Articular Joint-Simulating Mechanical Load Activates Endogenous TGF-β in a Highly Cellularized Bioadhesive Hydrogel for Cartilage Repair
Articular Joint-Simulating Mechanical Load Activates Endogenous TGF-β in a Highly Cellularized Bioadhesive Hydrogel for Cartilage Repair
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DOI：
10.1177/0363546519887909
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发表时间：
2020-01-01
影响因子：
4.8
通讯作者：
Armiento, Angela Rita
中科院分区：
文献类型：
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作者：
Behrendt, Peter;Ladner, Yann;Armiento, Angela Rita
背景：骨软骨缺陷(OCDs)的治疗是骨科医生面临的主要问题。力学和细胞类型的改变，以及来自暴露的软骨下骨的相关可溶性因子，可能是随后获得作为修复组织的力学和结构上较低的关节软骨的原因。因此，临床上对生物响应性生物材料的需求尚未得到满足，这些材料允许细胞输送，减少细胞在骨髓中的渗透，并支持关节机械载荷下的软骨形成。目的：研制一种具有生物粘附性、低侵袭性和良好机械阻力的细胞可注射生物材料，其中模拟关节载荷可通过产生和激活转化生长因子-β1(TGF-β1)来诱导组织成熟。研究设计：对照实验室研究。方法：将人骨髓间充质干细胞包裹在酪胺修饰的透明质酸(HA-Tyr)水凝胶中，通过加入辣根过氧化物酶(HRP)和不同浓度的过氧化氢(0.3-2 mM)引发交联。通过活/死染色、流变学和推出试验分别分析细胞相容性、生物力学和粘附性。对于多轴载荷，载细胞水凝胶在0.5-N预载荷和剪切载荷(+/-25度)上叠加10%的压缩，每天1小时，每周5次，持续4周。采用酶联免疫吸附试验(EL ISA)检测细胞转化生长因子-β1的产生和活性。结果：在不同的细胞密度和HRP/H2O2浓度范围内，不同比例的HRP和H_2O_2交联的HA-Tyr水凝胶具有良好的粘弹性。在没有血清补充的情况下，细胞对HA-Tyr水凝胶的侵袭很小甚至没有。与临床使用的纤维蛋白凝胶相比，HA-Tyr与关节软骨的结合强度更好。结论：HA-Tyr水凝胶具有机械调节作用，可诱导包埋细胞产生内源性转化生长因子-β1。HA-Tyr水凝胶作为细胞载体支持生物力学诱导的转化生长因子-β1的产生和激活，以及作为低细胞侵袭性的生物黏附材料，表明它们有望成为强迫症修复策略的一种新型生物材料。
Background: The treatment of osteochondral defects (OCDs) constitutes a major problem for orthopaedic surgeons. The altered mechanics and the cell types, with associated soluble factors derived from the exposed subchondral bone, are likely responsible for the mechanically and structurally inferior articular cartilage subsequently obtained as a repair tissue. There is therefore an unmet clinical need for bioresponsive biomaterials that allow cell delivery, reduce cell infiltration from the bone marrow, and support chondrogenesis in the presence of joint mechanical loading. Purpose: To develop a cell-laden injectable biomaterial, with bioadhesive properties, low cell invasion, and good mechanoresilience, in which simulated joint loading could induce tissue maturation through the production and activation of transforming growth factor beta 1 (TGF-beta 1). Study Design: Controlled laboratory study. Methods: Human bone marrow-derived mesenchymal stromal/stem cells were encapsulated in tyramine-modified hyaluronic acid (HA-Tyr) hydrogels, with crosslinking initiated by the addition of horseradish peroxidase (HRP) and various concentrations of hydrogen peroxide (H2O2; 0.3-2 mM). Cytocompatibility and biomechanical and adhesive properties were analyzed by live/dead staining, rheology, and push-out test, respectively. For multiaxial loading, cell-laden hydrogels were subjected to 10% compression superimposed onto a 0.5-N preload and shear loading (+/- 25 degrees) at 1 Hz for 1 hour per day and 5 times a week for 4 weeks. TGF-beta 1 production and activation were measured by enzyme-linked immunosorbent assay (ELISA). Results: The viscoelastic properties of the cell-laden HA-Tyr hydrogels, as crosslinked with different ratios of HRP and H2O2, were demonstrated for a range of cell densities and HRP/H2O2 concentrations. In the absence of serum supplementation, cell invasion into HA-Tyr hydrogels was minimal to absent. The bonding strength of HA-Tyr to articular cartilage compared favorably with clinically used fibrin gel. Conclusion: HA-Tyr hydrogels can be mechanically conditioned to induce activation of endogenous TGF-b1 produced by the embedded cells. HA-Tyr hydrogels function as cell carriers supporting biomechanically induced production and activation of TGF-beta 1 and as bioadhesive materials with low cell invasion, suggesting that they hold promise as a novel biomaterial for OCD repair strategies.