Fabrication of injectable calcium sulfate bone graft material.

Calcium sulfate (CaSO4), as a commonly used implanting material, shows good biocompatibility, biodegradability, osteoconductivity and mechanical properties. Studies about using CaSO4 as bone filler for the treatment of bone defects are reported now and then, but the fabrication of injectable implant was hardly studied. In this study, calcium sulfate hemihydrate (CSH), as the basic material, was incorporated with a cellulose derivative, poly(ethylene glycol) (PEG), calcium sulfate dehydrate (CSD) crystal coated with PEG (P-CSD), and a certain amount of water to form injectable CaSO4 bone fillers. The structure of the bone fillers with different compositions was analyzed with scanning electron microscopy (SEM), infrared spectroscopy (IR) and X-ray diffraction (XRD). The effects of additives such as P-CSD, CSD, PEG and cellulose derivative on setting time, water absorption ability, mechanical properties and structure of the injectable bone fillers were studied. The in vitro degradation test showed that the injectable bone fillers have appropriate degradation time in phosphate-buffered solution (PBS), and they can maintain integrity throughout the degradation process. In vitro cell culture and preliminary animal model experiments demonstrated that the bone fillers do not exhibit a deleterious effect on cell viability and can hasten bone growth in bone defect model. (C) Koninklijke Brill NV, Leiden, 2010