Preparation and characterization of amine functional nano-hydroxyapatite/chitosan bionanocomposite for bone tissue engineering applications

In this study, three different types of scaffolds including a uniquely modified composite scaffold - namely chitosan (CTS), nano-hydroxyapatite/chitosan composite (CTS + nHAP), and amine group (NH2) modified nano-hydroxyapatite/chitosan composite (CTS + nHAP-NH2) scaffolds - were synthesized for bone tissue engineering (BTE) purposes. As results of the study, it was found that all scaffold types were biodegradable with CTS and CTS + nHAP scaffolds losing up to 15% of their initial weight, while the CTS + nHAP-NH2 scaffold showing 10% of weight loss after six weeks of lysozyme treatment. In addition, all three types of scaffolds were shown to be biocompatible, and amongst them CTS + nHAP-NH2 scaffolds supported the most cell proliferation in WST-1 assay and expressed the least and acceptable level of cytotoxicity in lactate dehydrogenase (LDH) test for human bone mesenchymal stem cells (hBM-MSCs). Finally, during osteoinductivity assessment, CTS + nHAP-NH2 nearly tripled initial alkaline phosphatase (ALP) activity when whereas both CTS and CTS + nHAP scaffolds only doubled. These results indicate that all synthesized scaffold types under investigation have certain potential to be used in bone tissue engineering approaches with CTS + nHAP-NH2 scaffold being the most promising and applicable one. In the future, we plan to intensify our studies on osteogenic differentiation on our scaffolds on a detailed molecular level and to include in vivo studies for pre-clinical purposes.