Abstract

At present, the treatment of bone defect is one of the most concerned problems in biomedical fields. Despite the wide variety of scaffolds, there is a challenge to select materials that can mimic the structural integrity and biocompatibility of natural bone. In our study, gelatin methacryloyl (GelMA) and sodium alginate (Alg) were used to prepare three-dimensional (3D) GelMA/Alg hybrid hydrogel, which can simulate the structure and biological function of natural extracellular matrix due to their high water content and porous structure. The interconnected and homogeneous pores of the scaffold facilitate the transport of nutrients during the bone regeneration. Then hydroxyapatite (HA) coated GelMA/Alg (GelMA/Alg-HA) hydrogel was obtained by sequential mineralization. The mineralized hydrogel was obtained by immersing hydrogel alternately in a solution of calcium and phosphorus at 37 °C. The hydrogel was modified with a coating of HA under a mild condition. The calcium crosslinked Alg could provide nucleation sites for HA crystals. And the sequential mineralization will improve the physical properties and osteoinductivity of the hydrogels by introducing HA, which is similar to the mineral component of natural bone. Analytical results confirmed that the HA particles were uniformly distributed in the surface of the hydrogels and the mineral contents were about 40% after three cycles. The compressive strength was improved from 22.43 ± 6.39 to 131.03 ± 9.26 kPa. In addition, MC3T3-E1 cell co-culture experiments shown that the mineralized GelMA/Alg-HA hybrid hydrogel possess good biocompatibility, which is conducive to the growth of new bone tissue and bone repair.

摘要

目前，骨缺损的治疗是生物医学领域最为关注的问题之一。尽管支架种类繁多，但选择可以模仿天然骨的结构完整性和生物相容性的材料仍然存在挑战。在我们的研究中，明胶甲基丙烯酰 (GelMA) 和海藻酸钠 (Alg) 被用于制备三维 (3D) GelMA/Alg 混合水凝胶，由于其高含水量和可模拟天然细胞外基质的结构和生物学功能，多孔结构。支架的相互连接且均质的孔有助于骨再生过程中营养物质的运输。然后通过顺序矿化获得羟基磷灰石（HA）包覆的GelMA/Alg（GelMA/Alg-HA）水凝胶。通过将水凝胶交替浸入37℃的钙和磷溶液中获得矿化水凝胶。在温和条件下用 HA 涂层对水凝胶进行改性。钙交联的 Alg 可以为 HA 晶体提供成核位点。并且顺序矿化将通过引入类似于天然骨的矿物质成分的HA来改善水凝胶的物理性质和骨诱导性。分析结果证实，HA颗粒均匀分布在水凝胶表面，三个循环后矿物质含量约为40%。抗压强度从 22.43 ± 6.39 提高到 131.03 ± 9.26 kPa。此外，MC3T3-E1细胞共培养实验表明矿化GelMA/Alg-HA杂化水凝胶具有良好的生物相容性，