Modifying of physical, biodegradation, drug delivery characteristics of bioactive borophosphate glass by addition of molybdenum

Abstract

In this study, high valence MoO3 was added to bioactive glass based on (50-x) P2O5 - 20 B2O3 – 20 CaO - 10 Na2O (x = 0, 5, 10–15 mol. %; the corresponding samples encoded as 0-Mo, 5-Mo, 10-Mo, and 15-Mo) to modify its physical, biodegradation, drug delivery properties. The glasses were prepared via melt-quenching process. The obtained glasses were analyzed by XRD, FTIR, SEM, Raman, and zeta potential (-42, - 31.8, - 34.5, and - 26.4 mV for 0-Mo, 5-Mo, 10-Mo, and 15-Mo, respectively). The in vitro bioactivity and biodegradation were examined in the simulated body fluid (SBF). The glasses were checked for ability for drug delivery by using ciprofloxacin (CIP) antibiotic as a drug model to attain an anticipated therapeutic response to avoid infections, and the drug release kinetic was studied by fitting the release data with Higuchi and Hixon-Crowell models. Finally, the antibacterial activity of the glasses conjugated with drug and drug-free glasses was tested against gram positive bacteria (Streptococcus aureus), gram negative bacteria (Escherchia coli) and Pathogenic yeast (Candida albicans). The results showed that the glasses were characterized by amorphous structure, and it showed a good bioactivity after immersion in SBF. Moreover, the results presented that addition of molybdenum increased the degradation rate of the glasses and affected their surface charge to less negative. In addition, it increased the drug loading efficiency and drug release rate, where 11.2 %, 56.9 %, 75.4 %, and 83.6 % of the drug released from 0-Mo, 5-Mo, 10-Mo, and 15-Mo, respectively, at the end of incubation time. The drug release occurred by combined diffusion and dissolution mechanism. Finally, antibacterial activity showed that drug-free glasses possessed antibacterial activity against the bacterial, meanwhile the antibacterial activity increased by loading CIP on the glass particles. In conclusion, different physical properties, as well as biodegradation and drug release can be tailored by addition of molybdenum. On the other hand, the prepared glasses are expected to be used successfully as multifunctional bone grafting materials.