Zheng Li, Sun Jin, Li Bo, Zhou Wen, Fan Hongsong, Zhang Xingdong
The Medical and Scientific Research Center of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi - China and Engineering Research Centre in Biomaterials, Sichuan University, Chengdu, Sichuan - China.
J Appl Biomater Funct Mater. 2014 Jun 12;12(1):41-7. doi: 10.5301/JABFM.2012.9340.
For scaffolds in cartilage tissue engineering, it is the principle to design the materials with both favorable mechanical and biological property.
In this article, collagen hydrogels modified by two ways to improve mechanical strength were applied for in vivo cartilage reconstruction: one is collagen-alginate hydrogel (CAH) representative of mixture, the other is collagen hydrogel crosslinked by genipin (CGH). To investigate the biological activities of the two materials, it was designed as: scaffolds loaded with allogenous chondrocytes were encased in diffusion chamber, and then implanted subcutaneously in SD rats for 8 weeks.
Histologic, immunohistochemical, and RT-PCR results showed that collagen type Ⅱ and GAG, indicator of cartilage extracellular matrix (ECM) was highly expressed in constructs of chondrocyte-CAH. Significantly lower cell density and expression of cartilage specific protein were shown in constructs of chondrocyte-CGH than that in chondrocyte-CAH. This demonstrated that CAH may provide a more favorable environment for cartilage reconstruction. In addition, the model with diffusion chamber technique was viable for evaluation of scaffolds in vivo cartilage engineering in immunocompetent host. Instead, directly reconstruction of ectopic cartilage without diffusion chamber suffered from damaged tissue and less neo-cartilage matrix formed.
In conclusion, CAH is realistic as scaffold for in vivo cartilage tissue engineering with both satisfactory mechanical properties and biomimetic activity. And the model with diffusion chamber to reconstruct ectopic cartilage in immunocompetent animals is promising for evaluation of scaffolds. This study provided a new insight for in vivo cartilage tissue engineering.
对于软骨组织工程中的支架，设计兼具良好力学性能和生物学性能的材料是基本原则。
在本文中，通过两种改善力学强度的方法改性的胶原水凝胶被应用于体内软骨重建：一种是作为混合物代表的胶原 - 海藻酸盐水凝胶（CAH），另一种是由京尼平交联的胶原水凝胶（CGH）。为了研究这两种材料的生物学活性，设计如下：将负载同种异体软骨细胞的支架包裹在扩散室中，然后皮下植入SD大鼠体内8周。
组织学、免疫组织化学和RT - PCR结果表明，软骨细胞 - CAH构建体中软骨细胞外基质（ECM）的指标Ⅱ型胶原和糖胺聚糖（GAG）高表达。软骨细胞 - CGH构建体中的细胞密度和软骨特异性蛋白表达明显低于软骨细胞 - CAH构建体。这表明CAH可能为软骨重建提供更有利的环境。此外，扩散室技术模型对于评估免疫活性宿主中体内软骨工程的支架是可行的。相反，没有扩散室的异位软骨直接重建会出现组织损伤且形成的新软骨基质较少。
总之，CAH作为体内软骨组织工程的支架是切实可行的，具有令人满意的力学性能和仿生活性。并且在免疫活性动物中使用扩散室重建异位软骨的模型对于支架评估具有前景。本研究为体内软骨组织工程提供了新的见解。
