Smartphone-powered iontophoresis-microneedle array patch for controlled transdermal delivery

The incidence rate of diabetes has been increasing every year in nearly all nations and regions. The traditional control of diabetes using transdermal insulin delivery by metal needles is generally associated with pain and potential infections. While microneedle arrays (MAs) have emerged as painless delivery techniques, the integration of MA systems with electronic devices to precisely control drug delivery has rarely been realized. In this study, we developed an iontophoresis-microneedle array patch (IMAP) powered by a portable smartphone for the active and controllable transdermal delivery of insulin. The IMAP in situ integrates iontophoresis and charged nanovesicles into one patch, achieving a one-step drug administration strategy of “penetration, diffusion and iontophoresis”. The MA of the IMAP is first pressed on the skin to create microholes and then is retracted, followed by the iontophoresis delivery of insulin-loaded nanovesicles through these microholes in an electrically controlled manner. This method has synergistically and remarkably enhanced controlled insulin delivery. The amount of insulin can be effectively regulated by the IMAP by applying different current intensities. This in vivo study has demonstrated that the IMAP effectively delivers insulin and produces robust hypoglycemic effects in a type-1 diabetic rat model, with more advanced controllability and efficiency than delivery by a pristine microneedle or iontophoresis. The IMAP system shows high potential for diabetes therapy and the capacity to provide active as well as long-term glycemic regulation without medical staff care. A device developed by researchers in China uses a microneedle array to efficiently and painlessly deliver precise doses of insulin and can be used by patients without help from medical staff. The new system was developed by a team led by Xi Xie and Lelun Jiang of Sun Yat-Sen University. The array of microneedles is pressed against the skin to create micro-holes and then automatically retracted. A mild electric current then drives charged nanovesicles carrying insulin through the holes. The circuit is powered and controlled via a smartphone, which can alter the intensity of the current to determine the dosage of insulin delivered. The team showed that the device effectively delivered insulin to a diabetic rat model with no obvious harmful effects. It thus offers a powerful tool for efficient, controllable, and convenient delivery of macromolecular drugs.