Jonnalagadda John B, Rivero Iris V, Dertien Janet S
a Department of Industrial Engineering , Texas Tech University , Lubbock , TX 79409 , USA.
J Biomater Sci Polym Ed. 2015;26(7):401-19. doi: 10.1080/09205063.2015.1015864. Epub 2015 Mar 12.
In this study, poly(e-caprolactone)/polyglycolic acid (PCL/PGA) scaffolds for repairing articular cartilage were fabricated via solid-state cryomilling along with compression molding and porogen leaching. Four distinct scaffolds were fabricated using this approach by four independent cryomilling times. These scaffolds were assessed for their suitability to promote articular cartilage regeneration with in vitro chondrocyte cell culture studies. The scaffolds were characterized for pore size, porosity, swelling ratio, compressive, and thermal properties. Cryomilling time proved to significantly affect the physical, mechanical, and morphological properties of the scaffolds. In vitro bovine chondrocyte culture was performed dynamically for 1, 7, 14, 28, and 35 days. Chondrocyte viability and adhesion were tested using MTT assay and scanning electron microscopy micrographs. Glycosaminoglycan (GAG) and DNA assays were performed to investigate the extracellular matrix (ECM) formation and cell proliferation, respectively. PCL/PGA scaffolds demonstrated high porosity for all scaffold types. Morphological analysis and poly(ethylene oxide) continuity demonstrated the existence of a co-continuous network of interconnected pores with pore sizes appropriate for tissue engineering and chondrocyte ingrowth. While mean pore size decreased, water uptake and compressive properties increased with increasing cryomilling times. Compressive modulus of 12, 30, and 60 min scaffolds matched the compressive modulus of human articular cartilage. Viable cells increased besides increase in cell proliferation and ECM formation with progress in culture period. Chondrocytes exhibited spherical morphology on all scaffold types. The pore size of the scaffold affected chondrocyte adhesion, proliferation, and GAG secretion. The results indicated that the 12 min scaffolds delivered promising results for applications in articular cartilage repair.
在本研究中,通过固态冷冻研磨结合压缩成型和致孔剂浸出法制备了用于修复关节软骨的聚(ε-己内酯)/聚乙醇酸(PCL/PGA)支架。通过四个独立的冷冻研磨时间,使用这种方法制备了四种不同的支架。通过体外软骨细胞培养研究评估这些支架促进关节软骨再生的适用性。对支架的孔径、孔隙率、溶胀率、压缩性能和热性能进行了表征。结果证明,冷冻研磨时间对支架的物理、机械和形态性能有显著影响。对牛软骨细胞进行了动态体外培养,培养时间分别为1、7、14、28和35天。使用MTT法和扫描电子显微镜照片测试软骨细胞的活力和黏附情况。分别进行糖胺聚糖(GAG)和DNA检测以研究细胞外基质(ECM)的形成和细胞增殖情况。所有类型的PCL/PGA支架均显示出高孔隙率。形态分析和聚环氧乙烷的连续性表明存在相互连接的孔的共连续网络,其孔径适合组织工程和软骨细胞向内生长。虽然平均孔径减小,但随着冷冻研磨时间的增加,吸水率和压缩性能增加。冷冻研磨12、30和60分钟的支架的压缩模量与人关节软骨的压缩模量相当。随着培养时间的延长,活细胞数量增加,同时细胞增殖和ECM形成也增加。在所有类型的支架上,软骨细胞均呈现球形形态。支架的孔径影响软骨细胞的黏附、增殖和GAG分泌。结果表明,冷冻研磨12分钟的支架在关节软骨修复应用中取得了有前景的结果。