Development of a novel antimicrobial and drug delivery strategy to combat biofilm

Abstract

Biofilms are structured communities of microorganisms that are encased within a self-produced matrix of extracellular polymeric substances (EPS). They contribute to the persistence of chronic diseases and pose challenges for effective antimicrobial treatment due to their tolerance to harsh conditions and resistance to traditional therapies. This study aimed to evaluate the antimicrobial and anti-biofilm properties of 1-alkyl-3-methyl imidazolium chloride ionic liquids (ILs) against common bacterial strains associated with oral diseases and chronic wounds: Porphyromonas gingivalis, Staphylococcus aureus, and Pseudomonas aeruginosa. Four different alkyl chain lengths (2, 4, 6, and 10) of ILs were investigated. Initially, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ILs against planktonic bacteria were determined. Fluorescent microscopy and flow cytometry were used to visualise and further assess the effectiveness of ILs. Transmission electron microscopy (TEM) was employed to study morphological changes in planktonic bacteria after exposure to elevated IL concentrations for 24 hours, with a comparison to a control substance, 75% ethanol. Subsequently, appropriate IL concentrations, depicted by the data, were evaluated for their impact on biofilm inhibition and eradication. Biomass determination using crystal violet staining, viability assessment using the XTT assay, and visualisation of biofilm effects through confocal microscopy were employed as evaluation methods. Upon verifying the antimicrobial potential, the most promising 1-alkyl-3-methyl imidazolium chloride compound was further explored for potential incorporation into a microneedle system for therapeutic delivery. This research contributes to the development of effective strategies against biofilm related infections by investigating the antimicrobial and anti-biofilm properties of ILs. The findings highlight the potential of ILs as therapeutic agents to combat biofilm associated diseases and address the challenges posed by bacterial resistance. Additionally, the study explores the feasibility of incorporating ILs into a microneedle system for targeted delivery, providing a promising avenue for future therapeutic applications.