Effect of gamma irradiation on drug releasing from nano-bioactive glass.

In this work, we studied the effect of gamma irradiation on nano-bioactive glass (NBG) structure, bioactivity, drug loading efficiency, and drug release kinetic. Gamma irradiation was mainly introduced as a safe and cheap method to tailor the drug loading and release efficiencies. NBG was investigated before and after gamma irradiation with two doses 25 and 50 kGy. Vancomycin antibiotic was used as a drug model, and different kinetic models (first order, Higuchi, Hixson-Crowell, and Baker-Lonsdale models) were used to study the mechanism of drug release. It was found that G25 sample showed the lowest affinity for vancomycin adsorption, but it showed the highest release rate. Also, vancomycin was released from all samples by diffusion mechanism from spherically shaped carrier. On the other hand, the bioactivity of NBG was not altered by gamma irradiation; in contrary, newly formed apatite layers were more well-crystalline.