Table1_Osteogenesis of Iron Oxide Nanoparticles-Labeled Human Precartilaginous Stem Cells in Interpenetrating Network Printable Hydrogel.DOCX

Smart biomaterials combined with stem cell-based therapeutic strategies have brought innovation in the field of bone tissue regeneration. However, little is known about precartilaginous stem cells (PCSCs), which can be used as seed cells and incorporated with bioactive scaffolds for reconstructive tissue therapy of bone defects. Herein, iron oxide nanoparticles (IONPs) were employed to modulate the fate of PCSCs, resulting in the enhanced osteogenic differentiation potential both in vitro and in vivo. PCSCs were isolated from the ring of La-Croix extracted from polydactylism patient and identified through immunohistochemically staining using anti-FGFR-3 antibodies. Potential toxicity of IONPs toward PCSCs was assessed through cell viability, proliferation, and attachment assay, and the results demonstrated that IONPs exhibited excellent biocompatibility. After that, the effects of IONPs on osteogenic differentiation of PCSCs were evaluated and enhanced ALP activity, formation of mineralized nodule, and osteogenic-related genes expressions could be observed upon IONPs treatment. Moreover, in vivo bone regeneration assessment was performed using rabbit femur defects as a model. A novel methacrylated alginate and 4-arm poly (ethylene glycol)-acrylate (4A-PEGAcr)-based interpenetrating polymeric printable network (IPN) hydrogel was prepared for incorporation of IONPs-labeled PCSCs, where 4A-PEGAcr was the common component for three-dimensional (3D) printing. The implantation of IONPs-labeled PCSCs significantly accelerated the bone formation process, indicating that IONPs-labeled PCSCs could endow current scaffolds with excellent osteogenic ability. Together with the fact that the IONPs-labeled PCSCs-incorporated IPN hydrogel (PCSCs-hydrogels) was biosafety and printable, we believed that PCSCs-hydrogels with enhanced osteogenic bioactivity could enrich the stem cell-based therapeutic strategies for bone tissue regeneration.

智能生物材料与基于干细胞的治疗策略相结合，为骨组织再生领域带来了革新。然而，目前对软骨前干细胞（precartilaginous stem cells, PCSCs）的认知仍较为匮乏：这类细胞可作为种子细胞，与生物活性支架结合用于骨缺损的修复性组织治疗。本研究采用氧化铁纳米颗粒（iron oxide nanoparticles, IONPs）调控软骨前干细胞的细胞命运，最终在体外与体内均实现了其成骨分化潜能的显著增强。研究人员从多指畸形患者提取的拉克鲁瓦环（La-Croix环）中分离得到软骨前干细胞，并通过抗FGFR-3抗体进行免疫组织化学染色，完成细胞鉴定。通过细胞活力、增殖及黏附实验评估了氧化铁纳米颗粒对软骨前干细胞的潜在毒性，结果显示该纳米颗粒具备优异的生物相容性。随后，研究人员评估了氧化铁纳米颗粒对软骨前干细胞成骨分化的影响，发现经氧化铁纳米颗粒处理后，可观察到碱性磷酸酶（ALP）活性提升、矿化结节形成增多以及成骨相关基因表达上调。此外，本研究以兔股骨缺损为模型开展了体内骨再生评价：研究制备了一种基于甲基丙烯酸酯化海藻酸盐与四臂聚乙二醇丙烯酸酯（4-arm poly (ethylene glycol)-acrylate, 4A-PEGAcr）的可打印互穿聚合物网络（interpenetrating polymeric printable network, IPN）水凝胶，用于负载经氧化铁纳米颗粒标记的软骨前干细胞，其中四臂聚乙二醇丙烯酸酯是三维（3D）打印的常用组分。植入经氧化铁纳米颗粒标记的软骨前干细胞可显著加速骨形成进程，表明此类标记后的细胞可赋予现有支架优异的成骨能力。结合负载经氧化铁纳米颗粒标记软骨前干细胞的IPN水凝胶（PCSCs-hydrogels）具备生物安全性与可打印性这一事实，我们认为具备增强型成骨生物活性的PCSCs水凝胶，可丰富用于骨组织再生的基于干细胞的治疗策略。