Evaluation of a bioceramic-based nanocomposite material for controlled delivery of a non-steroidal anti-inflammatory drug

In this study, nanocomposite of 50wt% calcium sulfate and 50wt% nanocrystalline apatite was produced and its biocompatibility, physical and structural properties were compared with pure calcium sulfate (CS) cement. Indomethacin (IM), a non-steroidal anti-inflammatory drug, was also loaded on both CS and nanocomposite cements and its in vitro release was evaluated over a period of time. The effect of the loaded IM on basic properties of the cements was also investigated. Biocompatibility tests showed a partial cytotoxicity in CS cement due to the reduced number of viable mouse fibroblast L929 cells in contact with the samples as well as spherical morphologies of the cells. However, no cytotoxic effect was observed for nanocomposite cement and no significant difference was found between the number of the cells seeded in contact with this specimens and culture plate as control. Other results showed that the setting time and injectability of the nanocomposite cement was much higher than those of CS cement, whereas reverse result obtained for compressive strength. In addition, incorporation of IM into compositions slightly increased the initial setting time and injectability of the cements and did not change their compressive strength. While a fast IM release was observed from CS cement in which about 97% of the loaded drug was released during 48h, nanocomposite cement showed a sustained release behavior in which 80% of the loaded IM was liberated after 144h. Thus, the nanocomposite can be a more appropriate carrier than CS for controlled release of IM in bone defect treatments.