Microneedle pretreatment and cationic nanoparticles for transdermal delivery of doxorubicin against melanoma

Transdermal drug delivery against skin cancer may be more effective than oral or injection delivery because patients may be more likely to complete the treatment and it may be less likely to trigger gastrointestinal side effects. Here we developed doxorubicin-loaded nanoparticles based on cationic polyethyleneimine-oleic acid for transdermal delivery , and we applied the nanoparticles to skin pre-treated with metal microneedles to facilitate their passage through the tough epithelial barrier. The cationic nanoparticles were extremely small, which probably also facilitated their transdermal passage. They accumulated in subcutaneous melanoma tumors in mice, slowing tumor growth and inducing apoptosis. These therapeutic effects were weaker but still significant when skin was not pretreated with microneedles. Our results suggest a promising new platform for transdermal treatment of skin cancer and potentially other skin diseases.