Dados do Trabalho

Título

Evaluation of Nanoemulsion for local transdermal therapy of Fenretinide as Chemoprevention Strategy

Introdução

Despite the high worldwide incidence, there are few pharmacological strategies for breast cancer prevention, and the existing ones have several adverse effects and low acceptance. To contribute to the development of new chemoprevention strategies, we propose a nanoemulsion (NE) for topical delivery of the retinoid fenretinide to the breast skin tissue. The NE incorporates the monoterpene limonene, with a dual role as a penetration and a cytotoxic enhancer.

Objetivo

The aim of our project was to assess the influence of limonene on the irritation potential of the nanoemulsion, fenretinide cutaneous delivery, cytotoxicity and migration of breast cancer cells.

Métodos

The nanoemulsion was produced using probe sonication under an ice bath and characterized for size by dynamic light scattering (ZetaSizer NanoZS). The irritation assay was performed with the HET-CAM experimental model, assessing hemorrhage, lysis, and coagulation. Skin penetration was assessed in Franz cells at 3, 6, and 12 hours. The quantification of fenretinide in tissues was performed using reverse-phase UV-HPLC. The cytotoxicity of the nanoemulsion was evaluated using MCF-7 and MDA-MB-231 breast cancer cells in monolayers. Cell viability was investigated using the MTT assay to determine the IC50 of the nanoemulsion; the treatments used was NE with 2.5% limonene (NE-L 2,5%), NE without limonene (NE), and control (DMSO solution + fenretinide, 4HPR) fro 48 and 72h. The effect of the nanoemulsion treatment for 24 h on the migration of breast cancer cell lines was assessed using a transwell inserts.

Resultados

The nanoemulsions displayed droplest in the range of 155 – 82.8 nm depending on the concentration of limonene. In skin penetration two factors influenced the distribution of fenretinide in the tissue: time and limonene concentration. In a 12-hour period, the NE L 2.5% significantly improved the penetration of fenretinide by 3.5-fold compared to the NE with 1%. Presence of limonene in the nanoemulsion (NE L 2.5%) reduced the IC50 in both cell lines in the both time periods studied. For MCF-7 cells, a reduction of 1.6 to 4-fold in 48 and 72 hours, respectively, was observed in comparison with NE without limonene. For MDA-MB-231: NE L 2.5% decreased IC50 values by 2 to 3-fold in the same time periods. The presence of limonene in the nanoemulsion did not influence cell migration: migration reduction (2-8-9.6-fold for MDA-MB231 and MCF-7 cells, respectively) was very similar after treatment with fenretinide-loaded NE with or without limonene.

Conclusões

The presence of limonene in the nanoemulsion enhanced the skin penetration of fenretinide and decreased the IC50 of the drug in two breast cancer cell lines employed in this study. Although the effect in cell migration was not different in systems with or without limonene, drug incorporation in the NE reduced cell migration compared to its solution. These results support the advantage of fenretinide incorporation in nanoemulsions for enhancement of skin penetration, cytotoxicity and reduction of migration.

Palavras-chave

Breast cancer, chemoprevention, nanoemulsion, fenretinide, local transdermal therapy.

Financiador do resumo

CAPES – Brazilian Federal Agency for Support and Evaluation of Graduate Education within the Ministry of Education of Brazil (finance code 001) and Fundação de Amparo à Pesquisa de São Paulo (FAPESP) grants 2021/06755-0, 2018/13877-1 e 2019/08582-5.