Ultra-high molecular weight polyethylene bioactive composites with carbonated hydroxyapatite

• Published in: Journal of the mechanical behavior of biomedical materials 2020-10, Vol.110, p.103938-103938, Article 103938
• Main Authors: Senra, Mônica Rufino, Vieira Marques, Maria de Fátima, de Holanda Saboya Souza, Diego
• Format: Article
• Language: English
• Subjects: Bone replacement; Carbonated hydroxyapatite; Durapatite; Friction; Materials Testing; Mineralized collagen matrices; Molecular Weight; Polyethylenes; UHMWPE
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2020.103938

To develop an orthopedic material for bone substitution, the substitute material must mimic living tissue from an anatomical and physiological point of view. The high wear and impact resistance besides the low friction coefficient, make ultra-high molecular weight polyethylene (UHMWPE) a suitable material to be used in orthopedic applications. However, UHMWPE is a bioinert material, not providing a proper interaction with the bone tissue surrounding to the implant. One way to mitigate this issue is improving UHMWPE bioactivity. This can be done by adding bioactive fillers in the polymeric matrix. In this work, UHMWPE composites were prepared by twin-screw extrusion. The fillers used were carbonated hydroxyapatite (CHA) and hybrids formed by precipitating CHA in collagens (hydrolyzed and type II). The results show that the fillers used caused a slight reduction in UHMWPE crystallinity degree, while both crystallization and melting temperatures remained almost unchanged. Dynamic-mechanical thermal analysis indicated a weak adhesion between filler and polymeric matrix, which is good from the biological point of view since the bioactive filler surface will be available to apatite deposition. The obtained materials exhibited good mechanical properties and in vitro bioactivity assay showed that all of the prepared materials are bioactive. [Display omitted] •UHMWPE bioactive composites were obtained by twin-screw extrusion.•Carbonated hydroxyapatite and its hybrids with collagens are the fillers used.•The mechanical and thermal behaviors of the composites were studied.•The addition of collagen into the polymeric matrix helped fillers dispersion.•All materials are bioactive as verified by the in vitro bioactivity assay.