Fabrication And Characterization Of 3D Nano-Hydroxyapatite/Poly (D, L-lactide) Composite Scaffold

Introduction: Comparing with hydroxyapatite (HA), nano-hydroxyapatite has received much more attention due to its excellent biocompatibility. Recent research suggested that the composition, size and morphology of nano-HA resembled natural apatite crystals in bone minerals. There is much increase in protein adsorption and osteoblast adhesion and osteoconductivity on the nano-ceramic materials compared to micro-ceramic materials. In this study, Porous scaffolds which were made of high molecular poly (D, L-lactide) (PDLLA) / hydroxyapatite nanocrystals (nano-HA) were fabricated through solvent-casting and particulate-leaching technique. The morphologies, mechanical properties, biodegradability and biocompatibility of the scaffolds were investigated. Then, 3D dummy human data, CAD and RP technique were combined to construct 3D tissue engineering scaffold. New method to fabricate 3D tissue engineering scaffold was searched.Materials and Methods: Six groups of scaffold were fabricated by using a solvent casting / particulate leaching technique, with PDLLA, micro-HA/PDLLA, and nano-HA/ PDLLA (nano-HA: PDLLA weight ratio 1:9, 1:4, 2:3, 1:1). The phase and morphology of the scaffolds were investigated by using SEM. Cells proliferation was evaluated quantitatively by MTT assay. The interaction between scaffolds and cells were observed by HR-SEM.Results and Discussion: The results showed that nano-HA nanocrystals formed homogeneous dispersion in the PDLLA matrix. The porosity of scaffolds was up to 90%, and macropores and micropores coexisted and interconnected throughout the scaffolds. The tensile modulus for nanocomposites increases with nano-HA loading. The good mechanical properties for nano-HA composites may be due to the homogeneous dispersion of HA nanocrystals in the PDLLA matrix as well as the good interfacial adhesion. Cells grew well after cultured in the scaffold for five days. The morphology of the cells in the last group (nano-HA: PDLLA (w/w) =1:1) was better than others. 3D human data was used to reconstruct 3D cartilage tissue model, 3D scaffold was fabricated with two methods: silica rubber mould were prepared by using SLS RP technique frist, then the scaffold was fabricated by traditional method; after designed reasonable structure, 3D scaffold was constructed by SLS technique.Conclusion: In the study, we fabricated a nanocomposite porous scaffold, and this kind of scaffold showed outstanding biocompatibility and other biological properties. Tissue engineering scaffold could be constructed exactly, rapidly and conveniently by using RP technique. In conclusion, nano-HA/PDLLA porous scaffold and RP technique have a promising application in cartilage tissue engineering.