Exploration of Nanotherapeutic Intervention for Biofilm Disruption of Enterococcus Species

Abstract

Bacterial infections occurrence has increased dramatically due to microbial biofilm formation which roots for poor drug penetration causing antibiotic resistance which has made site specific sustained drug delivery the suitable option. Our first approach was to prepare Ciprofloxacin (CPX) loaded water in oil nanoemulsion (w/o NE) and evaluate against oral biofilm produced by Enterococcus faecalis (E. faecalis). CPX-NE was prepared by ultrasonication technique using Oleic acid as oil phase, Span 80 as surfactant and Transcutol P as co-surfactant. Rheological parameters confirmed optimum values for w/o type NE and indicated isotropic nature of NE. Particle size (72.19 ± 1.68 nm), PDI (0.142 ± 0.02) and zeta potential (-28 mV) showed narrow size distribution and electrostatically stabilized NE. Morphology depicted by fluorescence microscope image. In-vitro (IVR) drug release showed initial burst effect followed by sustained release for 48 h, followed Fick s law of diffusion. Minimum biofilm inhibitory and eradication concentration (MBIC/MBEC) was determined to compare CPX-NE with CPX plane drug solution (CPX-PS) for their efficacy. CPX-NE demonstrated significant inhibitory and eradication effect compared to CPX-PS. Our second approach entails the fabrication of CPX loaded nanofibers using polyvinyl alcohol (PVA) and poly(meth) methacrylate (PMMA) employing electrospinning method to form CPX nanofibers (PVA:PMMA:CPX). These nanofibers were subjected to characterizations such as Fourier-Transform Infra-red Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) Atomic Force Microscopy (AFM) and IVR study. SEM and AFM images revealed average nanofiber diameter of 243±80 nm with smooth surface morphology. DSC, FT-IR and XRD graphs cumulatively confirmed drug encapsulation and drug-polymer compatibility. IVR results demonstrated sustained release of CPX for 22 days showing Hixon Crowell release kinetics and two-stage des