Screening of photochemically grafted polymer films for compatibility with osteogenic precursor cells

Surfaces of biomaterials often do not have the ideal properties for direct application in vivo. Although titanium and its alloys show a good biocompatibility, in some applications there is still need to improve the osteoblast adhesion to titanium implants. A polymeric surface coating is an ideal solution because the polymer can be adjusted to the needs of the application and can be bound to the surface by the photochemical grafting method. Therefore, 22 different polymers were tested for their compatibility using a murine mesenchymal progenitor cell line and three polymers were identified for which more elaborate investigations are reasonable. It was investigated whether or not the results of the cell culture test can be correlated with, e.g., the wetting properties. Indeed it was found that a contact angle above approx. 45 degrees was necessary for good cell adhesion and proliferation. However, otherwise no clear correlation between the contact angle hysteresis or the functionalities of the polymers and the cell growth was observed.