Expert News: Investigation of antibacterial and wettability behaviours of plasma-modified PMMA films for application in ophthalmology
Investigation of antibacterial and wettability behaviours of plasma-modified PMMA
This weeks ‘Expert News’ contains interesting research into the plasma surface treatment of PMMA for biodmedical (opthamology) applications. The authors suggest that surface wettability, due to functionalization with oxygen plasma, plays a more important role than surface roughness.
Investigation of antibacterial and wettability behaviours of plasma-modified PMMA films for application in ophthalmology
Courtesy of IOP; Fatemeh Rezaei1, Marzieh Abbasi-Firouzjah1 and Babak Shokri1,2 Published 4 February 2014 • 2014 IOP Publishing Ltd, ,
The main objective of this research is the experimental investigation of the surface properties of polymethyl methacrylate (PMMA) such as wettability and the roughness effect on Escherichia coli (gram negative) cell adhesion. Radio frequency (RF; 13.56 MHz) oxygen plasma was used to enhance the antibacterial and wettability properties of this polymer for biomedical applications, especially ophthalmology. The surface was activated by O2 plasma to produce hydrophilic functional groups.
Samples were treated with various RF powers from 10 to 80 W and different gas flow rates from 20 to 120 sccm. Optical emission spectroscopy was used to monitor the plasma process. The modified surface hydrophilicity, morphology and transparency characteristics were studied by water contact angle measurements, atomic force microscopy and UV–vis spectroscopy, respectively. Based on the contact angle measurements of three liquids, surface free energy variations were investigated.
Moreover, the antibacterial properties were evaluated utilizing the method of plate counting of Escherichia coli. Also, in order to investigate stability of the plasma treatment, an ageing study was carried out by water contact angle measurements repeated in the days after the treatment. For biomedical applications, especially eye lenses, highly efficient antibacterial surfaces with appropriate hydrophilicity and transparency are of great importance. In this study, it is shown that the plasma process is a reliable and convenient method to achieve these purposes.
A significant alteration in the hydrophilicity of a pristine PMMA surface was observed after treatment. Also, our results indicated that the plasma-modified PMMAs exhibit appropriate antibacterial performance. Moreover, surface hydrophilicity and surface charge have more influence on bacterial adhesion rate than surface roughness. UV–vis analysis results do not show a considerable difference for transparency of samples after plasma treatment.
The article can be accessed from the link below: