3D printed porous titanium filled with mineralized UV-responsive chitosan hydrogel promotes cell proliferation and osteogenesis in vitro

The modification of 3D printed porous titanium (Ti), especially for the internal pore structure, is critical and has received more attention to promoting its osteogenesis for clinical use. Ultra-violet (UV) responsive chitosan (CSMA), as an injectable filling material, was firstly incorporated into porous Ti, and then CSMA was in-situ mineralized by carbon oxide (CO2) diffusion (CSMA/CaCO3). Their physical-chemical and biological properties were investigated in vitro. CaCO3 crystals within CSMA hydrogels were successfully deposited into pores of porous Ti, which exhibited favorable biocompatibility. Ti implants filled with CSMA/CaCO3 promoted adhesion and proliferation of bone mesenchymal stem cells (BMSCs). Moreover, Ti implant filled CSMA/CaCO3 hydrogels could increase alkaline phosphatase (ALP) activities, up-regulate osteopontin (OPN) and osteocalcin (OCN) expression levels, and enhance extracellular mineralization. 3D printed porous Ti filled with mineralized UV-responsive chitosan hydrogel could promote proliferation and osteogenesis of BMSCs, and have great potential for the modification of porous Ti implants in bone tissue engineering.