Controlled release of biological factors for endogenous progenitor cell migration and intervertebral disc extracellular matrix remodelling
Controlled release of biological factors for endogenous progenitor cell migration and intervertebral disc extracellular matrix remodelling
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DOI：
10.1016/j.biomaterials.2020.120107
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发表时间：
2020-09-01
期刊：
影响因子：
14
通讯作者：
Le Visage, Catherine
中科院分区：
文献类型：
--
作者：
Frapin, Leslie;Clouet, Johann;Le Visage, Catherine
最近对退变椎间盘（IVD）中常驻干细胞/祖细胞的描述支持了这样一种观点，即可以利用其再生能力来刺激髓核（NP）的内源性修复。在这项研究中，我们开发了一种基于普鲁兰多糖微珠（PMBs）的递送系统，用于顺序释放趋化因子CCL-5，以将这些椎间盘干/祖细胞招募到NP组织，然后释放生长因子TGF-β 1和GDF-5，以诱导合成富含II型胶原和聚集蛋白聚糖的细胞外基质（ECM）。使用Transwell（R）趋化性测定证明释放的CCL 5对人脂肪来源的干细胞（hASC）的生物活性，所述hASC被选择来模拟椎间盘干细胞/祖细胞。在离体自发退化的绵羊IVD中研究了负载PMB的再生效果。将荧光hASC接种在顶部软骨终板（CEP）上;将退化的NP注射载有CCL 5、TGF-β 1和GDF-5的PMB;然后将IVD培养3、7和28天以允许细胞迁移和椎间盘再生。PMB表现出持续释放生物因子21天。证明了接种的hASC从CEP向NP的离体迁移，其中当注射加载的PMB时，细胞迁移显著更大的距离（5.8 +/-1.3mm对3.5 +/-1.8mm，没有注射PMB）。在绵羊IVD中，与对照组相比，在第28天NP中的总体NP细胞结构、II型胶原和聚集蛋白聚糖染色强度以及Tie 2+祖细胞密度增加。综合考虑，负载CCL 5/TGF-β 1/GDF-5的PMB构成了一种创新且有前途的生长因子控制释放策略，以促进细胞募集和细胞外基质重塑。
The recent description of resident stem/progenitor cells in degenerated intervertebral discs (IVDs) supports the notion that their regenerative capacities could be harnessed to stimulate endogenous repair of the nucleus pulposus (NP). In this study, we developed a delivery system based on pullulan microbeads (PMBs) for sequential release of the chemokine CCL-5 to recruit these disc stem/progenitor cells to the NP tissue, followed by the release of the growth factors TGF-beta 1 and GDF-5 to induce the synthesis of a collagen type II- and aggrecan-rich extracellular matrix (ECM). Bioactivity of released CCL5 on human adipose-derived stem cells (hASCs), selected to mimic disc stem/progenitors, was demonstrated using a Transwell (R) chemotaxis assay. The regenerative effects of loaded PMBs were investigated in ex vivo spontaneously degenerated ovine IVDs. Fluorescent hASCs were seeded on the top cartilaginous endplates (CEPs); the degenerated NPs were injected with PMBs loaded with CCL5, TGF-beta 1, and GDF-5; and the IVDs were then cultured for 3, 7, and 28 days to allow for cell migration and disc regeneration. The PMBs exhibited sustained release of biological factors for 21 days. Ex vivo migration of seeded hASCs from the CEP toward the NP was demonstrated, with the cells migrating a significantly greater distance when loaded PMBs were injected (5.8 +/- 1.3 mm vs. 3.5 +/- 1.8 mm with no injection of PMBs). In ovine IVDs, the overall NP cellularity, the collagen type II and the aggrecan staining intensities, and the Tie2+ progenitor cell density in the NP were increased at day 28 compared to the control groups. Considered together, PMBs loaded with CCL5/TGF-beta 1/GDF-5 constitute an innovative and promising strategy for controlled release of growth factors to promote cell recruitment and extracellular matrix remodelling.