12th International Conference of Pharmaceutical Sciences

INTRODUCTION: Topical photodynamic therapy (PDT) is based on the administration of a photosensitizing drug and its selective retention in malignant tissue and its subsequent activation by light at specific wavelengths, causing cell death by the production of free radicals and/or reactive oxygen species [1, 2]. PDT has been applied to almost every type of superficial nonmelanoma skin cancer and numerous benign skin disorders [3-4]. Chloro-aluminium phthalocyanine (ClAlPc) is a lipophilic photosensitizers widely used in preclinical studies of PDT for the treatment of skin cancer [5]. Besides ClAlPc has excellent photochemical and photodynamic activity, this is insoluble in water, which limits its bioavailability and its administration in a physiological environment. In this scenario, several strategies have been proposed to improve the skin accumulation of photosensitizers, including the use of microemulsions, micelles, lipid-based nanoparticles, and polymer-based nanoparticles [5-10]. In this study, we described the preparation and characterization of hexagonal liquid crystalline nanodispersion (LCN) as a controlled drug delivery system for ClAlPc and tested their phototoxicity effect in A375 cells in vitro to investigate their efficacy in PDT for melanoma treatment.
MATERIALS AND METHODS: ClAlPc-loaded LCN was characterized according to their particle size, distribution and zeta potential, morphological aspects by atomic force microscopy, stability and phototoxic action in melanoma cell line (A375).
RESULTS: The mean of particle size were 198.56 (±1.0) and 179.7 (±2.0) for LCN in absence or ClAlPc presence, respectively. Negative zeta potential was approximately 40 and ClAlPc-loaded LCN maintained their physical stability from particle size and distribution over 15 days. In addition, ClAlPc-loaded LCN also presented biocompatibility in the dark for normal keratinocytes cell (HaCat) from 4 to 1300ng/mL and potent antitumor effect in PDT using 1J/cm2 for melanoma cell (A375) with nuclear cell damage at 300ng/mL.
CONCLUSION: This study demonstrated that ClAlPc-loaded LCN is a potent and promising photosensitizer drug in the photodynamic therapy.