(WHS-P65) Antibacterial Silk Fibroin Based Biofabrics to Treat Chronic P. Aueruginosa Biofilms
Friday, May 17, 2024
7:30 AM – 5:00 PM East Coast USA Time
Pathological biofilm formation is a major issue that restricts the functional use of implants and scaffolds in wound healing, resulting in delayed healing, chronic infections and impaired tissue regeneration. Embedding nanoparticles directly into the wound-bed could be a viable strategy, but present the drawback of quick diffusion. It also doesn’t provide enough mechanical support for the healing tissue. A solution to this problem would involve embedding the particles inside a wound dressing biomaterial. Introducing antibacterial nanoparticles into woven natural biomaterials as biofabrics would help retain antibacterial activity while providing mechanical support. Here we propose to develop a controlled release antibacterial biofabric produced by electrospinning polymethyl methacrylate (PMMA) as the base material, silk fibroin (SF) as a component to provide mechanical strength, and cationic hyperbranched polyethyleneimine (PEI) to provide antibacterial properties. We propose the antibacterial biofabrics could be a valuable tool to treat chronic wounds as well as coatings for implants (i.e. cardiac pacemakers) that potentially cause infections. Methods SF Regeneration: Silkworm cocoons are boiled to separate fibroin yarns. Silk fibroin is solubilized in LiBr solution followed by dialysis to achieve SF solubility in water. Electrospinning: In order to make biofabrics, PMMA, SF, and/or PEI were combined in dimethylformamide (DMF) and transferred into an electrospinning setup. Polymer solvent was fed at 1.4 ml/hr at 20 kV from 20 cm away from the collector until a thick nanofiber biofabric was developed. Nanoparticle Development: A 4% w/v SF solution was added dropwise to acetone and sonicated for 30. For SF|PEI particles, 1% w/v PEI was added to the same process. The resulting solution was left to stir overnight and the remaining dried particles were crushed with a mortar and pestle and set aside. Inhibition of bacterial growth in liquid medium: Three samples containing 5 mg of SF|PEI were prepared and placed in 5 ml of nutrient broth for an antibacterial assay, alongside samples of 5 mg SF particles in nutrient broth and nutrient broth alone. P. Aeruginosa was seeded into all vials, which were then incubated at 37°C, and the absorbance was measured using a spectrophotometer after 24 hours. Results. Preliminary P. aeruginosa growth assay showed not SF but SF-PEI nanoparticles were 96% effective in inhibiting bacterial growth. Current studies are ongoing in incorporating SF and PEI into PMMA to produce antibacterial biofabrics. The proposed fabrics will not only will provide controlled release of PEI into chronic p. aeruginosa infections but also will provide mechanical support via introduction of SF.