Injectable hydrogels effectively remodel degenerative nucleus pulposus (NP) with a resemblance to the in vivo microenvironment. However, the pressure within the intervertebral disc requires load-bearing implants. The hydrogel must undergo a rapid phase transition upon injection to avoid leakage. In this study, an injectable sodium alginate hydrogel was reinforced with silk fibroin nanofibers with core-shell structures. The nanofiber-embedded hydrogel provided support to adjacent tissues and facilitated cell proliferation. Platelet-rich plasma (PRP) was incorporated into the core-shell nanofibers for sustained release and enhanced NP regeneration. The composite hydrogel exhibited excellent compressive strength and enabled leak-proof delivery of PRP. In rat intervertebral disc degeneration models, radiography and MRI signal intensities were significantly reduced after 8 weeks of injections with the nanofiber-reinforced hydrogel. The biomimetic fiber gel-like structure was constructed in situ, providing mechanical support for NP repair, promoting the reconstruction of the tissue microenvironment, and finally realizing the regeneration of NP.

可注射水凝胶有效重塑退化髓核 (NP)，与体内相似微环境。然而，椎间盘内的压力需要承重植入物。水凝胶在注射时必须经历快速相变以避免泄漏。在这项研究中，可注射海藻酸钠水凝胶用具有核壳结构的丝素蛋白纳米纤维增强。嵌入纳米纤维的水凝胶为邻近组织提供支持并促进细胞增殖。将富含血小板的血浆 (PRP) 掺入核壳纳米纤维中，以实现持续释放和增强 NP 再生。复合水凝胶表现出优异的抗压强度，可实现 PRP 的防漏输送。在大鼠椎间盘退变模型中，注射纳米纤维增强水凝胶 8 周后，射线照相和 MRI 信号强度显着降低。原位，为NP修复提供机械支持，促进组织微环境的重建，最终实现NP的再生。