| 1. |
- 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.
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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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| 2. |
- Biscari, Giuseppina, et al.
(författare)
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Gellan gum-dopamine mediated in situ synthesis of silver nanoparticles and development of nano/micro-composite injectable hydrogel with antimicrobial activity
- 2024
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 258
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Tidskriftsartikel (refereegranskat)abstract
- Infected skin wounds represent a serious health threat due to the long healing process and the risk of colonization by multi-drug-resistant bacteria. Silver nanoparticles (AgNPs) have shown broad-spectrum antimicrobial activity. This study introduces a novel approach to address the challenge of infected skin wounds by employing gellan gum-dopamine (GG-DA) as a dual-functional agent, serving both as a reducing and capping agent, for the in situ green synthesis of silver nanoparticles. Unlike previous methods, this work utilizes a spray-drying technique to convert the dispersion of GG-DA and AgNPs into microparticles, resulting in nano-into-micro systems (AgNPs@MPs). The microparticles, with an average size of approximately 3 μm, embed AgNPs with a 13 nm average diameter. Furthermore, the study explores the antibacterial efficacy of these AgNPs@MPs directly and in combination with other materials against gram-positive and gram-negative bacteria. The versatility of the antimicrobial material is showcased by incorporating the microparticles into injectable hydrogels. These hydrogels, based on oxidized Xanthan Gum (XGox) and a hyperbranched synthetic polymer (HB10K-G5-alanine), are designed with injectability and self-healing properties through Shiff base formation. The resulting nano-into-micro-into-macro hybrid hydrogel emerges as a promising biomedical solution, highlighting the multifaceted potential of this innovative approach in wound care and infection management.
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| 3. |
- Chang, Tingru, et al.
(författare)
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Effect of blue light illumination on atmospheric corrosion and bacterial adhesion on copper
- 2024
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Ingår i: Corrosion Science. - : Elsevier BV. - 0010-938X .- 1879-0496. ; 230
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Tidskriftsartikel (refereegranskat)abstract
- The effect of blue light on atmospheric corrosion of Cu and on the antimicrobial properties was explored upon exposure mimicking the condition of hygienic surface disinfection. The results show that blue light illumination enhanced the formation of Cu2O, resulting in a slightly increased corrosion resistance of Cu without pre-deposited NaCl, whereas the enhanced formation of Cu2O, CuCl and/or Cu(OH)3Cl on copper with pre-deposited NaCl caused concomitant corrosion product flaking and a reduced corrosion resistance. The blue light induced enhancement of Cu corrosion led to increased surface roughness and more pronounced integration of bacteria within the corrosion products.
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| 4. |
- Fan, Yanmiao, et al.
(författare)
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Dendritic Hydrogels Induce Immune Modulation in Human Keratinocytes and Effectively Eradicate Bacterial Pathogens
- 2021
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 143:41, s. 17180-17190
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Tidskriftsartikel (refereegranskat)abstract
- Infections caused by antibiotic-resistant bacteria are globally a major threat, leading to high mortality rates and increased economic burden. Novel treatment strategies are therefore urgently needed by healthcare providers to protect people. Biomaterials that have inherent antibacterial properties and do not require the use of antibiotics present an attractive and feasible avenue to achieve this goal. Herein, we demonstrate the effect of a new class of cationic hydrogels based on amino-functional hyperbranched dendritic-linear-dendritic copolymers (HBDLDs) exhibiting excellent antimicrobial activity toward a wide range of clinical Gram-positive and Gram-negative bacteria, including drug-resistant strains isolated from wounds. Intriguingly, the hydrogels can induce the expression of the antimicrobial peptides RNase 7 and psoriasin, promoting host-mediated bacterial killing in human keratinocytes (HaCaT). Moreover, treatment with the hydrogels decreased the proinflammatory cytokine IL-1 beta, reactive nitrogen species (NO), and mitochondrial reactive oxygen species (ROS) in S. aureus-infected HaCaT cells, conjunctively resulting in reduced inflammation.
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| 5. |
- Fan, Yanmiao, et al.
(författare)
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Detection of gemcitabine metabolism using 19F-NMR and its impacts on E. coli morphology
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 19F-NMR spectroscopy is a sensitive analytical method to detect the metabolism of fluorine-containing drugs by bacteria. In this study, 19F-NMR was used to achieve the real time detection of metabolic process of gemcitabine (2′, 2′-difluorodeoxycytidine) by Escherichia Coli (E. coli) in the nutrient broth. Both E. coli and Staphylococcus aureus (S. aureus) were used in the metabolism study. E. coli can metabolize gemcitabine, while gemcitabine cannot be metabolized by S. aureus. Our results showed that gemcitabine can be totally metabolized to its inactive form 2′, 2′-difluorodeoxyuridine (dFdU) by E. coli both in Mueller-Hinton broth and M9 minimal salt. The metabolic rate of gemcitabine has a positive correlation with the bacterial concentrations. The metabolism is due to the presence of bacterial cytidine deaminase, and the enzyme inhibitor tetrahydrouridine (THU) can inhibit the gemcitabine metabolism. Scanning electron microscope (SEM) was used to study the effects of gemcitabine metabolism on E. coli morphological changes, and the treated E. coli was 2-3 times longer than the normal bacteria. 19F–NMR was capable to achieve real time detection of gemcitabine metabolism process considering there was no need to separate the bacterial cells from the nutrient medium, this study provided a fast and facile way to detect fluorine-containing drug metabolism by bacteria.
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| 6. |
- Fan, Yanmiao, et al.
(författare)
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Fluorescent silicon nanoparticles as a potential capaturing and imaging agent for Staphylococcus aureus
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Nanomaterials, with various shapes and specific physicochemical properties, have attracted a lot of interest in the biomedical fields. Fluorescent silicon nanoparticles (SiNPs) have shown promise as immunofluorescent cellular imaging agents. In this study, SiNPs were synthesized to explore their potential as bacterial imaging agents. Silicon nanoparticles with amino groups on the surface were prepared using microwave-assisted synthesis method using trisodium citrate as the reducing agent. The obtained SiNPs were characterized using dynamic light scattering (DLS), UV−vis absorption spectroscopy and fluorescence spectrophotometer. And SiNPs were used to study their interactions with both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). The interactions between the prepared SiNPs and bacteria were monitored by the fluorescence microscope, and SiNPs showed a strong interaction with S. aureus. SEM was used to study the morphological changes of S. aureus, and we found that the cell membranes of S. aureus became damaged after the interaction with SiNPs. The amino groups on the surfaces of SiNPs could also be functionalized with other functional groups for other applications.
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| 7. |
- Fan, Yanmiao, et al.
(författare)
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Nanogel encapsulated hydrogels as advanced wound dressings for the controlled delivery of antibiotics
- 2021
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 31
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Tidskriftsartikel (refereegranskat)abstract
- Biocompatible and degradable dual-delivery gel systems based on hyperbrancheddendritic−linear−dendritic copolymers (HBDLDs) is herein conceptualizedand accomplished via thiol-ene click chemistry. The elasticity of thehydrogels is tunable by varying the lengths of PEG (2, 6, 10 kDa) or the dryweight percentages (20, 30, 40 wt%), and are found to be between 2–14.7 kPa,comparable to human skin. The co-delivery of antibiotics is achieved, wherethe hydrophilic drug novobiocin sodium salt (NB) is entrapped within thehydrophilic hydrogel, while the hydrophobic antibiotic ciprofloxacin (CIP) isencapsulated within the dendritic nanogels (DNGs) with hydrophobic cores(DNGs-CIP). The DNGs-CIP with drug loading capacity of 2.83 wt% are thenphysically entrapped within the hybrid hydrogels through UV curing. Thehybrid hydrogels enabled the quick release of NB and prolonged released ofCIP. In vitro cell infection assays showed that the antibiotic-loaded hybridhydrogels are able to treat bacterial infections with significant bacterialreduction. Hybrid hydrogel band aids are fabricated and exhibited betterantibacterial activity compared with commercial antimicrobial band aids.Remarkably, most hydrogels and hybrid hydrogels showed enhanced humandermal cell proliferation and could be degraded into non-toxic constituents,showing great promise as wound dressing materials.
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| 8. |
- Fan, Yanmiao, et al.
(författare)
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Placenta Powder-Infused Thiol-Ene PEG Hydrogels as Potential Tissue Engineering Scaffolds
- 2023
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 24:4, s. 1617-1626
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Tidskriftsartikel (refereegranskat)abstract
- Human placenta is a source of extracellular matrix for tissue engineering. In this study, placenta powder (PP), made from decellularized human placenta, was physically incorporated into synthetic poly(ethylene glycol) (PEG)-based hydrogels via UV-initiated thiol-ene coupling (TEC). The PP-incorporated PEG hydrogels (MoDPEG+) showed tunable storage moduli ranging from 1080 ± 290 to 51,400 ± 200 Pa. The addition of PP (1, 4, or 8 wt %) within the PEG hydrogels increased the storage moduli, with the 8 wt % PP hydrogels showing the highest storage moduli. PP reduced the swelling ratios compared with the pristine hydrogels (MoDPEG). All hydrogels showed good biocompatibility in vitro toward human skin cells and murine macrophages, with cell viability above 91%. Importantly, cells could adhere and proliferate on MoDPEG+ hydrogels due to the bioactive PP, while MoDPEG hydrogels were bio-inert as cells moved away from the hydrogel or were distributed in a large cluster on the hydrogel surface. To showcase their potential use in application-driven research, the MoDPEG+ hydrogels were straightforwardly (i) 3D printed using the SLA technique and (ii) produced via high-energy visible light (HEV-TEC) to populate damaged soft-tissue or bone cavities. Taking advantage of the bioactivity of PP and the tunable physicochemical properties of the synthetic PEG hydrogels, the presented MoDPEG+ hydrogels show great promise for tissue regeneration.
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| 9. |
- Fan, Yanmiao, et al.
(författare)
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Scalable Dendritic Hydrogels Targeting Drug-Resistant Skin Pathogens and the Immunomodulation Activity in Keratinocytes
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Microbial infections caused by antibiotic-resistant bacteria are a major threat to humans, associated with a high mortality and for the society increased economic burden. To address this, a series of cationic hydrogels based on amino-functional hyperbranched dendritic−linear−dendritic copolymers (HBDLDs) were formed easily within 1 min through interactions between the amino-terminated HBDLDs and di(N-hydroxysuccinimide ester) functionalized polyethylene glycol (PEG). The hydrogels exhibited excellent inherent antimicrobial activity towards a wide range of Gram-positive and Gram-negative clinical bacteria including drug-resistant strains, isolated from wounds. In vitro cell infection assays showed that the hydrogels were able to significantly reduce cell infections caused by different strains, with the highest killing efficacy of 96% towards S. aureus. The hydrogels also inhibited the initiation of E. coli biofilm formation. Remarkably, the hydrogels induced the expression of the antimicrobial peptides, RNase 7 and psoriasin, in keratinocytes (HaCaT) which suggests that the hydrogels are likely able to promote host-mediated bacterial killing. The expression of pro-inflammatory cytokine IL-1β, reactive nitrogen species (NO) and mitochondrial reactive oxygen species (ROS) in S. aureus-infected HaCaT cells were reduced after the treatment with the hydrogels. The hydrogels degraded within 24 h, showing great promise for treating skin infections and reducing inflammation.
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| 10. |
- Fan, Yanmiao, et al.
(författare)
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Self-Assembled Polyester Dendrimer/Cellulose Nanofibril Hydrogels with Extraordinary Antibacterial Activity
- 2020
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Ingår i: Pharmaceutics. - : MDPI. - 1999-4923. ; 12:12
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Tidskriftsartikel (refereegranskat)abstract
- Cationic dendrimers are intriguing materials that can be used as antibacterial materials; however, they display significant cytotoxicity towards diverse cell lines at high generations or high doses, which limits their applications in biomedical fields. In order to decrease the cytotoxicity, a series of biocompatible hybrid hydrogels based on cationic dendrimers and carboxylated cellulose nanofibrils were easily synthesized by non-covalent self-assembly under physiological conditions without external stimuli. The cationic dendrimers from generation 2 (G2) to generation 4 (G4) based on trimethylolpronane (TMP) and 2,2-bis (methylol)propionic acid (bis-MPA) were synthesized through fluoride promoted esterification chemistry (FPE chemistry). FTIR was used to show the presence of the cationic dendrimers within the hybrid hydrogels, and the distribution of the cationic dendrimers was even verified using elemental analysis of nitrogen content. The hybrid hydrogels formed from G3 and G4 showed 100% killing efficiency towards Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) with bacterial concentrations ranging from 10(5) CFU/mL to 10(7) CFU/mL. Remarkably, the hybrid hydrogels also showed good biocompatibility most probably due to the incorporation of the biocompatible CNFs that slowed down the release of the cationic dendrimers from the hybrid hydrogels, hence showing great promise as an antibacterial material for biomedical applications.
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