Novel carboxymethyl chitosan-graphene oxide hybrid particles for drug delivery

We describe an electrostatic droplet generation method to prepare a novel carboxymethyl chitosan-graphene oxide hybrid particles for delivery purpose. Under an adjustable electrostatic field, graphene oxide and carboxymethyl chitosan mixed solution was sprayed as uniform micro-droplets, which were solidified as particles in CaCl₂ solution. Such hybrid particles are wished to have excellent stability in saline solution, and better delivery properties than pristine carboxymethyl chitosan particles. The effects of micro-droplets generation conditions on particles formation were systematically investigated. At conditions of 40 mg/ml of carboxymethyl chitosan, 2 mg/ml of graphene oxide, 3 ml/h of feed speed, electrostatic field parameters was 9 kV and 20 cm, uniformly sized carboxymethyl chitosan-graphene oxide particles in the diameter range of 250-300 μm was successfully prepared. In NaCl saline, these particles could maintain stable for at least a week, while pristine carboxymethyl chitosan particles quickly collapsed within an hour. The results of loading experiments showed that carboxymethyl chitosan-graphene oxide particles could effectively adsorb gatifloxacin, ofloxacin, bovine serum albumin, lysozyme, doxorubicin hydrochloride. And gatifloxacin was chosen as a model drug to study the exact effect of graphene oxide content on the loading and release properties. In 40:2 group, the highest loading capacity of 0.45 ± 0.19 mg/mg was achieved, and also a good sustained release was available. Above all, we believed that carboxymethyl chitosan-graphene oxide particles as a versatile carrier, has great potential in Medicine and Pharmacy.