Evaluation of Cellular Responses to Growth Factors and Collagen‐treated Materials by RNA In‐situ Hybridization

Abstract

Implantation of biomaterials or surface-modified capsules such as drug-delivery systems into the body induces various cellular responses around the implanted sites. The interaction between various cells and biomaterials has been investigated by analysing cell growth rates, cell morphologies and various cellular responses such as protein secretion. The RNA in-situ hybridization technique was originally developed to measure gene expressions in multicellular organisms such as tissue sections. We have modified and applied this procedure for in-vitro cultured cells to evaluate the biocompatibility of biomaterials. As a model study, we have shown that cellular responses to surface-modified materials, such as collagen-type-I-treated materials with or without a cytokine, can be evaluated by this RNA in-situ hybridization technique. This work suggested that the expression of a marker gene (T gene) was regulated by several parameters, including modifications of cell-culture substrate surfaces and the presence of soluble proteins (cytokines) in the culture medium. These results suggest that cellular responses to biomaterials with or without cytokines can be examined by parameters obtained by RNA in-situ hybridization.