexamethasone, ascorbate-2-phosphate and β–glycerophosphate, the fibroblasts formed a calcified matrix with bone specific markers, and an alkaline phosphatase assay corroborated a shift towards an osteoblast like phenotype. The osteogenic induction was enhanced by flow-induced shear stress in a spinner flask system.In addition, four different types of gelatin microcarriers, differing by their internal pore diameter and their degree of gelatin cross-linking, were evaluated for their ability to support chondrocyte expansion. Chondrocyte densities on the microcarriers were monitored every other day over a twoweek period, and chondrocyte growth was analyzed by piecewise linear regression and analysis of variance (ANOVA). No differences were seen between the different microcarriers during the first week. However, during the second week of culture both microcarrier pore diameter and gelatin crosslinking had significant impacts on chondrocyte density.Lastly, a dynamic centrifugation regime (f=12.5 mHz for 16 minutes every other day) was administered to chondrocyte-seeded microcarriers, with or without encapsulation in platelet rich plasma (PRP), to study the possible effect of dynamic stimuli on cartilage formation. Presence of PRP enhanced the structural stability of the tissue-engineered constructs, but we were not able to confirm any dose-response pattern between ECM formation and the applied forces. After 12 weeks, distinct gelatin degradation had occurred independent of both dynamic stimuli and presence of PRP.In summary, this thesis supports a plausible use for gelatin microcarriers in tissue engineering of cartilage and bone. Microcarrier characteristics, specifically gelatin cross-linking and pore diameter, have been shown to affect chondrocyte expansion. In addition, the use of human dermal fibroblasts as an alternative cell source for cartilage and bone formation in vitro was addressed.
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| 17. |
- Rasmussen, Martin Krøyer, et al.
(författare)
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Critical review of cultivated meat from a Nordic perspective
- 2024
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Ingår i: Trends in Food Science and Technology. - 0924-2244. ; 144
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Forskningsöversikt (refereegranskat)abstract
- Background: Cultivated meat is a novel technology with the potential to partly substitute conventional meat in the future. Production of cultivated meat is based on biotechnology for tissue engineering, up-scaling of cell cultures and stem-cell differentiation, providing the basis for large-scale proliferation of the parent cell and subsequent differentiation into primitive skeletal muscle structures known from conventional meat. Development of cultivated meat is considered a socio-technological challenge including a variety of technical, sustainability, ethical, and consumer acceptance issues. Scope and approach: As the Nordic countries share common history and roots of food culture, cultivated meat will be introduced into a socio-cultural context with established food traditions. This review summarizes the current knowledge and activities on the development of cultivated meat in the Nordic countries and considers this novel food product in a specific socio-cultural context. Key findings and conclusions: The production of cultivated meat in the Nordic countries, must encompass solutions that are accepted by the typical Nordic consumer. In general, this favors solutions for cell culturing based on non-GMO cells and locally accessible raw material for cell medias and scaffolding. From the perspective of the Nordic countries, this will improve the environmental, societal, and ethical context of cultivated meat.
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| 18. |
- Schuster, E., et al.
(författare)
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Correlating network structure with functional properties of capillary alginate gels for muscle fiber formation
- 2017
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X .- 1873-7137. ; 72, s. 210-218
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Tidskriftsartikel (refereegranskat)abstract
- Capillary alginate gels have the potential to be used as scaffold for the growth of muscle cells for cultured meat owing to the formation of aligned skeletal muscle cells along the length of self-assembled micro-capillaries within the calcium alginate gel. The functional properties (mechanical and permeability) of the gels were determined and correlated to the nano-lengthscale of the gel network using small-angle X-ray scattering. Calcium ions were let to diffuse into the alginate solution in order to obtain spontaneously formed capillaries. We show that the resulting calcium alginate network is isotropic in the plane perpendicular to the inflow of cross linking ions while anisotropic in the parallel plane. The structural anisotropicity is reflected in the mechanical properties (measured via uniaxial stress relaxation) of the gel, where a larger force is required to compress the gel in the isotropic plane than in the anisotropic plane. The findings suggest that the network is layered, or composed of “sheets” with denser regions of alginate, sheets that are weakly attached to each other, similar to the structure of bacterial cellulose. Such structure would further explain the increased permeability of labeled dextran (as determined using fluorescence recovery after photo-bleaching) that we observed in the alginate gels used in this study, as compared to internally set calcium alginate gel.
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| 19. |
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| 20. |
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| 21. |
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| 22. |
- Thid, Dorota, 1976, et al.
(författare)
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Supported phospholipid bilayers as a platform for neural progenitor cell culture
- 2008
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Ingår i: Journal of Biomedical Materials Research - Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 84:4, s. 940-953
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Tidskriftsartikel (refereegranskat)abstract
- Supported phospholipid bilayers constitute a biomimetic platform for cell behavior studies and a new approach to the design of cell culture substrates. Phosphocholine bilayers are resistant to cell attachment, but can be functionalized with bioactive molecules to promote specific cell interactions. Here, we explore phosphocholine bilayers, functionalized with the laminin-derived IKVAV pentamer, as substrates for attachment, growth, and differentiation of neural progenitor cells (AHPs). By varying peptide concentration (0-10%), we discovered a strongly nonlinear relationship between cell attachment and IKVAV concentration, with a threshold of 1% IKVAV required for attachment, and saturation in cell binding at 3% IKVAV. This behavior, together with the 10-fold reduction in cell attachment when using a jumbled peptide sequence, gives evidence for a specific interaction between IKVAV and its AHP cell-surface receptor. After 8 days in culture, the peptide- functionalized bilayers promoted a high degree of cell cluster formation. This is in contrast to the predominant monolayer growth, observed for these cells on the standard laminin coated growth substrates. The peptide-functionalized bilayer did not induce differentiation levels over those observed for the laminin coated substrates. These results are promising in that peptide-functionalized bilayers can allow attachment and growth of stem cells without induction of differentiation. © 2007 Wiley Periodicals, Inc.
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| 23. |
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| 24. |
- Tymchenko, Nina, 1977, et al.
(författare)
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A novel cell force sensor for quantification of traction during cell spreading and contact guidance
- 2007
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Ingår i: Biophysical Journal. - : Elsevier BV. - 1542-0086 .- 0006-3495. ; 93, s. 335-345
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we present a ridged, microfabricated, force sensor that can be used to investigate mechanical interactions between cells exhibiting contact guidance and the underlying cell culture substrate, and a proof-of-function evaluation of the force sensor performance. The substrates contain arrays of vertical pillars between solid ridges that were microfabricated in silicon wafers using photolithography and deep reactive ion etching. The spring constant of the pillars was measured by atomic force microscopy. For time-lapse experiments, cells were seeded on the pillared substrates and cultured in an on-stage incubator on a microscope equipped with re. flected differential interference contrast optics. Endothelial cells (ECs) and. broblasts were observed during attachment, spreading, and migration. Custom image analysis software was developed to resolve cell borders, cell alignment to the pillars and migration, displacements of individual pillars, and to quantify cell traction forces. Contact guidance classifi. cation was based on cell alignment and movement angles with respect to microfabricated ridges, as well as cell elongation. In initial investigations made with the ridged cell force sensor, we have observed contact guidance in ECs but not in. broblast cells. A difference in maximal amplitude of mechanical forces was observed between a contact-guided and non-contact-guided, but mobile, EC. However, further experiments are required to determine the statistical significance of this observation. By chance, we observed another feature of cell behavior, namely a reversion of cell force direction. The direction of forces measured under rounded. broblast cells changed from outwards during early cell attachment to inwards during further observation of the spreading phase. The range of forces measured under. broblasts (up to 138 nN) was greater than that measured in EC (up to 57 nN), showing that the rigid silicon sensor is capable of resolving a large range of forces, and hence detection of differences in traction forces between cell types. These observations indicate proof-of-function of the ridged cell force sensor to induce contact guidance, and that the pillared cell force sensor constructed in rigid silicon has the necessary sensitivity to detect differences in traction force vectors between different cell phenotypes and morphologies.
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| 25. |
- Tymchenko, Nina, 1977, et al.
(författare)
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Reversible Changes in Cell Morphology due to Cytoskeletal Rearrangements Measured in Real-Time by QCM-D
- 2012
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Ingår i: Biointerphases. - : American Vacuum Society. - 1559-4106 .- 1934-8630. ; 7:1-4, s. 43-9
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Tidskriftsartikel (refereegranskat)abstract
- The mechanical properties and responses of cells to external stimuli (including drugs) are closely connected to important phenomena such as cell spreading, motility, activity, and potentially even differentiation. Here, reversible changes in the viscoelastic properties of surface-attached fibroblasts were induced by the cytoskeleton-perturbing agent cytochalasin D, and studied in realtime by the quartz crystal microbalance with dissipation (QCM-D) technique. QCM-D is a surface sensitive technique that measures changes in (dynamically coupled) mass and viscoelastic properties close to the sensor surface, within a distance into the cell that is usually only a fraction of its size. In this work, QCM-D was combined with light microscopy to study in situ cell attachment and spreading. Overtone-dependent changes of the QCM-D responses (frequency and dissipation shifts) were first recorded, as fibroblast cells attached to protein-coated sensors in a window equipped flow module. Then, as the cell layer had stabilised, morphological changes were induced in the cells by injecting cytochalasin D. This caused changes in the QCM-D signals that were reversible in the sense that they disappeared upon removal of cytochalasin D. These results are compared to other cell QCM-D studies. Our results stress the combination of QCM-D and light microscopy to help interpret QCM-D results obtained in cell assays and thus suggests a direction to develop the QCM-D technique as an even more useful tool for real-time cell studies.
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