Author: Jade Fong
Fong, Jade, 2024 Innovative Gallium Silver-Glutathione-Silk Sericin Nanofibers by Electrospinning: Promoting Tissue Regeneration and Antibacterial Efficacy in Diabetic Wound Care, Flinders University, College of Medicine and Public Health
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Chronic diabetic wounds, marked by delayed healing and increased susceptibility to infections, present significant challenges in clinical care. The frequent antibiotics usage for these infections has accelerated antimicrobial resistance, complicating treatment strategies and hindering patient recovery. In this project, we will investigate advanced electrospun nanofiber scaffolds designed to enhance tissue regeneration while providing effective infection control. These scaffolds incorporate bioactive particles—including silk sericin, gallium, silver, and glutathione—within a poly(caprolactone) (PCL) matrix, offering a multifunctional platform for wound management. A series of formulations were synthesised: silk sericin particles (SS Ps), gallium-silk (Ga-SS Ps), glutathione-silk (GSH-SS Ps), gallium-glutathione-silk (Ga-GSH-SS Ps), gallium-silver-silk (GaAg-SS Ps), and gallium-silver-glutathione-silk (GaAg-GSH-SS Ps). These bioactive particles were encapsulated within the PCL matrix using optimised electrospinning techniques. Structural and functional characterisations of the scaffolds revealed key insights. Notably, a reduction in pH from 6.33 in the SS solution to 5.03 in the GaAg-GSH- SS solution suggests substantial chemical interactions among the components, indicating modifications in the ionic environment and proton activity within the scaffold matrix. SEM analysis confirmed the successful encapsulation of gallium-silver by silk sericin, with GaAg- GSH-SS particles displaying an average size of 400 nm. ATR-IR spectroscopy further validated the integration of these nanocomposites, revealing consistent spectral peaks in the amide I region (1600–1690 cm−1) and the amide II region (1480–1575 cm−1), indicative of protein incorporation within the scaffold. Antibacterial assessments demonstrated that GaAg-GSH-SS particles effectively inhibited both P. aeruginosa and S. aureus at concentrations of 0.18 mg (Ga)/mL + 0.016 mg (Ag)/mL and 0.36 mg (Ga)/mL + 0.032 mg (Ag)/mL, respectively, underscoring their potent antimicrobial efficacy. The antibacterial performance of the nanofiber scaffold was further evidenced by a marked reduction in bacterial counts, with S. aureus achieving CFU levels as low as 2.6 × 108 CFU/mL. Complementary biocompatibility tests confirmed that the scaffolds support HaCaT cell viability, with cell survival rates increasing from 90% to 92% between 24 and 72 hours, demonstrating their ability to foster cellular health and proliferation. In summary, the electrospun GaAg-GSH-SS nanofiber scaffolds exhibit robust antimicrobial activity, effective biocompatibility with keratinocytes, and controlled delivery of bioactive agents. These findings highlight the potential of these multifunctional scaffolds as innovative wound dressings for chronic diabetic wounds, offering a promising solution to accelerate healing while reducing infection risks and improving patient outcomes.
Keywords: chronic wound, electrospun nanofiber, electrospinning, gallium liquid metal, silver nanoparticle, antibacterial, wound healing
Subject: Medical Biotechnology thesis
Thesis type: Masters
Completed: 2024
School: College of Medicine and Public Health
Supervisor: Vi Khanh Truong