Evaluation of the Cytotoxic effects of various monomers In vitro also their effects on Apoptosis and GFAP immunolocalization in rat spinal cord In vivo

Abstract

Biomaterials are mostly polymers made by monomers, and are used in artificial organ production in contemporary medicine. They are prepared by the polimerization reaction of certain monomers. The aim of the present study was to investigate whether acrylamide, methacrylamide, N-isopropylacrylamid, acrylic acid, 2-hydroxyethyl methacrylat, 1-vinyl-2-pyrrolidone and ethylene glycol had cytotoxic effects and induce apoptosis or not in spinal cord. Immunolocalization of glial fibrillary acidic protein (GFAP) was also determined, and it was evaluated by using semi-quantitative morphometrical techniques. The cellular process of apoptosis is an important component of tissue and organ development as well as the natural response to disease and injury. Therefore the positive immunohistochemical staining for apoptosis was also examined by TUNEL staining technique. Following the intramuscular injection of aqueous monomer solutions that are prepared in certain concentration, appropriate tissue samples obtained at certain time intervals were fixed in 10% buffered neutral formaline. The cytotoxicity of monomers on cultured fibroblastic cell lines was examined in vitro. Acrylic acid had the most cytotoxic effect when compared to the methacrylamide and the ethylene glycol groups. GFAP immunoreactivity was found to be rather stronger in the methacrylamide than the other monomers application groups. TUNEL positive cell were observed in the methacrylamide, acrylic acid, N-vynil pyrrolidine, acrylamide, N-isopropylacrilamid and 2-hydroxyethyl metacrylad application groups than the other groups. In conclusion, while some monomers used in biomaterial production seemed not to affect the cell viability and GFAP immunoreactivity, some other monomers had adverse effects on those features. This in turn may contribute to the pathological changes associated to the monomer type.