Porous bioceramic and biomaterial for bone implants

This dissertation describes the introduction of interconnected porosity to a calcium polyphosphate ceramic material designed for bone substitute, as well as the synthesis of various controlled release vehicles for carrying growth factors to work with the bioceramic. The surface of the bioceramic was also modified in an attempt to reduce the acidity problem. The interconnected porosity in the making of highly porous calcium phosphate bioceramic was introduced with volatile chemicals and the physical properties of the modified porous ceramic were investigated with various methods, including porosimetry, compression strength testing, digital image analysis, and elemental analysis. Biopolymer from gelatin was chemically cross-linked to hydrophobic pendent groups, such as palmitic acid N-hydroxysuccinimide or deoxycholic acid, to make polymeric microcapsules. The synthesis, methods of making microcapsules and release rates of a model protein, albumin, are discussed. New inorganic calcium phosphate cements were also investigated for their use in carrying growth factors as well as suitability as bone substitutes for weight-bearing or non-weight-bearing applications. To eliminate the acidity problem of the calcium polyphosphate ceramic biomaterial synthesized in our laboratory, various methods, physical or chemical, were investigated. Although the attempts did not provide results as anticipated, a proposed explanation for the past successful animal trials with this acidic calcium polyphosphate bioceramic was deduced from the results of the experiments.