Preparation and properties of biomimetic hydroxyapatite-based nanocomposite utilizing bamboo fiber

Biomass fiber is currently one of the most attractive research pursuits in the biomaterials field. In this study, bamboo fiber (BF) was firstly chosen to replace other polymers to prepare nano-hydroxyapatite (n-HA)-based nanocomposite, and the effects of different states, treatments methods, the addition amounts and addition methods of BF on the formation of n-HA on BF fiber and the corresponding n-HA/BF composites were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, electromechanical universal tester, in vitro soaking in simulated body fluid and in vitro cell culture experiment. Results demonstrated that n-HA with the irregular morphology was attached on BF fibers, and it could be hybridized with BF to form n-HA/BF composite, however, there was subtle difference of the crystallinity, size and formed amount of n-HA attached on the different BF fibers, which brought about different surface properties of the n-HA/BF composites. And 30 wt% BF endowed the n-HA/BF composite with the best mechanical properties, whose was by far higher than that of pure n-HA. In addition, in vitro simulated body fluids soaking results indicated that n-HA/BF composites displayed different water absorption rates, and all n-HA/BF composites could promote the apatite deposit. Meanwhile, the n-HA/BF composites exhibited good cytocompatibility, including attachment and proliferation. All results proved that single BF polymer could be used to act as the organic matrix to prepare n-HA-based nanocomposite by replacing collagen component of natural bone, and the alkali treated and undissolved BF with 30 wt% addition amount by precipitated method was the best appropriate condition to prepare the ideal n-HA/BF composite. Consequently, the study would open up a new application of natural BF in the biomedical field. In this manuscript, bamboo fiber (BF) was firstly chosen to replace other polymers to prepare nano-hydroxyapatite (n-HA)-based nanocomposite, and the effects of different states, treatments methods, the addition amounts and addition methods of BF on the formation of n-HA were investigated. Results demonstrated that n-HA with the irregular morphology was attached onto BF and hybridized with BF, and n-HA possessed different crystallinity and size, which brought about different properties of the n-HA/BF composites. Overall, the alkali treated and undissolved BF with 30 wt% addition amount by co-precipitated method was the best appropriate condition to prepare the ideal n-HA/BF composite, which had a great potential to be used as bone materials. The study proved that single BF could replace other polymers to develop n-HA-based nanocomposite used as bone materials, which would open up a new idea to utilize BF in biomedical field. SEM micrographs of samples. (a) Pure n-HA, (b) alkali/undissolved/precipitated, (c) unalkali/undissolved/precipitated, (d) alkali/dissolved/co-precipitated, (e) alkali/undissolved/blended, (f) acid/undissolved/precipitated, (A) 20%BF/n-HA, (B) 30%BF/n-HA, (C) 40%BF/n-HA