Tissue-engineered cartilage constructs using composite hyaluronic acid/collagen I hydrogels and designed poly(propylene fumarate) scaffolds
Tissue-engineered cartilage constructs using composite hyaluronic acid/collagen I hydrogels and designed poly(propylene fumarate) scaffolds
复制标题
DOI：
10.1089/ten.2006.0117
复制
发表时间：
2007-03-01
影响因子：
--
通讯作者：
Hollister, Scott
中科院分区：
文献类型：
--
作者：
Liao, Elly;Yaszemski, Michael;Hollister, Scott
我们的软骨组织工程支架方法结合了基于图像的设计和固体自由形式（SFF）制造，以创建用户定义参数的承重结构。在这项研究中，三维支架与立方体和椭圆形孔结构的制作使用聚（丙二醇富马酸酯）（PPF）。为了增加接种效率和细胞保留，使用水凝胶将细胞递送到支架中。本研究的第一个目的是评估复合透明质酸（HyA）和胶原蛋白I水凝胶的浓度，最好能够刺激蛋白多糖在猪软骨细胞在体外和体内的合成。第二个目的是评估由于孔几何形状和支架设计导致的细胞外基质产生的差异。对于体外评估，将软骨细胞包封在具有不同浓度HyA的胶原蛋白I水凝胶中。将水凝胶培养1周和2周，然后使用二甲基亚甲蓝测定法定量硫酸化糖胺聚糖（sGAG）含量。最能增加ECM合成的HyA浓度为5%HyA/胶原I，或0.23 mg/mL HyA。将体外实验的结果用作体内分析的培养参数。复合5%HyA/胶原蛋白I或胶原蛋白I的水凝胶用于种子软骨细胞到SFF制造的支架制成的PPF与设计的立方体或椭圆形的孔几何形状。将支架皮下植入免疫功能低下的小鼠体内4周。用番红O染色的切片的组织形态计量学分析用于定量支架中细胞沉积的ECM的量。接种有5%HyA/胶原水凝胶的支架具有显著更大的阳性番红O染色面积（约60%，相比之下，仅接种有胶原I水凝胶的支架为30%），表明更多数量的软骨细胞在异位环境中保留了它们的代谢活性。这些支架还具有比单独接种胶原I水凝胶的对应物更大的染色强度（对应于ECM中更大量的sGAG）。在支架孔设计之间未发现基质产生的显著差异。总的来说，这些结果表明，复合HyA水凝胶和设计的SFF支架的组合可以提供用于软骨修复的功能性组织工程化构建体，其在承重支架中具有增强的组织再生。
Our approach to cartilage tissue-engineering scaffolds combines image-based design and solid free-form (SFF) fabrication to create load-bearing constructs with user-defined parameters. In this study, 3-dimensional scaffolds with cubic and ellipsoidal pore architecture were fabricated using poly( propylene fumarate) (PPF). To increase seeding efficiency and cellular retention, hydrogels were used to deliver cells into the scaffolds. The first objective of this study was to evaluate the concentrations of composite hyaluronic acid (HyA) and collagen I hydrogels best able to stimulate proteoglycan synthesis in porcine chondrocytes in vitro and in vivo. The second objective was to evaluate the differences in extracellular matrix production due to pore geometry and scaffold design. For the in vitro assessment, chondrocytes were encapsulated in collagen I hydrogels with varying concentrations of HyA. Hydrogels were cultured for 1 and 2 weeks, and then the sulfated glycosaminoglycan (sGAG) content was quantified using a dimethyl-methylene blue assay. The concentration of HyA best able to increase ECM synthesis was 5% HyA/collagen I, or 0.23 mg/mLHyA. The results from the in vitro experiment were used as culture parameters for the in vivo analysis. Composite 5% HyA/collagen I or collagen I-only hydrogels were used to seed chondrocytes into SFF-fabricated scaffolds made of PPF with designed cubic or ellipsoidal pore geometry. The scaffolds were implanted subcutaneously in immunocompromised mice for 4 weeks. Histomorphometric analyses of sections stained with Safranin O were used to quantify the amount of ECM deposited by cells in the scaffolds. Scaffolds seeded with 5% HyA/collagen hydrogels had significantly greater areas of positive Safranin O staining (approximately 60%, compared with 30% for scaffolds with collagen I hydrogels only), indicating that greater numbers of chondrocytes retained their metabolic activity in the ectopic environment. These scaffolds also had greater stain intensities (corresponding to greater amounts of sGAG in the ECM) than their counterparts seeded with collagen I hydrogels alone. Significant differences in matrix production were not found between the scaffold pore designs. Overall, these results indicate that a combination of composite HyA hydrogels and designed SFF scaffolds could provide a functional tissue-engineered construct for cartilage repair with enhanced tissue regeneration in a load-bearing scaffold.