Topical administration of anti-cancer drugs along with
photodynamically
active molecules is a non-invasive approach, which stands to be a
promising modality for treating aggressive cutaneous melanomas with
the added advantage of high patient compliance. However, the efficiency
of delivering drugs topically is limited by several factors, such
as penetration of the drug across skin layers at the tumor site and
limited light penetrability. In this study, curcumin, an active anti-cancer
agent, and chlorin e6, a photoactivable molecule, were encapsulated
into lipidic nanoparticles that produced reactive oxygen species
(ROS) when activated at 665 nm by near-infrared (NIR) light. The optimized
lipidic nanoparticle containing curcumin and chlorin e6 exhibited
a particle size of less than 100 nm. The entrapment efficiency for
both molecules was found to be 81%. The therapeutic efficacy of the
developed formulation was tested on B16F10 and A431 cell lines via
cytotoxicity evaluation, combination index, cellular uptake, nuclear
staining, DNA fragmentation, ROS generation, apoptosis, and cell cycle
assays under NIR irradiation (665 nm). Co-delivering curcumin and
chlorin e6 exhibited higher cellular uptake, better cancer growth
inhibition, and pronounced apoptotic events compared to the formulation
having the free drug alone. The study results depicted that topical
application of this ROS-generating dual-drug-loaded lipidic nanoparticles
incorporated in SEPINEO gel achieved better permeation (80 ±
2.45%) across the skin, and exhibited the improved skin retention
and a synergistic effect as well. The present work introduces photo-triggered
ROS-generating dual-drug-based lipidic nanoparticles, which are simple
and efficient to develop and exhibit synergistic therapeutic effects
against cutaneous melanoma.