Effect of silicon rubber crosslink density on fibroblast cell behavior in vitro

In this study, samples of poly(dimethylsiloxane) (PDMS) with different crosslink densities were prepared in order to produce samples with different crosslink density and, subsequently, different molecular mobilities. Crosslink density and chain mobility changes in PDMS networks were determined using differential scanning calorimetery and dynamic mechanical thermal analysis, respectively. Surface roughness was studied by scanning electron microscopy (SEM). To evaluate biocompatibility, mouse fibroblast L-929 cells were cultured onto different samples, and their numbers and growth behaviors were investigated by optical microscopy. The results showed that crosslink density and, consequently, molecular mobility cause changes in cell behavior. Moreover, we found that there is an optimum molecular mobility for PDMS at which the number and the surface areas of cells show the best cell attachment and proliferation.