Construction of a drug-containing microenvironment for in situ bone regeneration

Abstract

The construction of bone scaffolds to treat bone defects caused by infection is a major challenge because such bone scaffolds need to both prevent infection from recurring and regenerate bone defects. To this end, we constructed bioactive glass (BG)-coated, hierarchical porous tricalcium phosphate (TCP) ceramics as both bone scaffolds and drug delivery devices to treat S. aureus-infected bone defects. In vitro simulation experiments confirmed that the as-prepared porous ceramics could construct a dynamic microenvironment, in which the concentration of the released antibiotics and calcium ions always changed and an apatite layer could grow on the ceramic surfaces. In vitro experiments demonstrated that antibiotic-loaded ceramics possessed good cytocompatibility and the microenvironment established by the antibiotic-loaded ceramics could mediate the osteogenic commitment of mesenchymal stem cells (MSCs), and at the same time, the antibiotic-loaded ceramics presented excellent and relatively-lasting antibacterial activity. In vivo experiments demonstrated that the antibiotic-loaded ceramics not only could prevent the S. aureus-infected bone defects from recurring, but also could boost the endogenous regeneration of bone.