Polymer, Vol.38, No.15, 3869-3874, 1997
Water-Uptake and Protein Release Characteristics of a New Methacrylate-Based Polymer System
A novel polymer system comprising poly(ethyl methacrylate) (PEMA) powder gelled with hydroxyethyl-methacrylate (HEMA), n-butylmethacrylate (nBM) monomer mixtures has been produced. The monomers were combined in different ratios to vary the relative hydrophobicity of the system. Surface and bulk properties of this copolymer system were investigated. Surfaces were relatively featureless with little variation due to composition. Contact angles ranged from 76 to 83 degrees. Equilibrium water content of the polymers was directly related to the mole fraction of HEMA content. The uptake of water in the earlier stages was proportional to t(1/2), consistent with a diffusion process; the slope of this plot enabled diffusion coefficients to be measured. maximum equilibrium water content was 16%. Water uptake was reduced in phosphate-buffered saline, but addition of bovine serum albumin did not affect water uptake. Desorption was also linear on a t(1/2) plot in the early stages. There was a direct relationship between water uptake and loss. The polymer system was capable of releasing albumin; the amount of albumin released was inversely related to the HEMA content of the system. The relationship of the properties of the polymer system to biological interactions and potential applications are discussed.
Keywords:HETEROCYCLIC METHACRYLATES;CLINICAL-APPLICATIONS;GROWTH-HORMONE;MECHANICAL-PROPERTIES;BIOLOGICAL RESPONSE;BONE-CEMENT;SURFACES;FIBRONECTIN;ADHESION