Introducing a Chondroinductive Peptide

项目总结 长期目标是获得一种软骨诱导生物材料，用于再生受损的软骨。在……里面 治疗局灶性软骨损伤患者，防止进展为骨关节炎的最大挑战 正在实现真正的功能性透明软骨。多肽已经成为一种令人兴奋的选择，可以增强 平移类可复制的生物材料，可以在不需要 增长因素。对多肽的发现采取了一种完全不同的方法，问题是 两种不同的软骨诱导分子--聚集素和转化生长因子-β-3--可能有一些共同之处。通过一个 将aggrecan的核心蛋白序列与转化生长因子-β3蛋白进行比较，鉴定出一种新的多肽 序列：SPPEPS。该多肽在大鼠骨髓软骨形成中的作用优于阴性对照。 衍生细胞(RBMSCs)在我们的初步研究。此外，与基因相关的基因上调 观察到了软骨生成，初步的蛋白质组学分析表明，有一些途径与 转化生长因子-β表达上调。有趣的是，我们发现RGD和SPPEPS具有很强的协同效应 骨髓间充质干细胞的II型胶原基因的表达比单独使用这两种多肽高出一个数量级。在我们的 首次在体内尝试，戊烯酸修饰的透明质酸(PHA)水凝胶和SPPEPS导致了II型胶原的形成 兔股骨内侧髁骨缺损处植入12周后免疫组织化学染色可见 陷窝内有软骨细胞样细胞。因此，这一提议的目的是检验去细胞的主要假设 含有软骨诱导肽SPPEPS的PHA将导致功能类似的透明软骨 对健康的天然软骨，具体目的如下：1)增强SPPEPS的协同软骨诱导作用 用BMSC结合肽，以及2)用PHA-2)再生兔膝关节功能性透明软骨。 SPPEPS水凝胶。 目的1探讨SPPEPS对人骨髓间充质干细胞球体的软骨诱导作用，包括转化生长因子-β途径。 分析，随后对种植或包裹在PHA水凝胶中的rBMSCs进行了研究 一种骨髓间充质干细胞结合肽。AIM 2将利用AIM 1的发现将PHA水凝胶植入兔的内侧 股骨髁软骨缺损的功能分析比较 再生软骨的结构和力学性能。 这个R21项目的成功完成提供了软骨再生的范式转变，具有潜在的 引入一种可重复、低成本、仅使用材料的能够再生玻璃体的装置的临床影响 软骨对于膝关节软骨损伤患者来说，是生物材料领域的一个旗舰 软骨诱导肽，别人可以很容易地融入到自己的新材料中，并产生持久的影响 通过在全球范围内探索软骨形成的多肽发现方法，开辟了一条新的途径。

PROJECT SUMMARY The long-term goal is to achieve a chondroinductive biomaterial implant for regenerating injured cartilage. In treating a patient with a focal cartilage injury, the greatest challenge in preventing the progression to osteoarthritis is achieving true functional hyaline cartilage. Peptides have emerged as an exciting option to empower a translational class of reproducible biomaterials that may be capable of chondroinduction without the need for growth factors. An entirely different approach to peptide discovery was taken by asking the question of whether two different chondroinductive molecules—aggrecan and TGF-β3—may have anything in common. Through a comparison of aggrecan’s core protein sequence and the TGF-β3 proprotein, we identified a single novel peptide sequence: SPPEPS. This peptide has outperformed negative controls in chondrogenesis of rat bone marrow- derived cells (rBMSCs) in our preliminary studies. Moreover, upregulation of genes associated with chondrogenesis was observed, with preliminary proteomic analyses suggesting some pathways in common with TGF-β upregulation. Interestingly, we discovered that RGD and SPPEPS had a powerful synergistic effect with an order of magnitude greater collagen II gene expression by MSCs compared to either peptide alone. In our first in vivo attempt, pentenoate-modified hyaluronic acid (PHA) hydrogels with SPPEPS led to collagen II immunostaining 12 weeks after implantation in rabbit medial femoral condyle defects, with visible columns of chondrocyte-like cells in lacunae. The objective of this proposal is thus to test the chief hypothesis that acellular PHA with the chondroinductive peptide SPPEPS will lead to hyaline-like cartilage that is functionally comparable to healthy native cartilage, with the following specific aims: 1) Enhance synergistic chondroinductivity of SPPEPS with a BMSC-binding peptide, and 2) Regenerate functional hyaline cartilage in rabbit knees with the PHA- SPPEPS hydrogel. Aim 1 will explore SPPEPS chondroinduction on rBMSC spheroids, including a mechanistic TGF-β pathway analysis, followed by an investigation of rBMSCs seeded or encapsulated in PHA hydrogels with SPPEPS and a BMSC-binding peptide. Aim 2 will leverage the findings of Aim 1 to implant PHA hydrogels in rabbit medial femoral condylar cartilage defects, including a comparison between males and females with functional analysis of the structure and mechanical performance of regenerated cartilage. Successful completion of this R21 project offers a paradigm shift in cartilage regeneration, with the potential clinical impact of introducing a reproducible, low-cost, material-only device capable of regenerating hyaline cartilage for patients suffering from knee cartilage injuries, the biomaterials field impact of a flagship chondroinductive peptide that others can easily incorporate into their own novel materials, and a lasting impact by opening a new avenue of investigation worldwide in peptide discovery approaches for chondrogenesis.