Antibiotic-containing biodegradable bead clusters with porous PLGA coating as controllable drug-releasing bone...

The construction of inorganic bone fillers with a suitable degradation period to match the new bone growth is an urgent task since most bone fillers have an either too fast or slow degradation rate. Calcium sulfate, as a commonly used implanting material, shows good biocompatibility, biodegradability, osteoconductivity and mechanical properties. However, its degradation rate and the drug-release rate are too rapid to meet the requirements for clinical application. In this paper, calcium sulfate bead clusters (CSBC), with or without loaded drug, were prepared; and two kinds of coatings, porous or nonporous, were deposited on the surface of the beads to extend the degradation and the drug release period. The results show that poly(lactic acid-glycolic acid) (PLGA) coatings, incorporated with different porogens can form in situ porous coatings that obviously lengthen the degradation period of the beads from 30 days to around 60-90 days. Consequently, the drug-release rate was significantly reduced, and the release period increased from about 10 days to over 50 days.