On demand electrochemical release of drugs from porous reduced graphene oxide modified flexible electrodes
Despite the advantages of an electrochemical control of drug release, only a handful of electrochemical-based release systems have been developed so far. We report herein on the development of an electrochemically activable platform for on-demand delivery of drugs. It is based on flexible gold thin film electrodes coated with porous reduced graphene oxide (prGO) nanosheets onto which the drug of interest has been integrated beforehand. Two different drugs are investigated here: ondansetron hydrochloride (ODS), a selective 5-HT3 receptor antagonist, used for preventing nausea and vomiting caused by chemotherapy and radiotherapy and ampicillin (AP), an antibiotic to prevent and treat a number of bacterial infections such as respiratory tract infections, urinary tract infections, meningitis. In the case of ODS, application of a negative potential bias of - 0.8V results in a sustained slow ODS release with an ODS flux of 47 µg cm-2 h-1. In the case of ampicillin, we show that polyethyleneimine modified prGO (prGO/PEI) is an extremely efficient matrix for the loading with AP. Upon the application of + 0.8 V, 24 % of AP can be released from the electrical interface in a time span of 2h. The released AP kept its antibacterial activity as demonstrated by antimicrobial tests. These examples illustrate the major benefits of the developed approach for biomedical applications.