Improvement of water absorption in hydroxyapatite for bone regeneration,

N. M. PIOL; A.OZOLS; S. P. BOEYKENS; INGRID TEN HOEVE; A. B. SARALEGUI

Buenos Aires

Conferencia; 2nd Latin Amirican Conference on Sustainable Development of Energy, Water and Environment Systems; 2020

Facultad de Ingeniería- UBA

The bovine bone, an abundant and low value remains of the meat industry, is subject to physical-chemical processes compatible with environment in order to recycle in higher value products destined to bone substitutes employed in regenerative medicine. Its inorganic phase is hydroxyapatite (HA), (Ca5 (PO4)3(OH), and employed as scaffold in bone tissue reconstruction and regeneration. One of its most relevant properties, which concerns to medical application is its ability to absorb aqueous solutions and blood. However, the involved mechanisms are not clearly determined, and even less, how to improve their efficiency. This work intends to increase the water absorption capacity to improve the HA integration to the autologous bone, accelerate the process of absorption of blood tissue and physiological solutions. This purpose involved the modification HA surfaces by means of different thermal and chemical treatments, leading to their functional modification. It was determined that the optimum bone pyrolysis temperature was 800 ° C for improving absorption. The water absorption was analysed by gravimetric methods and correlated with wettability, measuring contact angle on pressed HA powder in form of tablets. These exhibited a water absorption up to 20% (by weight) after 24 hours of immersion. Also, treatments with phosphoric acid improved significantly wettability. In addition, the effect of polysaccharides led to produce composite beads based on calcium alginate-HA improving absorption up to 70% (by weight). The tested treatments have shown the feasibility of produce bone substitutes with improved water absorption in relation with no modified HA.