Sonochemical Preparation Of Stimuli-responsive Graphene Microcapsules

Development of effective drug delivery systems for biomedical applications has been investigated intensively over the past decades.Among the plenty of drug delivery systems,drug delivery systems with targeting and stimuli-responsive properties,have outstanding advantages in tumor therapies,due to the drug could be carried to the targeted site rapidly by the magnetic and molecular targeting ability and the drug could be controlled to release by some smart responsiveness(temperature-responsive,pH-responsive,redox-responsive and so on).In this paper,the research focuses on the fabrication of multifunctional graphene oxide-based capsules via sonochemical method and their performances.The graphene oxide-based drug-loaded capsules with different properties have been synthesized using graphene oxide,chitosan,folate molecular,magnetic nanoparticles and so on.In addition,the drug loading capacity and control drug release behaviors have been investigated.1.The pH and redox dual-responsive magnetic graphene oxide microcapsules(MGOMCs)have been prepared successfully by a simple sonochemical method.The disulfide bonds cross-linked the wall of MGOMCs were formed from the hydrosulfuryl on the surface of thiolated graphene oxide(TG).The oleic acid modified Fe3O4 nanoparticles(OA-Fe3O4 NPs)and C6(a model of hydrophobic drugs)which dispersed in the oil phase were encapsulated in the microcapsules successfully.Furthermore,the influences of ultrasonic power,ultrasonic time,concentration of TG aqueous solution and oil-water ratio on the morphologies and sizes of MGOMCs were investigated in detail.Finally,the magnetic properties and smart responsive ability have been studied.2.The folic acid functionalized multistimuli-responsive magnetic graphene oxide-based nanocapsules(FA-MRMGONCs)have been synthesized successfully via sonochemical method.The TG and FA functionalized thiolated chitosan(FA-CS-SH)in aqueous phase were cross-linked to form the shell of nanocapsules.The OA-Fe3O4 NPs and C6 in the oil phase were encapsulated into the nanocapsules.The researches demonstrate that FA-MRMGONCs have the following characteristics: 1)The FA-MRMGONCs showed a nice molecular and magnetic targeting ability due to the FA molecules which were fixed on the wall of nanocapsules and the OA-Fe3O4 NPs which were loaded into the nanocapsules;2)The shell of obtained nanocapsules could protect the drugs which were loaded into the nanocapsules and avoid the leak of drug during transportation.3)The as-synethized FA-MRMGONCs possess excellect photothermal properties and photo responsiveness,which demonstrated that the nanocapsules could be a promising candidate for tumor photothermal therapy.4)Because the shell of FA-MRMGONCs was cross-linked by disulfide bonds,the nanocapsules had a certain reductive responsiveness and can effectively control the release of the inner drugs.