polyethylene glycol-graphene oxide modified with mesalazine; synthesis, characterization, and in-vitro drug releasing investigation

Regarding the importance of targeted delivery of pharmacies, a novel drug delivery system was designed by mesalazine (mes) anchoring on graphene oxide (go) modified with polyethylene glycol (peg) to obtain 2.6 mmol mes on 1 g of go-peg. the new compound was produced through esterification reactions of go with peg and subsequent esterification with mes. the nano drug was characterized with common analysis methods including raman, ft-ir, uv-vis, energy dispersive x-ray, x-ray diffraction, and transmission electron microscopy. the in vitro mes releasing from the composite was evaluated at two phs of 3.5 and 7.4 for simulation of the gastric and intestine conditions. it was found that the compound is more stable in acidic media and slowly releases mes at ph=4. the reason for this phenomenon is considered the ester bonds are produced in acidic media and have not been hydrolyzed in these conditions. the initial results of in vitro experiments indicated that the new drug would be a promising candidate for use in vivo.