Engineered knee meniscus construct: understanding the structure and impact of functionalization in 3D environment

The structural complexity of human knee meniscus warrants a suitable 3D microenvironment for its successful regeneration. For this, 3D porous poly-ε-caprolactone (PCL) scaffold structures were prepared using freeze drying method (lyophilization). PCL was dissolved in different weight percentages (10, 15, 20% w/v, coded as P10, P15 and P20, respectively) in acetone and lyophilized to develop 3D porous structures. The scaffolds were studied for their morphological, mechanical and functional properties. Compression tests were performed to understand their compressive properties and structural integrity. Results indicate that P10 is most suitable considering the highest porosity (above 85%), uniform pore distribution, better resiliency and less than 40% compression at a load of 30 kg/cm2 for 1 min. Further, the effect of a unique combination of biomolecule (UCM) functionalization in 3D PCL scaffold (P10) on human meniscal cell attachment, growth and proliferation was studied in detail. The developed scaffolds were also characterized for dynamic mechanical properties and compared with native human meniscal tissue properties. The primary human meniscus cell attachment, growth and proliferation on to the scaffolds were studied and analyzed using SEM and Hoechst staining experiments. Extracellular matrix secretion (glycosaminoglycans and collagen) in the cell culture medium was estimated. UCM-functionalized PCL 3D porous scaffold, P10 showed better cell attachment and proliferation indicating its potential for meniscus tissue engineering applications.