The mechanism by which bioactive coatings enhance the integration of implants with the host is not clearly understood. Recent studies have shown that this may be related to the ability of these calcium phosphate coatings to provide proper amounts of Ca2+ and (PO4)3 ions at the interface, and the ability to adsorb cell adhesion molecules like fibronectin. The applicants have developed an electrodeposition-based coating process that can be used to prepare coatings (brushite) whose solubility in simulated body fluids (SBF) can be controlled, and which provides Ca2+ and (PO4)3 ions at concentrations similar to that found physiologically. The brushite, when exposed to SBF, undergoes a transformation to a crystalline carbonated hydroxyapatite (HA), which is close to natural bone and tooth enamel in composition. It is indicated that they can securely anchor unaltered, highly crystalline hydroxyapatite on the surfaces of implant materials like titanium with about 50 to 65% surface coverage. The remaining surface area then can be covered with the more soluble calcium phosphate ceramic (brushite), that transitions to crystalline HA when exposed to SBF. They have monitored and measured the transformation and the interaction of brushite to HA using x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy. In the present study, the applicant now proposes to evaluate these coatings in situ, in SBF, using Fourier transform infrared with attenuated total internal reflection techniques (FTIR/ATR). Information about rates of dissolution, chemical transformation and the interaction of albumin and fibronectin will be obtained in real time using FTIR/ATR. This study is intended to help establish a quantitative relationship between the composition and the physical state of bioceramics and the properties of these bioceramics in the physiological environment.
| Eming, Sabine A; Krieg, Thomas; Davidson, Jeffrey M (2007) Inflammation in wound repair: molecular and cellular mechanisms. J Invest Dermatol 127:514-25 |
| Eming, Sabine A; Werner, Sabine; Bugnon, Philippe et al. (2007) Accelerated wound closure in mice deficient for interleukin-10. Am J Pathol 170:188-202 |
