Antimicrobial and Biofilm Eradication Potential of Amine-Functionalized Polymeric Micelles

Abstract

Antimicrobial resistance has been a growing concern of the 21st century affecting a major portion of the globe. It has further delved into playing a role in formation of biofilms in the process of chronic wound healing. Studies have shown that the combination of synthetic and natural antibiotics formulated with nano-technology can be an innovative solution in tackling bacterial growth. This study aimed at assessing the antimicrobial potential of caffeic acid, gallic acid and diclofenac (repurposed) antimicrobial drug. The study investigated the anti-biofilm potential of free diclofenac, diclofenac loaded amine-functionalized polymeric micelle and unloaded amine-functionalized polymeric micelle. Broth Microdilution MIC assay was performed to assess IC50 and MIC values. The Biofilm Eradication assay was conducted to assess the antibiofilm potential of diclofenac loaded and unloaded amine-functionalized polymeric micelles. UV spectrophotometer was used to find the drug loading of micelles while GraphPad prism was used for statistical analysis. It was found that caffeic acid had an IC50 of 1000ug/ml while gallic acid had an 1C50 of 1250ug/ml. Free diclofenac showed potent antibacterial action with MIC at 155ug/ml. The highest antibacterial efficacy was noted by unloaded amine-functionalized polymeric micelle with MIC at 148ug/ml. Further, caffeic acid and gallic acid showed no synergy with diclofenac in improving antibacterial efficacy. To conclude, in staphylococcus aureus biofilm, the strongest antibacterial effect was observed by unloaded aminefunctionalized polymeric micelle. The positive charge of the amine groups, and their direct interaction with the negatively charged bacterial cell wall led highest penetration and cell lysis.