Hannouche D, Terai H, Fuchs J R, Terada S, Zand S, Nasseri B A, Petite H, Sedel L, Vacanti J P
Laboratory for Tissue Engineering and Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
Tissue Eng. 2007 Jan;13(1):87-99. doi: 10.1089/ten.2006.0067.
Fabrication of implantable cartilaginous structures that could be secured in the joint defect could provide an alternative therapeutic approach to prosthetic joint replacement. Herein we explored the possibility of using biodegradable hydrogels in combination with a polyglycolic acid (PGA) scaffold to provide an environment propitious to mesenchymal stem cells (MSCs) chondrogenic differentiation. We examined the influence of type I collagen gel and alginate combined with PGA meshes on the extracellular matrix composition of tissue-engineered transplants. MSCs were isolated from young rabbits, expanded in monolayers, suspended in each hydrogel, and loaded on PGA scaffolds. All constructs (n=48) were cultured in serum-free medium containing transforming growth factor beta-1, under dynamic conditions in specially designed bioreactors for 3-6 weeks. All cell-polymer constructs had a white, shiny aspect, and retained their initial size and shape over the culture period. Their thickness increased substantially over time, and no shrinkage was observed. All specimens developed a hyalin-like extracellular matrix containing glycosaminoglycans (GAGs) and type II collagen, but significant differences were observed among the three different groups. In PGA/MSCs and collagen-PGA/MSCs constructs, the cell growth phase and the chondrogenic differentiation phase of MSCs occurred during the first 3 weeks. In alginate-PGA/MSCs constructs, cells remained round in the hydrogel and cartilage extracellular matrix deposition was delayed. However, at 6 weeks, alginate-PGA/MSCs constructs exhibited higher contents of GAGs and lower contents of type I collagen. These results suggest that the implied time for the transplantation of in vitro engineered constructs depends, among other factors, on the nature of the scaffold envisioned. In this study, we demonstrated that the use of a composite hydrogel-PGA scaffold supported the in vitro growth of implantable cartilaginous structures cultured in a bioreactor system.
制造能够固定在关节缺损处的可植入软骨结构，可为人工关节置换提供一种替代治疗方法。在此，我们探索了将可生物降解水凝胶与聚乙醇酸（PGA）支架结合使用的可能性，以提供有利于间充质干细胞（MSCs）软骨形成分化的环境。我们研究了I型胶原蛋白凝胶和藻酸盐与PGA网片结合对组织工程移植物细胞外基质组成的影响。从幼兔中分离出MSCs，在单层中扩增，悬浮于每种水凝胶中，并加载到PGA支架上。所有构建体（n = 48）在含有转化生长因子β-1的无血清培养基中，在专门设计的生物反应器的动态条件下培养3至6周。所有细胞-聚合物构建体均呈现白色、有光泽的外观，并且在培养期间保持其初始大小和形状。它们的厚度随时间显著增加，未观察到收缩。所有标本均形成了含有糖胺聚糖（GAGs）和II型胶原蛋白的透明样细胞外基质，但在三个不同组之间观察到了显著差异。在PGA/MSCs和胶原蛋白-PGA/MSCs构建体中，MSCs的细胞生长阶段和软骨形成分化阶段在前3周发生。在藻酸盐-PGA/MSCs构建体中，细胞在水凝胶中保持圆形，软骨细胞外基质沉积延迟。然而，在6周时，藻酸盐-PGA/MSCs构建体表现出更高的GAGs含量和更低的I型胶原蛋白含量。这些结果表明，体外工程构建体的移植所需时间除其他因素外，还取决于所设想支架的性质。在本研究中，我们证明了使用复合水凝胶-PGA支架支持了在生物反应器系统中培养的可植入软骨结构的体外生长。
