New pectin-based hydrogel containing imiquimod-loaded polymeric nanocapsules for melanoma treatment.

We developed a pectin-based hydrogel containing nanocapsules as a new strategy for melanoma treatment. Our first objective was to evaluate the nanoencapsulation effect of imiquimod on melanoma. Imiquimod-loaded polymeric nanocapsules (NCimiq) showed significant time-dependent decrease in cell viability after treatment at 3 µmol L-1 (79% viable cells in 24 h and 55% in 72 h), which was not observed in cells treated with the solution of the drug (IMIQ) (99% viable cells in 24 h and 91% in 72 h). The second objective was to develop the hydrogel containing the drug-loaded nanocapsules (PEC-NCimiq). In vitro release study showed that 63% of imiquimod was released from the pectin-based hydrogel containing the drug (PEC-imiq) after 2 h, while 60% of the drug was released from PEC-NCimiq after 8 h. In the permeation study, 2.5 µg of imiquimod permeated the skin within 8 h after the initial contact of PEC-NCimiq, whereas only 2.1 µg of drug permeated after 12 h of contact when PEC-imiq was assayed. Pectin-based hydrogels enabled the drug penetration in all skin layers, especially the dermis (PEC-NCimiq = 6.8 µg and PEC-imiq = 4.3 µg). In the adhesion study, PEC-NCimiq showed the highest adhesiveness (42% removed from the skin) in comparison to PEC-imiq (71% removed from the skin). In conclusion, the nanoencapsulation provided a higher cytotoxic effect of imiquimod in SK-MEL-28, and the incorporation of the drug-loaded nanocapsules in pectin-based hydrogel showed higher adhesiveness and deeper penetration of the drug into the skin. Graphical abstract.

Anti-HPV Nanoemulsified-Imiquimod: A New and Potent Formulation to Treat Cervical Cancer.

Cervical cancer is associated with the human papilloma virus (HPV) and nowadays is the fourth most frequent cancer among women. One of the treatments for this disease is based on the application of imiquimod. In this study, we postulated that the use of imiquimod in nanoemulsion results in a better antitumoral effect than the drug administered in its nonencapsulated form for the treatment of cervical cancer. Permeability studies using vaginal mucosa, as membrane, and in vitro studies involving cervical cancer cells (viability, clonogenic assay, and cell death analysis) were performed. We showed that low amount of encapsulated imiquimod permeated the vaginal mucosa. However, a higher percentage of cells died after the treatment with low amount (3.0 µmol L-1) of the formulation compared to the free drug. In addition, the innovative formulation presented a combinatory mechanism of cell death involving autophagy and apoptosis. Our results demonstrate that the imiquimod-loaded nanoemulsioncan be an alternative product for the treatment of cervical cancer validating the hypothesis.

Imiquimod-loaded nanocapsules improve cytotoxicity in cervical cancer cell line.

This paper proposes the development of imiquimod-loaded polymeric nanocapsules formulation for the treatment of cervical cancer. The mechanism of death involved in the reduction of the cell viability as well as the production of an inflammation marker (IL-6) after the treatment in cell line SiHa have been evaluated. The formulation has significantly decreased the viability of the cells in a time-dependent manner, after 24, 48 and 72 h. Additionally, results showed a cellular decrease of almost 80% of the cells after 72 h of treatment. The formulation induced death by apoptosis, necrosis, autophagy, and increased the percentage of SubG1subpopulation of SiHa cells after 72 h. After the same time-interval, the formulation significantly prevented the appearance of colonies, showing effectiveness against SiHa. Finally, the formulation stimulated SiHa cells to release IL-6. These findings open new possibilities for the development of aqueous nanosuspension containing imiquimod as a novel strategy for the treatment of cervical cancer.