Synthesis and characterization of mesoporous HA/GO nanocomposite in the presence of chitosan as a potential candidate for drug delivery

HA is a suitable material for the drug delivery due to its unique properties (including high biodegradation, bioactivity, and biocompatibility). Therefore, in recent years, many studies have been conducted in this field. Nevertheless, some restrictions like rapid drug release and low drug loading capacity are seen in former studies. The researchers suggested that these limitations can be addressed by modifying the producing procedure of HA and the augmentation of various materials for delaying drug release. Hence, novel mesoporous HA/GO nanocomposites were prepared through the chemical precipitation method in the presence of chitosan. HA nanoparticles and HA/GO nanocomposites were analyzed by several techniques including FT-IR, XRD, FE-SEM, TEM, BET, and TGA. In addition, the loading of naproxen and release behavior (pH = 7.4 and T = 37 degrees C) of the prepared samples were studied by UV-vis spectrophotometry. Our outcomes revealed that the crystalline size of the synthesized samples was in the range of 38-45 nm. The morphological structure analysis through FE-SEM and TEM analyses proved that HA/GO nanocomposites had a rod-like structure, and the morphological change in the HA/GO nanocomposites confirms that GO sheets and HA nanoparticles were successfully incorporated and synthesized nanocomposites with size less 50 nm. The mesoporous structure of the prepared samples was confirmed by BET analysis with an average pore diameter in a range of 15-50 nm and BET surface area of 14-33 m(2)/g. This can be considered as a very attractive characteristic of the prepared samples for drug delivery purposes. The ability of nanocomposites for naproxen delivery was analyzed as a drug delivery model under in vitro condition. With increasing weight ratio of GO, the percentage of drug loading has increased, so that for the HA/GO-0.3 g nanocomposite where the GO amount was at its maximum level, percentage of encapsulation efficiency (EE %) and percentage of drug loading capacity (LC %) 90.8% and 40.51% were obtained, respectively. Naproxen release studies in PBS showed that initial release for all samples occurred within the first 24 h, and subsequently the release rate was reduced gradually up to approximately 14 day. Under optimal situation, the synthesized nanocomposite with the maximum level of GO could maintain 56.2% of naproxen loaded after 14 days, which resulted from some drug molecules embedded deeply in HA/GO-0.3 g nanocomposite with more Go layers. Therefore, the results revealed that the HA/GO nanocomposites with the high loading efficiency and stable release capacity can be good candidates for sustained drug release.