Electrosprayed Calcium Phosphate Coating for Biomedical Purposes

Abstract

The suitability of the electrostatic spray deposition (ESD) technique was studied for biomedical purposes—i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple, inexpensive deposition method for inorganic and organic coatings, it was possible to obtain thin CaP layers with an extremely wide range of chemical and morphological characteristics. Various CaP phases and phase mixtures were deposited, and a broad diversity of coating morphologies was produced by varying deposition parameters related to the ESD-apparatus and/or the precursor solutions. Electrosprayed CaP coatings were shown to be biocompatible with soft tissue, and the osteoconductive nature of electrosprayed CaP coatings was also proven in vivo. Particular interest was given to a unique, reticular coating morphology consisting of a porous network of variable pore size. This specific coating morphology offers the possibility of varying the specific surface area of electrosprayed CaP coatings to a large extent. Consequently, the degradation rate of CaP coatings and the incorporation and subsequent release of biological agents (e.g., growth factors) can be influenced by chemical as well as physical coating properties using the ESD technique. In that way, control over the biological activity of drug-releasing CaP coatings can be improved significantly compared to conventional coating techniques, which lack this chemical and morphological variability.