Purpose: Given that autologous bone graft for bone defects is limited by insufficient supply and morbidity at the donor site, developing biomimetic graft materials as an alternative has gained consistent attention. However, obstacles in designing bone-mimetic materials that could integrate the biomimetic nature of the bone extracellular matrix, osteogenic cells, and osteoinductive ingredients with a fast and convenient strategy still exist.
Methods: This study designed and fabricated a mesenchymal stem cell (MSC)-laden, nanohydroxyapatite (HAP), and nanosilicate (SN)-loaded bone mimetic and injectable gelatin-methacryloyl hydrogel (GelMA-HAP-SN) system for bone tissue engineering, and systemically investigated the osteogenic capacity of GelMA-HAP-SN in vitro and in vivo.
Results: Introducing HAP enhanced the compositional similarity to the natural bone extracellular matrix, and SN loading endowed the hydrogel with injectable and osteogenic ability. As a result, the GelMA-HAP-SN hydrogel demonstrated an increase in cellular viability, proliferation, and spreading behavior. The GelMA-HAP-SN hydrogel also amplified the embedded MSCs’ osteogenic biomarkers’ expression and matrix mineralization. Furthermore, the MSC-encapsulated GelMA-HAP-SN hydrogel was injected into rats’ critical-sized calvaria defect, and micro-CT and histomorphometry staining results further confirmed its excellent bone regeneration ability.
Conclusion: These MSC-loaded GelMA-HAP-SN hydrogels are potential graft materials for bone defect treatment.

Keywords: GelMA, injectable, biomimetic, nanohydroxyapatite, nanosilicate, bone regeneration


中文翻译：

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用于骨组织工程的纳米羟基磷灰石、纳米硅酸盐增强注射剂和仿生明胶-甲基丙烯酰水凝胶


目的：鉴于用于骨缺损的自体骨移植受到供体部位供应不足和发病率的限制，开发仿生移植材料作为替代方案受到了一致的关注。然而，设计能够以快速便捷的策略整合骨细胞外基质、成骨细胞和骨诱导成分的仿生性质的仿骨材料仍然存在障碍。

方法：本研究设计并制造了一种负载间充质干细胞（MSC）、纳米羟基磷灰石（HAP）和纳米硅酸盐（SN）的骨模拟和可注射明胶-甲基丙烯酰水凝胶（GelMA-HAP-SN）系统，用于骨组织工程，并系统研究了 GelMA-HAP-SN 的体外和体内成骨能力。

结果： HAP的引入增强了与天然骨细胞外基质的组成相似性，SN的负载赋予了水凝胶可注射和成骨的能力。结果，GelMA-HAP-SN 水凝胶表现出细胞活力、增殖和扩散行为的增加。 GelMA-HAP-SN 水凝胶还放大了嵌入的 MSC 的成骨生物标志物的表达和基质矿化。此外，将MSC封装的GelMA-HAP-SN水凝胶注射到大鼠临界大小的颅盖缺损中，显微CT和组织形态计量学染色结果进一步证实了其优异的骨再生能力。

结论：这些负载 MSC 的 GelMA-HAP-SN 水凝胶是用于骨缺损治疗的潜在移植材料。


关键词： GelMA，注射剂，仿生，纳米羟基磷灰石，纳米硅酸盐，骨再生