Abstract

Growth factors (GFs) are soluble proteins extracellular that control a wide range of cellular processes as well as tissue regeneration. While transforming growth factor beta-1 (TGF-β1) promotes chondrogenesis, its medical use is restricted by its potential protein instability, which necessitates high doses of the protein, which can result in adverse side effects such as inefficient cartilage formation. In this work, we have developed a novel hydrogel composite based on the polymer, cross-linked thiolated chitosan; TCS and carboxymethyl cellulose; CMC (TCS/CMC) hydrogel system was utilized as injectable TGF-β1 carriers for cartilage tissue engineering applications. Rheological measurements showed that the elastic modulus of TCS/CMC hydrogels with an optimized CMC concentration could reach around 2.5 kPa or higher than their respective viscous modulus, indicating that they behaved like strong hydrogels. Crosslinking significantly alters the overall network distribution, surface morphology, pore size, porosity, gelation time, swelling ratio, water content, and in vitro degradation of the TCS/CMC hydrogels. TCS/CMC hydrogels maintain more than 90% of their weight and retain their original form after 21 days. TGF-β1 released marginally from TCS/CMC hydrogels as incubation time increased, up to 21 days, with around 18.6 ± 0.9% of the drug stored inside the TCS/CMC hydrogels. On day 21, BMSC treated with TGF-β1 in medium or TGF-β1-loaded TCS/CMC hydrogels grew faster than the other groups. For in vivo cartilage repair, full-thickness cartilage defects were induced on rat knees for 8 weeks. The optimal ability of this novel TGF-β1-loaded TCS/CMC hydrogel system was further demonstrated by histological analysis, resulting in a novel therapeutic strategy for repairing articular cartilage defects.

摘要

生长因子 (GFs) 是细胞外可溶性蛋白质，可控制广泛的细胞过程以及组织再生。虽然转化生长因子 β-1 (TGF-β1) 促进软骨形成，但其医学用途受到其潜在的蛋白质不稳定性的限制，这需要高剂量的蛋白质，这可能导致不利的副作用，例如软骨形成效率低下。在这项工作中，我们开发了一种基于聚合物交联硫醇化壳聚糖的新型水凝胶复合材料；TCS和羧甲基纤维素；CMC (TCS/CMC) 水凝胶系统被用作可注射的 TGF-β1 载体，用于软骨组织工程应用。流变测量表明，优化 CMC 浓度的 TCS/CMC 水凝胶的弹性模量可以达到 2 左右。5 kPa 或高于它们各自的粘性模量，表明它们表现得像强水凝胶。交联显着改变了整体网络分布、表面形态、孔径、孔隙率、凝胶时间、溶胀率、水含量和TCS/CMC 水凝胶的体外降解。TCS/CMC 水凝胶保持其重量的 90% 以上，并在 21 天后保持其原始形状。随着孵育时间的增加，TGF-β1 从 TCS/CMC 水凝胶中略微释放，最多 21 天，大约 18.6 ± 0.9% 的药物储存在 TCS/CMC 水凝胶内。在第 21 天，在培养基或负载 TGF-β1 的 TCS/CMC 水凝胶中用 TGF-β1 处理的 BMSC 比其他组生长得更快。对于体内软骨修复，在大鼠膝盖上诱导全层软骨缺损 8 周。组织学分析进一步证明了这种新型负载 TGF-β1 的 TCS/CMC 水凝胶系统的最佳性能，从而为修复关节软骨缺损提供了一种新的治疗策略。