Collagen–β-TCP conjugated PCL biocomposites for bone tissue regeneration: fabrication, physical properties, and cellular activities

Abstract

Biomedical scaffolds need to be designed to support high seeding efficiency and facilitate high cellular activities (proliferation and differentiation) of injected cells with appropriate mechanical properties. In this study, solid freeform fabricated/freeze-dried biocomposites were manufactured from mixtures of polycaprolactone (PCL), collagen-I, and β-tricalcium phosphate (β-TCP). Without the use of any chemical solvents, the mixtures of collagen and β-TCP developed into micro-sized fibrous networks within various porous structures (average pore size = 313, 486, and 996 μm) consisting of micro-sized PCL struts. Although very small amounts of collagen (0.05 wt%) and β-TCP (0.05 wt%) were accommodated in the biocomposites, various biological analyses (seeding efficiency, live-dead fluorescence images, MTT assay, and calcium deposition) of the biocomposites using osteoblast-like cells (MG63) showed significantly high cell seeding efficiency, cell proliferation, and calcium deposition without any loss of mechanical properties compared with a pure PCL scaffold. In particular, the biocomposite (BC-2) with a pore size of 486 μm showed interesting cellular activities (cell morphology/shape and calcium deposition) due to the favorable synergistic effect of the PCL pore structure and the bioactive materials (collagen and β-TCP).