An official website of the United States government
Chitosan nanofiber membranes are recognized as functional antimicrobial materials, as they can effectively provide a barrier that guides tissue growth and supports healing. Methods to stabilize nanofibers in aqueous solutions include acylation with fatty acids. Modification with fatty acids that also have antimicrobial and biofilm-resistant properties may be particularly beneficial in tissue regeneration applications. This study investigated the ability to customize the fatty acid attachment by acyl chlorides to include antimicrobial 2-decenoic acid. Synthesis of 2-decenoyl chloride was followed by acylation of electrospun chitosan membranes in pyridine. Physicochemical properties were characterized through scanning electron microscopy, FTIR, contact angle, and thermogravimetric analysis. The ability of membranes to resist biofilm formation by S. aureus and P. aeruginosa was evaluated by direct inoculation. Cytocompatibility was evaluated by adding membranes to cultures of NIH3T3 fibroblast cells. Acylation with chlorides stabilized nanofibers in aqueous media without significant swelling of fibers and increased hydrophobicity of the membranes. Acyl-modified membranes reduced both S. aureus and P.aeruginosa bacterial biofilm formation on membrane while also supporting fibroblast growth. Acylated chitosan membranes may be useful as wound dressings, guided regeneration scaffolds, local drug delivery, or filtration.
more »
« less
This content will become publicly available on June 1, 2026
Lipid-Functionalized Electrospun Chitosan Gauze Performs Comparably to Standard of Care in Contaminated Complex Trauma Model
(1) Background: Musculoskeletal trauma from combat wounds, accidents, or surgeries is highly associated with infections and hospitalization. The current “gold standard” for such injuries when access to hospitals is limited is administering antibiotics and opioids; however, they are not ideal treatments due to their contributions to antibiotic resistance and the opioid epidemic. Electrospun chitosan acylated with lipids and loaded with hydrophobic drugs has been shown to release the therapeutics systemically and to prevent infections. (2) Methods: Electrospun chitosan membranes (ESCMs) were fabricated and acylated using decanoyl chloride. FTIR was used to confirm acylation through the presence of ester bonds and acyl chains. ESCMs were loaded with the quorum-sensing molecule cis-2-decenoic acid (C2DA) and the local anesthetic bupivacaine and then implanted in rat femurs for 3 days. Afterward, the rats were euthanized, and CFUs were measured on retrieved bone, tissue, and treatment material. (3) Conclusions: While ESCMs prevented bacterial growth on the surface of the material, controls outperformed treatment groups. This is possibly due to bupivacaine’s role in inhibiting sodium channels, which favors the production of Th2-type cytokines associated with immune response suppression. Furthermore, ESCMs provide a large surface area for bacteria to grow on and form bridges between nanofibers.
more »
« less
- Award ID(s):
- 1945094
- PAR ID:
- 10595598
- Publisher / Repository:
- Lipidology
- Date Published:
- Journal Name:
- Lipidology
- Volume:
- 2
- Issue:
- 2
- ISSN:
- 2813-7086
- Page Range / eLocation ID:
- 7
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
null (Ed.)Thermosensitive chitosan hydrogels—renewable, biocompatible materials—have many applications as injectable biomaterials for localized drug delivery in the treatment of a variety of diseases. To combat infections such as Staphylococcus aureus osteomyelitis, localized antibiotic delivery would allow for higher doses at the site of infection without the risks associated with traditional antibiotic regimens. Fosfomycin, a small antibiotic in its own class, was loaded into a chitosan hydrogel system with varied beta-glycerol phosphate (β-GP) and fosfomycin (FOS) concentrations. The purpose of this study was to elucidate the interactions between FOS and chitosan hydrogel. The Kirby Bauer assay revealed an unexpected concentration-dependent inhibition of S. aureus, with reduced efficacy at the high FOS concentration but only at the low β-GP concentration. No effect of FOS concentration was observed for the planktonic assay. Rheological testing revealed that increasing β-GP concentration increased the storage modulus while decreasing gelation temperature. NMR showed that FOS was removed from the liquid portion of the hydrogel by reaction over 12 h. SEM and FTIR confirmed gels degraded and released organophosphates over 5 days. This work provides insight into the physicochemical interactions between fosfomycin and chitosan hydrogel systems and informs selection of biomaterial components for improving infection treatment.more » « less
-
Abstract Corticosteroid-eluting endotracheal tubes (ETTs) were developed and employed in a swine laryngotracheal injury model to maintain airway patency and provide localized drug delivery to inhibit fibrotic scarring. Polycaprolactone (PCL) fibers with or without dexamethasone were electrospun onto the ETT surface PCL-only coated ETTs and placed in native airways of 18 Yorkshire swine. Regular and dexamethasone-PCL coated ETTs were placed in airways of another 18 swine injured by inner laryngeal mucosal abrasion. All groups were evaluated after 3, 7 and 14 days (n = 3/treatment/time). Larynges were bisected and localized stiffness determined by normal indentation, then sequentially matched with histological assessment. In the native airway, tissue stiffness with PCL-only ETT placement increased significantly from 3 to 7 days (p = 0.0016) and 3 to 14 days (p < 0.0001) while dexamethasone-PCL ETT placement resulted in stiffness decreasing from 7 to 14 days (p = 0.031). In the injured airway, localized stiffness at 14 days was significantly greater after regular ETT placement (23.1 ± 0.725 N/m) versus dexamethasone-PCL ETTs (17.10 ± 0.930 N/m,p < 0.0001). Dexamethasone-loaded ETTs were found to reduce laryngotracheal tissue stiffening after simulated intubation injury compared to regular ETTs, supported by a trend of reduced collagen in the basement membrane in injured swine over time. Findings suggest localized corticosteroid delivery allows for tissue stiffness control and potential use as an approach for prevention and treatment of scarring caused by intubation injury.more » « less
-
Phosphorus (P) loss from agro-ecosystems impinges upon P use efficiency by plants and thereby constitutes both agronomic and environmental nuisances. Herein, we report on the potential for controlling P leaching loss and application in crop fertilization through repurposing and nano-functionalizing tripolyphosphate (TPP) as a sole P source. The developed TPP-Chitosan and TPP-Chitosan-ZnO nanofertilizers exhibited positive surface charges, 5.8 and 13.8 mV, and hydrodynamic sizes of 430 and 301 nm, respectively. In soil, nanoformulations of TPP-Chitosan and TPP-Chitosan-ZnO significantly reduced cumulative P leaching during 72 h, reaching 91 and 97% reductions, respectively, compared to a conventional fertilizer, monoammonium phosphate (MAP). Cumulative P leaching after 72 h from these nanofertilizers was, respectively, 84 and 95% lower than from TPP alone. TPP-Chitosan-ZnO was, overall, 65% more effective in reducing P leaching, compared to TPP-Chitosan. Relative to MAP, the wheat plant height was significantly increased by TPP-Chitosan-ZnO by 33.0%. Compared to MAP, TPP-Chitosan and TPP-Chitosan-ZnO slightly increased wheat grain yield by 21 and 30%, respectively. Notably, TPP-Chitosan-ZnO significantly decreased shoot P levels, by 35.5, 47, and 45%, compared to MAP, TPP, and TPP-Chitosan, respectively. Zn release over 72 h from TPP-Chitosan-ZnO was considerably lower, compared to a control, ZnO nanoparticles, and averaged, respectively, 34.7 and 0.065 mg/L, which was 534 times higher for the former. Grain Zn was significantly higher in the TPP-Chitosan treatment, relative to MAP. TPP-Chitosan also significantly mobilized the resident K, S, Mg, and Ca from soil into the plant, helping to improve the overall nutritional quality and supporting the role of chitosan in nutrient mobilization. Taken together, our data highlight the potential for repurposing a non-fertilizer P material, TPP, for agricultural and environmental applications and the effect of applying nanotechnology on such outcomes. Broadly speaking, the reduction in P loss is critical for controlling the eutrophication of water bodies due to nutrient overload and for sustaining the dwindling global P resources.more » « less
-
Electrospinning is a straightforward approach for efficiently creating continuous fibers within the submicron to nanometer size range. Electrospun fibers possess excellent properties like high porosity, large specific surface area, tunable morphology, small diameter, etc., making them desirable in various applications. Because of its various properties, polymer is one of the most used materials as the spinning solution in electrospinning. Electrospun polymeric fibers, by themselves, may serve limited applications. Therefore, they are usually mixed with other materials to serve many applications. There are many ways in which these other materials are mixed with polymers in electrospinning, like doping, surface treatment, functionalization, etc. There are several studies published that report on the various composite fibers produced using electrospinning. However, a review focused solely on the production of heterogeneous fibers, where the electrospun fibers are intrinsically made of more than one material, is lacking. Herein, we review different heterogeneous fibers synthesized using electrospinning and their fabrication methods.more » « less
