Porous polycaprolactone/nanohydroxyapatite tissue engineering scaffolds fabricated by combining NaCl and PEG as co-porogens: structure, property, and chondrocyte-scaffold interaction in vitro.

In this study, porous polycaprolactone/nanohydroxyapatite (PCL/nHA) composite scaffolds were fabricated using a modified melt-molding/leaching technique, by the combination of salt particulate (NaCl) and water-soluble polymer (PEG) as co-porogens. The porogens were kept at a constant proportion of 70% in the blends but varied in the NaCl/PEG ratio and the PEG variety to generate PCL/nHA scaffolds with various pore architectures. The resultant composite scaffolds were investigated on their morphologies, physicochemical properties, mechanical properties, and in vitro degradation. The cell-scaffold interactions were evaluated in vitro using chondrocyte. Generally, the PCL/nHA scaffolds exhibited multimodal pore morphologies consisting of macropores and interconnected micropores, created by the extraction of NaCl particulate and continuous PEG phase. The evolution of porogens led to much effect on the overall pore architecture of the scaffolds; subsequently, their physiochemical and mechanical properties and degradation behaviors, as well as the cell binding and proliferation. The PCL/nHA scaffold prepared from NaCl/PEG 4000 (20/50) presented more macropores (>50 μm) with interconnectivity and showed higher strength and improved bioactivity than the others. All of these results suggest promising potentials of PCL/nHA scaffolds developed in this study desired for cartilage tissue engineering.