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 (CO 2 ) diffusion (CSMA/CaCO 3 ). Their physical-chemical and biological properties were investigated in vitro . CaCO 3 crystals within CSMA hydrogels were successfully deposited into pores of porous Ti, which exhibited favorable biocompatibility. Ti implants filled with CSMA/CaCO 3 promoted adhesion and proliferation of bone mesenchymal stem cells (BMSCs). Moreover, Ti implant filled CSMA/CaCO 3 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.