Evaluation of selective laser sintered polyamide/hydroxyapatite composite compositions in vitro and in vivo

Objective: To study the suitability of the developed polyamide/hydroxyapatite (PA/HA) composite orthopaedic scaffold in vitro and in vivo. Methods:  The fabricated scaffolds were seeded with human osteoblast-like cell line (MG 63) and tested for its viability & cytotoxicity, proliferation and calcium mineralization through MTT assay, ALP assay and Alizarin red S staining respectively. Finally, the scaffolds were implanted in non-immunocompromised male wistar rats subcutaneously and pathological tests were carried out. Results: The results of in vitro studies indicate that PA/HA (90:10) composite was non-cytotoxic and supported calcium mineralization relatively better than the other compositions of PA/HA.  From the Hematoxylin & Eosin staining, inflammation was observed in the tissues surrounding the scaffold 7 weeks post implantation in rats. However, the scaffolds were found to be incorporated into the subcutaneous tissue at the end of one year without any rejection. Conclusion: PA/HA (90:10) composite scaffold fabricated using SLS is biocompatible when tested in rats, and could more likely be used for orthopedic applications.