Effect of bamboo fiber on the degradation behavior and in vitro cytocompatibility of the nano-hydroxyapatite/poly(lactide-co-glycolide) (n-HA/PLGA) composite

To obtain an ideal nano-hydroxyapatite/poly(lactide-co-glycolide) (n-HA/PLGA) composite for bone materials, bamboo fiber (BF) was selected to reinforce n-HA/PLGA. The effects of different loadings and surface modification methods for BF on in vitro degradation behavior and cell viability of n-HA/PLGA were evaluated. In vitro degradation was tested in a simulated body fluid while cell viability experiment was carried out using human osteoblast-like cells (MG-63). The changes of tensile strength, water absorption, surface microstructure and thermal properties during the soaking were investigated by means of electromechanical universal tester, scanning electron microscope and differential scanning calorimeter. Moreover, the cell attachment and proliferation of samples were evaluated by fluorescence microscope, inverted microscope and MTT method. The results showed that the degradation started from the interface between BF and n-HA/PLGA matrix, and the degradation rate of the BF/n-HA/PLGA composite was accelerated with the increasing BF amount. Fortunately, the surface-modified BF could improve the interface compatibility and display more suitable degradation rate. In addition, the in vitro cell incubating experimental results reflected that BF was nontoxic and had no side effect on cell attachment and proliferation. Especially, BF/n-HA/PLGA composite with 5% surface-modified BF had better cytocompatibility. The study suggested that the surface-modified BF had a great potential in developing BF/n-HA/PLGA composite used as bone materials in the future. Graphical abstract Bamboo fiber (BF) played an important role in improving the mechanical property of n-HA/PLGA composite. Here, the effect of different contents and surface modification methods for BF on in vitro degradation behavior and cell viability of n-HA/PLGA composite was comprehensively study by the experiments of soaking in simulated body fluid (SBF) and incubating with human osteoblast-like cells (MG-63). The results showed that the incorporation of BF accelerated the degradation of the BF/n-HA/PLGA composite, and the composite with higher BF content had faster degradation. Fortunately, the surface-modified BF made the composite has more suitable degradation than the unmodified BF. Moreover, in vitro cell incubating experiment results reflected that BF was nontoxic and exhibited no side effects on cell attachment and proliferation of the BF/n-HA/PLGA composite. Especially, BF/n-HA/PLGA composite with 5