Fabrication of macroporous apatite bone cements for non ‐load bearing orthopedic applications

AbstractCalcium deficient hydroxyapatite (CDHA)-based apatite forming bone cements are well known for their bioactivity and bioresorbability. The formulation of CDHA-based cements with improved macroporosity, injectability, and resorbability has been investigated. The solid phase consists of nanocrystalline hydroxyapatite (HA) and tricalcium phosphate ( β-TCP). The liquid phase is diluted acetic acid with disodium hydrogen phosphate as binding accelerator along with gelatin and chitosan to improve the injectability. A porogen agent either mannitol (as solid porogen) or polysorbate (as liquid porogen) is also used to improve the porosity. All combi ned in fine-tuned composition results in optimal bone cements. The cement sets within the clinically preferred setting time (≤20 min) and injectability (>70%) and also stable at physiological pH (i.e., ~7.3 –7.4). The XRD and FT-IR analysis confirmed the formation of CDHA phase on day 7 when the after-set cement immersed under phosphate buffer solution (PBS) at physiological conditions. The cements were found to have acceptable compressive strength for trabecular bone substitute. The cements were mac roporous in nature with average pore size between 50 and 150 μm and were interconnected as confirmed by SEM, micro-CT and MIP analysis. The prepared cements are degradable up to 22% and 19% in simulated body fluid and PBS respectively within 10 weeks of immersion at physiological conditions. Th e cements exhibit higher vi...
Source: Journal of Biomedical Materials Research Part B: Applied Biomaterials - Category: Materials Science Authors: Tags: RESEARCH ARTICLE Source Type: research