Purpose: Autologous bone grafts are the gold standard for treating bone defects. However, limited bone supply and morbidity at the donor site restrict its extensive use. Therefore, developing bone graft materials as an alternative to autologous grafts has gained considerable attention. Injectable hydrogels endowed with osteogenic potential have the ability to fill irregular bone defects using minimally invasive procedures and have thus been attracting researchers’ attention. However, from a clinical perspective, most fabrication methods employed for the current injectable osteogenic hydrogels are difficult and inconvenient. In the current study, we fabricated an injectable osteogenic hydrogel using a simple and convenient strategy.
Materials and Methods: Gelatin-methacryloyl (GelMA) pre-polymer was synthetized. Nano silicate (SN) and stromal cell-derived factor-1 alpha (SDF-1α) were introduced into the pre-polymer to achieve injectability, controlled release property, excellent osteogenic ability, and efficient stem cell homing.
Results: The GelMA-SN-SDF-1α demonstrated excellent injectability via a 17-G needle at room temperature. The loaded SDF-1α exhibited a long-term controlled release pattern and efficiently stimulated MSC migration and homing. The GelMA-SN-SDF-1α hydrogel amplified cell spreading, migration, osteogenic-related biomarker expression, and matrix mineralization. The GelMA-SN-SDF-1α hydrogel filled critical-sized calvaria defects in rats and demonstrated excellent bone regeneration ability, as assessed using micro-CT scanning and histomorphometric staining.
Conclusion: The GelMA-SN-SDF-1α hydrogel provides a simple and convenient strategy for the fabrication of injectable osteogenic graft materials.

Keywords: bone defects, gelatin methacryloyl hydrogels, injectable, nano-silicate, SDF-1α, osteogenic


中文翻译：

---

用于骨组织工程的纳米硅酸盐增强和 SDF-1α 负载明胶-甲基丙烯酰水凝胶

目的：自体骨移植是治疗骨缺损的金标准。然而，供体部位有限的骨供应和发病率限制了其广泛使用。因此，开发骨移植材料作为自体移植物的替代品已引起相当大的关注。具有成骨潜力的可注射水凝胶具有使用微创手术填充不规则骨缺损的能力，因此引起了研究人员的关注。然而，从临床角度来看，目前可注射成骨水凝胶所采用的大多数制造方法都是困难且不方便的。在目前的研究中，我们使用简单方便的策略制造了一种可注射的成骨水凝胶。
材料和方法：合成明胶-甲基丙烯酰基（GelMA）预聚物。将纳米硅酸盐（SN）和基质细胞衍生的因子-1α（SDF-1α）引入预聚物中，以实现可注射性、控释性、优异的成骨能力和高效的干细胞归巢。
结果：GelMA-SN-SDF-1α 在室温下通过 17-G 针头表现出出色的可注射性。负载的 SDF-1α 表现出长期控制释放模式并有效地刺激 MSC 迁移和归巢。GelMA-SN-SDF-1α 水凝胶可放大细胞扩散、迁移、成骨相关生物标志物表达和基质矿化。GelMA-SN-SDF-1α 水凝胶填充了大鼠临界大小的颅盖骨缺损，并显示出出色的骨再生能力，使用显微 CT 扫描和组织形态学染色进行评估。
结论： GelMA-SN-SDF-1α 水凝胶为制造可注射成骨移植材料提供了一种简单方便的策略。

关键词：骨缺损，明胶甲基丙烯酰水凝胶，可注射，纳米硅酸盐，SDF-1α，成骨