Biological Characterizations of Hydroxyapatite Crystals

The significant characteristics of a bio-material are its biocompatibility, bioactivity and non-toxic nature. The immediate response from the living cells after introducing the crystalline bio-material into the human body determines its initial compatibility. The purpose of the implant material is to support the function of damaged or replaced tissue. It should be degraded after serving the purpose without causing any side effects, these are non-toxic materials. The crystals which possess the same physicochemical characteristics to that of the natural tissues/organ are generally highly compatible. The hydroxyapatite (HAp) in its crystalline form is similar in crystal structure and their chemical composition to that of the natural bone and hence it is employed in bone tissue repair applications. The methodologies and the mechanism involved in examining the biocompatibility is significant in fabricating crystalline HAp based composites for biomedical applications. The correlation between the physicochemical and biological characteristics of HAp crystals could be understood by performing the biological characterizations at various conditions.