Transdermal therapy for skin and metabolic diseases

Skin is the readily accessible window for a wide range of theranostic purposes. Transdermal drug delivery across skin barrier-stratum corneum could be an effective method for treating numerous diseases. In this thesis, transdermal therapies based on polymeric microneedle (MN) patch and injectable thermo-responsive hydrogel were investigated for their therapeutic performance on skin and metabolic diseases. Firstly, a new transdermal strategy using an antimicrobial MN patch is invented for treating deep cutaneous fungal infection, which is difficult to be treated by conventional topical formulations or oral intake of antifungal agents due to low drug bioavailability to the infection site, lack of sustained therapeutic effect, and development of drug resistance. This MN patch is not only able to overcome the skin barrier, but also possesses antimicrobial property immune to drug resistance and provides sustained drug release because MN itself is made of biocompatible and biodegradable chitosan–polyethylenimine copolymer. Using a fungal infection mouse model, it is demonstrated that this MN patch incorporated with antifungal agent amphotericin B offers outstanding treatment effectiveness, which is credited to the high bioavailability of therapeutics and sustained synergistic actions from the antifungal polymer and drug.Doctor of Philosoph