TITLE:
The Effect of Direct Gas Fluorination on Medical Grade Poly(methyl methacrylate)
AUTHORS:
Baljit K. Ghatora, Stephen J. Barton, Peter J. S. Foot, Philip Miller Tate
KEYWORDS:
Poly(methyl methacrylate) (PMMA), Surface Fluorination, In Vitro Studies, Simulated Aqueous Humour Solution (SAHS), Medical Polymers
JOURNAL NAME:
Open Journal of Organic Polymer Materials,
Vol.4 No.4,
October
20,
2014
ABSTRACT: Medical-grade poly(methyl methacrylate) (PMMA) is extensively employed in the fabrication of a variety of medical implants, including intraocular lenses (IOLs). However, a postoperative complication that leads to the failure of the implanted intraocular lenses has been recently identified. This process, termed calcification, occurs when calcium-containing deposits accumulate on the surface of the IOL. In this study direct gas fluorination was used to modify the surface of PMMA in an attempt to increase the service lifetime of the material in optical applications. PMMA discs exposed to a 20% fluorine/nitrogen gas mixture for 24 h were compared with untreated PMMA discs serving as control samples. Over time, both surface-fluorinated and untreated PMMA samples immersed in a simulated aqueous humour solution (SAHS) (pH 7.4, 35°C) were used to carry out in vitro studies. Attenuated total refractive Infrared spectroscopy (ATR-IR) Scanning electron microscopy (SEM), coupled with Energy dispersive X-ray analysis (EDX), showed that calcium-containing surface deposits were less abundant on surface-fluorinated PMMA compared with the control samples, indicating that the fluorinated surface was acting as a barrier to the deposits. Gravimetric analysis data showed that the decreased rate of diffusion compared with that of a control sample was due to the fluorinated surface.