In vivo evaluation of antitumoral and antiangiogenic effect of imiquimod-loaded polymeric nanoparticles.

The chemotherapeutic agent imiquimod (Imq) is used to treat skin cancers, the most common type of human cancer. However, the high incidence of local and systemic side effects associated with its use as well as its low skin permeation impair patient compliance and therapeutic effectiveness To overcome these limitations, nanostructured systems such as nanoparticles can be a promising alternative. Nanoparticles are submicron particles (size less than 1000 nm) with high surface area that facilitates the interaction and cellular uptake by biological membranes. Therefore, the aim of the present work is to evaluate antiangiogenic effect and antitumoral activity of imiquimod-loaded nanoparticles compared to market Imq formulation. Polymeric nanoparticles containing Imq were obtained by the technique of precipitation of preformed polymer. Antiangiogenic activity of the formulations was determined in chicken embryo chorioallantoic membrane (CAM) and its chemopreventive potential was evaluate during multistage DMBA and croton oil model of skin carcinogenesis in mice. Nanoparticles containing Imq presented antiangiogenic activity superior than negative control, placebo dispersion and market Imq (p < 0.05) in the CAM model and also significantly reduced the number and size of papillomas compared to all other groups. These results suggest, therefore, that the obtained delivery system can be an alternative to treat diseases related to vessels formation and also potentially increase cutaneous permeation and efficacy of poor soluble drugs normally used to treat cutaneous diseases.