Transdermal siRNA delivery by pH-switchable micelles with targeting effect suppress skin melanoma progression.

Melanoma is an aggressive disease with rapid progression and fast relapse, representing one of the formidable challenges in clinic. Current systemic therapies for melanoma exhibit limited anticancer potential due to the lack of specificity and limited efficacy. Herein, we design a cationic polymer (SCP-HA-PAE) by conjugating skin/cell penetrating peptide (SCP) and hyaluronic acid (HA) to the amphipathic polymer (poly β-amino esters, PAE), then fabricate the nanocarriers (SHP) composed by SCP-HA-PAE for delivering siRNA to skin melanoma by transdermal application. SHP not only manifests the excellent ability in penetrating through skin stratum corneum (SC), targeting melanoma and being sensitive to pH, but also expresses the advantages in compacting the vector/siRNAs nanocomplexes and stimulating their endosome escape inside cells, which ensure the enhanced siRNA delivery efficiency. SHP/siRNA induce the strong efficacy in retarding the progression and relapse of skin melanoma through the enhanced apoptosis effect both in vitro & in vivo. This study provides a proof-of-concept design of pH-switchable cationic micelles as transdermal gene delivery nanoplatforms with targeting effect for melanoma therapy, which may be adapted widely in the treatment of various superficial tumors and skin genetic diseases.