Comparison of chondrogenesis in static and dynamic environments using a SFF designed and fabricated PCL-PEO scaffold

Abstract

A tssue engineering approach combining the scaffold/cell/matrix aspires to be a suitable alternative for current cartilage injury treatment modalities to produce a functional cartilage graft. Scaffolds synthesised from elastomeric materials and fabricated by a rapid prototyping technique were tested and investigated as a potential candidate for cartilage tissue engineering. The purpose of this study is to investigate the influence of scaffold internal architectures, matrix composition and dynamic environmental conditions on the final outcome of the scaffold-cell construct. PCL-PEO scaffolds were fabricated with 0°–90° and 0°–45° lay-down patterns with porosity values of 60% and 71% respectively. They were seeded with 500,000 porcine articular chondrocytes along with two different hydrogels, i.e. alginate and alginate/thrombin, and chondrocyte behaviour was studied. Furthermore, scaffold-cell constructs were cultured dynamically using the spinner flask method for 6 weeks. Porosity and surface-to-volume ratios were different for scaffolds with diverse geometry. The 0°–45° pattern scaffold showed significantly increased cell numbers and extracellular matrix proteins such as collagen-II compared to the 0°–90° scaffolds. The alginate/thrombin matrix encapsulated more chondrocytes compared to the alginate matrix alone. Cells were found to be viable and actively proliferating after 6 weeks of culture, maintaining the rounded chondrocyte phenotype in the matrix. Cell number, metabolic activity and extracellular matrix, such as collagen II, were produced significantly more in the dynamic environment compared to the static environment.