Studies on new polymeric biomaterials with tunable hydrophilicity, and their possible utility in corneal repair surgery

A well-known complication in corneal repair surgery is (recurrent) rejection of donor corneal tissue, particularly in patients suffering from an auto-immune disease such as rheumatoid arthritis. Down-regulation of their immune system, by means of drugs, is necessary in order to perform an allograft implantation afterwards. The patient may need a temporary prosthetic cornea while the immune system is inactivated. Recently, NeuroPatch (R), a mesh-type polyurethane, was used for this purpose. The material exhibits excellent biocompatibility and allows ingrowth of stromal fibroblasts which deposit matrix material into the pores. A serious drawback of NeuroPatch (R) is its non-transparency, which impairs vision. In this work we attempted to develop an improved biomaterial that combines the advantages of NeuroPatch (R) with optical transparency. Based on previous findings that copolymers of hexaethyleneglycolmethacrylate (HEGMA) and butylmethacrylate (BMA), are transparent and well accepted by human corneal epithelial cells, we studied these materials further in detail. (Bruining et al., Bio-Macromolecules 1 (2000) 418) Copolymerizations were studied by means of H-1 NMR. The influence of the HEGMA content on hydrophilicity, flexibility and resistance to protein adsorption was studied. The results indicate that materials with a HEGMA content of approximately 20 mol% are potentially useful in corneal repair surgery. These biomaterials meet most of the stringent physical and biological requirements. (C) 2001 Elsevier Science Ltd. All rights reserved.