Extracellular matrix coated three-dimensional-printed polycaprolactone scaffolds containing curcumin for cartilage tissue engineering applications

Extracellular matrix (ECM) is widely used for clinical purposes in tissue engineering (TE). Since ECM does not have favorable mechanical properties, its use has been limited. Therefore, it is helpful to use synthetic polymers such as polycaprolactone (PCL) to improve the mechanical properties of ECM-based scaffolds. PCL scaffolds were prepared via the three-dimensional (3D) printing method. Cartilaginous ECM was obtained from bovine femur, and then it was decellularized and solubilized. PCL scaffolds were functionalized using 1,6-hexanediamine; consequently, the scaffolds were coated with solubilized decellularized ECM (SDECM) using two types of crosslinkers; namely, N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) and genipin. Genipin-crosslinked SDECM-coated (PCL/ECM-Gen) scaffolds and EDC/NHS-crosslinked SDECM-coated (PCL/ECM-EN) scaffolds were characterized by different tests. Following loading the curcumin (Cur) on the scaffolds, the Cur release rate was investigated. Finally, human chondrocyte cells were cultured on the scaffolds to explore cell viability, cell attachment, and histological studies. Following functionalization via amine groups, 5% SDECM was used to coat the scaffolds, and this increased the wettability and cell viability of the PCL. Genipin crosslinked and coated the SDECM more efficiently compared to the EDC/NHS and led to lower porosity, water absorption capacity, degradation rate, higher cell proliferation, and cell attachment. Genipin-crosslinked Cur-loaded (PCL/ECM-Gen + Cur) scaffolds showed higher cell viability but lower antibacterial activity compared to EDC/NHS-crosslinked Cur-loaded (PCL/ECM-EN + Cur) scaffolds, which may indicate EDC/NHS-induced cytotoxicity. This study elucidates the value of PCL/ECM-Gen + Cur scaffolds as highly biocompatible scaffolds that can be considered a promising tool for cartilage TE applications.