Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility

Abstract

Bo Qiao,1 Jidong Li,2 Qingmao Zhu,1 Shuquan Guo,1 Xiaotong Qi,1 Weichao Li,1 Jun Wu,1 Yang Liu,3 Dianming Jiang1 1Department of Orthopaedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 2Research Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu, 3Department of Orthopaedics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China Abstract: An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. Keywords: nano-hydroxyapatite, polyamide, glass fiber, biomechanics, biocompatibility