Gelatin cryogels are good candidate scaffolds for tissue engineering because of their interconnected macroporous structure. For bone regeneration, inorganic components are chosen to reinforce gelatin cryogels: (i) to mimic the compositions of natural bone tissue and (ii) to meet the mechanical requirements of bone repairing. Cryogels were prepared from methacrylated gelatin (GelMA) in this study, and hydroxyapatite nanorods (HANRs) with surface-grafted acrylate groups (D-HANRs) were synthesized to reinforce the cryogels, in which, the crosslinking between GelMA and D-HANRs was expected. In parallel, HANRs and hydroxyapatite nanowires (HANWs) were also composited with the GelMA cryogels to investigate the effects of filler morphology and interfacial bonding on the overall properties of the resulting composite cryogels comparatively. All these composite cryogels demonstrated potential as bone repairing materials by displaying excellent performances such as high porosity, appropriate water retention, shape recovery, and fast resilience features, as well as good biocompatibility and cell affinity. In comparison with the HANR composited GelMA cryogel, the HANWs were able to ameliorate the compression and the rheology performances of the resulting composite cryogels more efficiently due to the fact that the one-dimensional HANWs played a bridging role in the gelatin matrix. Among all the preparations, however, it was the D-HANRs that achieved the strongest reinforcement efficiency in mechanical properties because the double bonds on their surface could be photo-crosslinked with GelMA to form interfacial bonding. With these findings, we concluded that it was preferable for inorganic fillers designed for cryogel-type bone repairing materials to be in a one-dimensional morphology with surface functional groups to strengthen their interfacial bonding with the polymeric matrix.

中文翻译：

---

不同形态和界面结合的羟基磷灰石增强明胶冰晶的比较研究。

明胶冷冻凝胶由于其相互连接的大孔结构而成为组织工程的良好候选支架。对于骨再生，选择无机成分以增强明胶凝胶：（i）模拟天然骨组织的成分，（ii）满足骨修复的机械要求。在这项研究中，由甲基丙烯酸明胶（GelMA）制备了冰晶，并合成了具有表面接枝丙烯酸酯基团（D-HANRs）的羟基磷灰石纳米棒（HANRs）来增强冰晶石，其中有望实现GelMA与D-HANRs之间的交联。同时，还将HANR和羟基磷灰石纳米线（HANW）与GelMA低温凝胶复合，以比较研究填料形态和界面键合对所得复合低温凝胶总体性能的影响。所有这些复合冰晶通过表现出优异的性能（例如高孔隙率，适当的保水率，形状恢复和快速的回​​弹特性）以及良好的生物相容性和细胞亲和力，证明具有作为骨修复材料的潜力。与HANR复合GelMA冷冻凝胶相比，由于一维HANW在明胶基质中起着桥接作用，因此HANW能够更有效地改善所得复合冷冻凝胶的压缩和流变性能。然而，在所有制剂中，D-HANRs在机械性能方面实现了最强的增强效率，因为其表面上的双键可以与GelMA光交联形成界面键合。有了这些发现，