Novel phase separated polycaprolactone/collagen scaffolds for cartilage tissue engineering

Osteoarthritis is the leading cause of pain and disability worldwide. Despite treatment availability, fully functional and suitable long term treatments for large cartilage defects are yet to be sought. Cartilage tissue engineering provides an alternative treatment option with the potential of cartilage regeneration. Previously, scaffolds have been enhanced through coating with collagen type I, however, equal distribution of collagen and collagen penetration throughout the scaffold have been poor. Herein, this study aims to employ thermally induced phase separation to fabricate porous hybrid polycaprolactone (PCL)/collagen type I scaffolds, with equally distributed collagen type I throughout the scaffold. PCL/collagen scaffolds were produced using polycaprolactone, varying concentrations of collagen type I and acetic acid as the solvent. Scaffolds were seeded with chondrocytes for 14 days. Scaffolds possessed an interconnected and porous structure, which altered with an increase in collagen concentration. Collagen type I antibody staining revealed the presence of equally distributed collagen within the PCL fibres. A reduction in collagen type I concentration influenced the compressive properties of the PCL/collagen type 1 scaffolds. Specifically, 0.2% wt/vol concentration of collagen presented to have compressive properties similar to that of the native cartilage at 10% strain. All scaffolds allowed cell attachment and collagen scaffolds showed a greater number of viable chondrocytes after 14 days of culture, compared to PCL control. This study demonstrated the ability of fabricating PCL/collagen type I scaffolds which exhibit easily tuneable porosity and compressive properties. Further investigation on the long term feasibility of these scaffolds is warranted.