Abstract
Purpose :
Microbial keratitis (MK), the microbial infection of the cornea, is a leading cause of ocular morbidity and blindness globally. Contact lens wear, ocular inserts, ocular bandages etc. constitutes the major risk factor for MK. To overcome these microbials-associated complications, one approach is to develop biocompatible, optically transpartent and inherently antimicrobial soft materials that can be used to design safe ocular devices.
Methods :
In the present work, we are reporting the laccase-catalysed oxidative polymerization of 14 catecholamines/catechols for the preparation of optically transparent, mechanically robust, thermally stable, broad spectrum antimicrobial polyvinyl alcohol films. UV-visible spectroscopy, Fourier-transform infrared spectroscopy, atomic force microscopy, thermogravimetric analysis, stress-strain studies are carried out to understand the optical, surface and bulk properties of the films. Antimicrobial evaluation has been carried out for the films using both Kirby-Bauer disc diffusion method as well as using microbroth dilution method in accordance with Clinical and Laboratory Standards Institute (CLSI) protocol.
Results :
Among all the investigated compounds, adrenalin (AD), pyrogallol (PG) and hydroquinone (HQ) are identified as the important phenolic compounds to generate efficient antimicrobial PVA films with optimized optical, surface and bulk properties. Interestingly, PVA films reinforced with oxidized/polymerized products of pyrogallol and adrenalin display potent antimicrobial activity against pathogenic Gram-positive, Gram-negative and yeast strains. Whereas hydroquinone reinforced PVA films display excellent antimicrobial properties against Gram-positive bacteria only.
Conclusions :
Owing to the their optical transparency, oxygen permeability and high thermal stability combined with antimicrobial properties, the reinforced films could play a promising role in designing antimicrobial ophthalmic devices such as contact lens wares, ocular inserts, ocular bandages and intraocular lenses.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.