Department of Oncology and Metabolism, Medical School, The University of Sheffield, Sheffield, UK.
Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK.
Biomater Sci. 2023 Jun 27;11(13):4630-4643. doi: 10.1039/d3bm00150d.
Back pain is the leading cause of disability with half of cases attributed to intervertebral disc (IVD) degeneration, yet currently no therapies target this cause. We previously reported an caprine loaded disc culture system (LDCS) that accurately represents the cellular phenotype and biomechanical environment of human IVD degeneration. Here, the efficacy of an injectable hydrogel system (LAPONITE® crosslinked pNIPAM--DMAc, (NPgel)) to halt or reverse the catabolic processes of IVD degeneration was investigated within the LDCS. Following enzymatic induction of degeneration using 1 mg mL collagenase and 2 U mL chondroitinase ABC within the LDCS for 7 days, IVDs were injected with NPgel alone or with encapsulated human bone marrow progenitor cells (BMPCs). Un-injected caprine discs served as degenerate controls. IVDs were cultured for a further 21 days within the LDCS. Tissues were then processed for histology and immunohistochemistry. No extrusion of NPgel was observed during culture. A significant decrease in histological grade of degeneration was seen in both IVDs injected with NPgel alone and NPgel seeded with BMPCs, compared to un-injected controls. Fissures within degenerate tissue were filled by NPgel and there was evidence of native cell migration into injected NPgel. The expression of healthy NP matrix markers (collagen type II and aggrecan) was increased, whereas the expression of catabolic proteins (MMP3, ADAMTS4, IL-1β and IL-8) was decreased in NPgel (±BMPCs) injected discs, compared to degenerate controls. This demonstrates that NPgel promotes new matrix production at the same time as halting the degenerative cascade within a physiologically relevant testing platform. This highlights the potential of NPgel as a future therapy for IVD degeneration.
背痛是导致残疾的主要原因，其中一半病例归因于椎间盘（IVD）退变，但目前尚无针对该病因的治疗方法。我们之前报道了一种山羊负载的椎间盘培养系统（LDCS），该系统准确地代表了人类 IVD 退变的细胞表型和生物力学环境。在这里，研究了一种可注射水凝胶系统（LAPONITE®交联 pNIPAM-DMAC，（NPgel））在 LDCS 内阻止或逆转 IVD 退变的分解代谢过程的疗效。在 LDCS 内用 1mg/mL 胶原酶和 2U/mL 软骨素酶 ABC 酶诱导退变 7 天后，单独注射 NPgel 或包封人骨髓祖细胞（BMPC）的 NPgel 注入 IVD。未注射的山羊椎间盘作为退变对照。IVD 在 LDCS 内进一步培养 21 天。然后对组织进行组织学和免疫组织化学处理。在培养过程中未观察到 NPgel 的挤出。与未注射对照相比，单独注射 NPgel 和 NPgel 接种 BMPC 的 IVD 的退变组织学分级均显著降低。NPgel 填充退变组织中的裂隙，并且有证据表明天然细胞迁移到注入的 NPgel 中。NP 基质健康标志物（II 型胶原和聚集蛋白聚糖）的表达增加，而 NPgel（±BMPC）注射的椎间盘内分解代谢蛋白（MMP3、ADAMTS4、IL-1β 和 IL-8）的表达降低，与退变对照相比。这表明 NPgel 不仅可以阻止生理相关测试平台内的退行性级联反应，还可以促进新基质的产生。这突显了 NPgel 作为 IVD 退变未来治疗方法的潜力。
