Mechanisms of pNaSS-grafted poly(epsilon)-caprolactone scaffolds for enhanced rAAV-mediated gene transfer in human bone marrow-derived mesenchymal stem cells

局灶性关节软骨病变仍然是骨科手术中主要的、尚未解决的问题，因为迄今为止没有一种治疗方法可以完全恢复原生软骨的结构和功能（机械）完整性。重组腺相关病毒（rAAV）载体是一种有效的、临床适应性强的重组腺相关病毒（rAAV）载体，通过递送高度成软骨基因，如转化生长因子β （TGF-ß）和软骨特异性性别决定区y型高迁移率组盒9 （SOX9）转录因子，在软骨损伤部位靶向存在于软骨再生间充质干细胞（MSCs）的天然、浓缩微环境中。然而，尽管rAAV载体获得了欧洲医药机构的市场授权，用于治疗患者的脂蛋白脂肪酶缺乏症，但由于人群中天然存在针对病毒衣壳蛋白的中和抗体，以及载体可能传播到非靶组织，rAAV载体在临床中的安全、转化应用仍然受到阻碍。为了解决这些问题，本研究的目标是验证一种假设，即治疗性rAAV （TGF-ß， SOX9）载体可以通过涂层递送到生物相容性的固体聚苯乙烯磺酸钠(pNaSS)-聚(epsilon)-己内酯（PCL）支架上，作为受控基因递送系统，安全、有效、局部和持久地增强体外天然、原代浓缩hMSCs中软骨修复相关的软骨形成过程和机制。在翻译前骨软骨培养模型中，以及在体内翻译骨软骨缺陷中。该项目可能在不久的将来提供新的、有效的治疗方法来增强患者的软骨修复。

Focal articular cartilage lesions remain major, unresolved problems in orthopaedic surgery as none of the therapeutic options available thus far can fully restore the structural and functional (mechanical) integrity of the native cartilage. Administration of the potent, clinically adapted recombinant adeno-associated virus (rAAV) vectors in sites of cartilage injury is a strong approach to target the resident, chondroregenerative mesenchymal stem cells (MSCs) within their natural, concentrated microenvironment by delivery of highly chondrogenic genes such as the transforming growth factor beta (TGF-ß) and cartilage-specific sex-determining region Y-type high mobility group box 9 (SOX9) transcription factor. However, while rAAV vectors received market authorization from the European Medicine Agencies to treat lipoprotein lipase deficiency in patients, the safe, translational application of rAAV vectors in the clinics still remains hindered by the natural presence of neutralizing antibodies against the viral capsid proteins in the human population and by a possible dissemination of the vectors to nontarget tissues. To address these issues, the goal of the present proposal is to test the hypothesis that therapeutic rAAV (TGF-ß, SOX9) vectors may be delivered via coating onto biocompatible, solid poly(sodium styrene sulfonate) (pNaSS)-grafted poly(epsilon)-caprolactone (PCL) scaffolds as controlled gene delivery systems to safely, effectively, locally, and durably enhance the chondrogenic processes and mechanisms relevant of cartilage repair in natural, primary concentrated hMSCs in vitro, in a pre-translational osteochondral culture model, and in translational osteochondral defects in vivo. This project may offer new, effective therapies to enhance cartilage repair in patients in a close future.