Enhancement effect of cell adhesion on titanium surface using phosphonated low-molecular-weight chitosan derivative

Abstract

For improving cell adhesion on titanium surface, phosphonated low-molecular-weight chitosan (P-LMC) was prepared by introducing a phosphonate group of 4-phosphonobutyric acid to low-molecular-weight chitosan (3,000 < MW < 10,000). The phosphonate group of P-LMC was identified by P-31 NMR. At about 30 ppm from external standard, there was a specific peak derived from phosphonate group. X-Ray Photoelectron Spectroscopy (XPS) and water contact angle were carried out for characterization of titanium surface treated with P-LMC. From these results, P-LMC coated on titanium surface was remained on that in spite of washing and P-LMC made titanium surface more hydrophilic. The biocompatibility of P-LMC was demonstrated through a cytotoxicity test using the C2C12 cell line because P-LMC should have no cytotoxicity for applying to dental implant materials. As a result, P-LMC was biocompatible to use as coating material of titanium. Improvement of cell adhesion on titanium surface treated with P-LMC was observed by microscopy, and the number of attached cells was counted using a hemocytometer. Titanium surface coated with P-LMC showed improved cell adhesion for 12 h. These results demonstrate that P-LMC is biocompatible and titanium surface treated with P-LMC has positive effects on cell adhesion. Therefore, P-LMC is a useful material that can be applied for titanium coating to enhance cell adhesion and osseointegration.