Antibacterial Efficiency of Quaternary Ammonium Silane-Coated Shoe Insoles Using the Sol-Gel Technique

Objective: Foot microbial infections are a common concern, particularly among individuals with diabetes, athletes, and those with compromised immune systems. Traditional methods for managing these infections include topical treatments and oral antibiotics. Diabetes mellitus patients, sportsmen and women, postoperative foot/ankle patients, and people who wear shoes for longer periods require extra attention due to the increased risk of microbial infection. The microenvironment of footwear, including its humidity, temperature, and aeration, supports the growth of pathogenic or opportunistic microorganisms. However, these approaches can not provide continuous protection against emerging infectious diseases and can not prevent antibiotic-resistant infections. Antimicrobial-incorporated shoe insoles present a novel and promising solution for preventing and managing foot microbial infections through their sustained release, which ensures long-term antimicrobial activity and reduces the risk of infection recurrence. These insoles are embedded with antimicrobial agents, like silver nanoparticles, copper ions, or organic antimicrobial compounds that provide continuous protection against a broad spectrum of microorganisms (bacteria, fungi and viruses). The occurrence of common foot infections like athlete’s foot, fungal nail infections, and bacterial infections associated with diabetic foot ulcers can also be mitigated.Materials and Methods: This study was conducted to examine the possibility and efficacy of the application of antibacterial quaternary ammonium silane compound-treated shoe insole materials in the mitigation of foot microbial infections. EN ISO 20645:2004, AATCC 147-2019, ISO 16187:2013, and fluorescence staining (CTC/DAPI) test methods were used in this study to analyze the antibacterial efficacy of the tested insole foam against Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus.Results: Antimic®[(3-(trimethoxysilyl)-propyl, cocodimethylammonium chloride] compound-incorporated shoe insoles resulted in total bacteria reduction (92-96%) after 24-hour contact time, without triggering a viable but non-culturable (VBNC) state in the tested bacteria.Conclusion: Antimic® compound-incorporated shoe insoles represent a significant advancement in the prevention and management of foot microbial infections, providing a continuous, effective, and convenient method for maintaining good foot health.