[Striated muscle microvascular response to implants with sol-gel calcium phosphate coating. A comparative in vivo...

Local microvascular perfusion plays an important role in reparative processes and the pathogenesis of infection. The impairment of skeletal muscle microcirculation by a biomaterial may therefore have profound consequences. The aim of our study was to determine whether the biological acceptance of the widely utilised implant material stainless steel can be improved by a coating of sol-gel calcium phosphate.

Using the hamster dorsal skinfold chamber preparation and intravital microscopy, we quantified nutritive perfusion and leukocyte-endothelium interaction in skeletal muscle after implantation of sol-gel calcium phosphate-coated stainless steel- and commercial pure titanium implants, and compared these results to those obtained with uncoated stainless steel and titanium.

Within the first 24 h after implantation, animals with calcium phosphate coated stainless steel showed a significantly lower inflammatory response than did those with an uncoated stainless steel implant. After 24 h the quantified microcirculatory parameters deteriorated for animals with a calcium phosphate-coated stainless steel plate, indicating that, for as yet unknown reasons, the shielding mechanism of the calcium phosphate seems to deteriorate. Although not as inert as pure titanium, we found a relatively low inflammatory response for calcium phosphate coated titanium over the whole observation period, suggesting that the coating as such is well tolerated by the skeletal muscle microcirculation.

Our in vivo results suggest that the biological acceptance of a conventional stainless steel implant can be improved over a short term by a sol-gel coating of calcium phosphate. Concerning tolerance by the local vascular system, commercially pure titanium currently remains unsurpassed.