3D Printed Hydroxyapatite Nanocomposite Biomaterials in Orthopedic Trauma Surgery

Abstract

With the continuous development of technology, using biological three-dimensional (3D) printing technology to prepare hydrogel stent for cartilage construction has great potential in soft tissue repair. In this study, the cartilage stent was prepared by cell-controlled assembly technology, the gelatin sodium alginate (GSA) was selected as the basic material and the nano-hydroxyapatite (n-HAP) was undertaken as the reinforcing material of the basic hydrogel, and the cell-controlled technology was used to assemble the n-HAP hydrogel stent with different composite ratios. While the performance of the stent material was characterized, the hydrogel material prepared for traumatic thoracolumbar fracture (TTF) was adopted for filling treatment during the percutaneous kyphoplasty (PKP). The results showed that compared with the GSA stent, addition of n-HAP can optimize accuracy of 3D printing, increase stability and mechanical strength of stent, and tested average elastic modulus of the composite hydrogel material is 24.58 ± 1.05 MPa. It suggested that addition of n-HAP can improve biodegradability of stent while adjusting the surface roughness of the stent. The biocompatibility test of n-HAP hydrogel stent indicated that the stent material was non-toxic and could support the adhesion and growth of mouse chondrocytes. After culture for 1 week after the 3D printing, the proportion of living cells reached more than 90%. Under the action of the composite hydrogel stent material, the visual analogue scale (VAS) score of patient decreased dramatically (from 8.9 to 1.8), the Oswestry disability index (ODI) decreased from 83.65 before surgery to 36.89 after surgery (P < 0.05), and the anterior vertebral height (AVH) of patient increased from 2.46 cm to 2.96 cm, which was 2.76 cm in the last follow-up test (P < 0.05). In summary, the composite hydrogel stent prepared in this study could meet the needs of cartilage tissue factories and showed good clinical effects in the treatment of TTF.