A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

Lv Zhanga, Weiwei Liua, Chunguang Yuea, Taihua Zhangb, Pei Lia, Zhanwen Xinga, Yao Chena

a BioManufacturing Research Centre, School of Mechanical and Electric Engineering, Soochow University, 178 East Ganjiang Road, Suzhou 215021, China

b The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100191, China

Received 1 January 2013, Accepted 25 April 2013, Available online 1 May 2013

DOI: 10.1016/j.carbon.2013.04.074

Abstract

Mechanical properties and in vitro biocompatibility of graphene/hydroxyapatite (HA) composite synthesized using spark plasma sintering (SPS) are reported in this study. Raman spectroscopy corroborated that graphene nanosheets (GNSs) survived the harsh processing conditions of the selected SPS processing parameters. A 1.0 wt.% GNS/HA composite exhibits ∼80% improvement in fracture toughness as compared to pure HA. GNS pull-out, grain bridging by GNS, crack bridging and crack deflection are the major toughening mechanisms that resist crack propagation. In vitro osteoblast growth tests illustrate that the added GNSs contribute to the improvement of both osteoblast adhesion and apatite mineralization. Therefore, the GNS/HA composite is expected to be a promising material for load-bearing orthopedic implants.