Effective Skin Cancer Treatment by Topical Co-delivery of Curcumin and STAT3 siRNA Using Cationic Liposomes

The aim of the present study was to evaluate the effectiveness of iontophoretic co-delivery of curcumin and anti-STAT3 siRNA using cationic liposomes against skin cancer. Curcumin was encapsulated in DOTAP-based cationic liposomes and then complexed with STAT3 siRNA. This nanocomplex was characterized for the average particle size, zeta-potential, and encapsulation efficiency. The cell viability studies in B16F10 mouse melanoma cells have shown that the co-delivery of curcumin and STAT3 siRNA significantly (p < 0.05) inhibited the cancer cell growth compared with either liposomal curcumin or STAT3 siRNA alone. The curcumin-loaded liposomes were able to penetrate up to a depth of 160 μm inside the skin after iontophoretic (0.47 mA/cm²) application. The in vivo efficacy studies were performed in the mouse model of melanoma skin cancer. Co-administration of the curcumin and STAT3 siRNA using liposomes significantly (p < 0.05) inhibited the tumor progression as measured by tumor volume and tumor weight compared with either liposomal curcumin or STAT3 siRNA alone. Furthermore, the iontophoretic administration of curcumin-loaded liposome-siRNA complex showed similar effectiveness in inhibiting tumor progression and STAT3 protein suppression compared with intratumoral administration. Taken together, cationic liposomes can be utilized for topical iontophoretic co-delivery of small molecule and siRNA for effective treatment of skin diseases.