Petra Becker

Cellular investigations on electrochemically deposited calcium phosphate composites

Electrochemically deposited calcium phosphate (CaP) coatings are fast resorbable and existent only during the first period of osseointegration. In the present study, composite coatings with varying solubility (hydroxyapatite (HA), brushite with less HA and monetite (M) with less HA) were prepared and the influence of the degradation and the reprecipitation of CaP on osteoblastic cells were investigated. On the brushite composite coating a new precipitated, finely structured CaP phase was observed during immersion in cell culture medium with or without osteoblastic cells. The surface morphology of monetite and HA coatings were entirely unmodified under the same conditions. So it could be assumed that electrochemically deposited brushite with less HA acts as a precursor for new precipitated CaP. On this surface osteoblastic cells revealed a well-spread morphology with pronounced actin cytoskeleton and demonstrated good proliferation behaviour. Thus we suggest that brushite seems to be especially suitable for coating of implants as a matrix for nucleation and growth of new bone.

Antibiotic Loaded Sol-Gel Derived Calcium Phosphate/Silica Composite for Bone Regeneration

Introduction: The combination of bone repair and local antibiotic therapy is a main topic of the revision surgery of artificial joints (all above hips and knees). Biodegradable artificial bone-like scaffolds combined with a local high concentrated release of antibiotics provide high drug concentrations at the site of infection and could be therefore a strategy for e.g. the cementless joint revision surgery. In connection with the interpretation of chemical results we regarded the physical properties of the calcium phosphate/ silica composite with and without addition of antibiotics. The internal surface of the material and the porosity of the material were detected for the interpretation of the results.