Outer membrane vesicles derived from E. coli as novel vehicles for transdermal and tumor targeting delivery.

Transdermal drug delivery is favored in clinical therapy because of its ability to overcome the shortcomings of the first pass elimination of the liver caused by traditional oral administration and the irreversibility of the injection. However, skin stratum corneum (SC) forms a big barrier that precludes most of the biomacromolecules. Herein, we propose the engineering of transformed Escherichia coli (E. coli) derived outer membrane vesicles, detoxified by lysozymes (named TEVs) as the carrier for transdermal drug delivery. TEVs were derived from transgenic E. coli and then modified by an integrin alpha(v)beta(3) (αvβ3) targeting peptide and co-loaded with indocyanine green (ICG) (P-TEVs-G). TEVs were shown to have excellence in penetrating through intact SC without any additional enhancement, followed by targeting of melanoma cells. TEVs are promising nanoplatforms for transdermal and tumor targeting drug delivery with high efficacy and biosafety, possessing great potential in the treatment of superficial tumors.