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 ß-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.

Construction of a biomimetic chemokine reservoir stimulates rapid in situ wound repair and regeneration.

Skin is the first protection of human body. It is always challenged by a range of external factors, resulting in the wounds of skin. Hydrogel, as a dressing with multiple advantages, causes increasing interests or the applications in wound treatment. However, the function and importance of micro-environment of wound region are frequently neglected. In this study, we successfully developed a chemokine loaded biomimetic hydrogel as a functional reservoir to stimulate the rapid in situ recruitment of BMSCs for fast wound repair and regeneration. The biomimetic hydrogel was fabricated by using the Polyvinyl alcohol (PVA) combined with chitosan (CS) as the hybrid materials. The fabricated hydrogel possesses many features such as the porous structure, high swelling rate and moisture retention property. More importantly, the incorporated chemokine could be released with a sustained manner from the hydrogel and recruited the bone marrow mesenchymal stem cells (BMSCs) significantly both in vitro & in vivo. Moreover, the hydrogel was demonstrated to be highly biocompatible to the skin tissue without any side effect or irritation observed. Topical delivery of chemokine by the biomimetic PVA/CS hybrid material based hydrogel is demonstrated as a promising carrier to accelerate wound repair and regeneration without inducing scar formation and any other negative complications. The PVA/CS/SDF-1 hydrogel was shown a novel therapeutic system for wound therapy.