Enhanced Osteogenesis of Injectable Calcium Phosphate\nBone Cement Mediated by Loading Chondroitin Sulfate

Abstract

Toward\nrepairing critical-sized bone defects, calcium phosphate\ncement (CPC) has been well recognized as a fairly promising bone graft\nbecause of its properties of injectability, self-setting, biocompatibility,\nand osteoconductivity. However, poor osteogenic capacity of CPC still\nlimits its applications for meeting the demands of bone healing. In\nthis work, chondroitin sulfate (CS), as an important component of\nthe extracellular matrix network, was introduced into CPC to enhance\nits osteogenesis ability. Incorporation of CS had no evident effect\non the phase, morphology, apparent porosity, and compressive strength\nof hydrated cement products, but it notably enhanced the injectability\nand improved the antiwashout property of the cement pastes. CS was\nable to be sustainably released from CS-CPCs in a CS-dose-dependent\nmanner and supposed to have a long-term release potential for constant\nbiological stimulation. CS-CPCs markedly accelerated the preferential\nadsorption of fibronectin. Furthermore, CS-CPCs significantly improved\nthe adhesion, proliferation, and osteogenic differentiation of bone\nmesenchymal stem cells, which was synergistically mediated by the\nadhesion events of cells on the hydrated cements and the stimulation\neffects of CS molecules. Herein, utilization of CS is supposed to\nendow injectable calcium phosphate bone cements with enhanced osteogenic\ncapacity and suitable physicochemical properties for numerous promising\northopedic applications.