Therapeutic strategies for bone regeneration: The importance of biomaterials testing in adequate animal models

Abstract

In the past decades, there has been an increasing need for the use of bone grafts in orthopedics, being currently the second most transplanted tissue, surpassed only by blood and its derivates. The biological behavior of a biomaterial is affected by both its chemical composition and its physical proprieties. Regarding the chemical composition, synthetic hydroxyapatite (HA) is one of the most commonly used ceramics, especially due to its osteoconductivity, biocompatibility, and its similarity to bone mineral phase. However, HA is brittle and essentially non-degradable. These limitations encouraged the development of HA forms with tricalcium phosphate, which have a faster resorption rate. Another important bone graft feature is the biomaterial architecture, with the presence of macropore/micropore/interconnective pore. This architecture and the format, shape, or grain size are physical characteristics that could affect biomaterial biological behaviour. Furthermore, attention will be paid to significant "in vivo" testing models for bonegrafting products and its significance in the prograssion to clinical applications of such biomaterials.