Desenvolvimento de lipossomas e imunolipossomas de cloro alumínio ftalocianina contendo ácido oleico para potencial uso na Terapia Fotodinâmica em câncer

Abstract

Photodynamic therapy (PDT) is a promising cancer treatment modality, but its clinical success can be limited due to photosensitizer molecules, such as chloroaluminum phthalocyanine (AlClPc), being lipophilic and prone to aggregation in aqueous media, leading to a loss of efficacy. Consequently, the use of nanotechnologies, as well as chemical and/or physical absorption promoters, can decrease its toxicity and side effects. Squamous cell carcinoma (SCC) overexpresses the epidermal growth factor receptor (EGFR). Thus, the conjugation of the cetuximab antibody to liposomes containing AlClPc may favor cellular uptake. The use of physical methods capable of increasing skin penetration can also be applied. In breast cancer, the use of oleic acid incorporated into liposomes can be acted by regulating the neoplastic behavior of the cells. Thus, the present work aims to develop and physicochemically characterize liposomes and immunoliposomes containing oleic acid and AlClPc, to evaluate the use of photodynamic therapy in cutaneous SCC and breast carcinoma cells, and the use of physical methods for promoting skin penetration. To this end, a Quality by Design approach was employed, using a Box-Behnken design. Particle size, polydispersity index, and zeta potential were evaluated, and the encapsulation percentage was quantified by spectrofluorimetry. From the resulting formulation, composed of soy phosphatidylcholine (SPC), cholesterol (Col), oleic acid (AO), and DSPE-PEG (2000) in a ratio of 70:18:13.4:1.7, the conjugation of the cetuximab antibody was performed with a functionalization efficiency of 66.12%. In vitro studies were conducted on EGFR-positive cell lines (A431 and 4T1), resulting in better cytotoxicity for liposomes compared to the AlClPc solution. In in vitro skin penetration studies, a twice increase in AlClPc penetration was observed using microneedling in the viable epidermis. The mathematical modeling of the drug's diffusion process in the skin reinforces that the developed formulation exhibits retention behavior and slow diffusion between skin layers, which is ideal for topical application, with an R² = 0.94 and Dsc = 1.78x10-11 m²h-1. In conclusion, this work presents an innovative and multifaceted approach to improving PDT for cancer treatment. The liposomal system was successfully developed through factorial planning, as was the conjugation of the cetuximab antibody. The in vitro evaluation demonstrated the cytotoxic potential of photodynamic therapy, and the use of physical methods promoted greater skin penetration, showing its potential in the future of oncology.