Liquid Crystal Nanodispersions Enable the Cutaneous Delivery of Photosensitizer for Topical PDT: Fluorescence Microscopy Study of Skin Penetration

Author(s)

Garcia Praca, Fabiola Silva ^[1] ; Garcia Medina, Wanessa Silva ^[1] ; Petrilli, Raquel ^[1] ; Lopes Badra Bentley, Maria Vitoria ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040160 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: CURRENT NANOSCIENCE; v. 8, n. 4, p. 535-540, SEP 2012.
• Web of Science Citations: 17

Abstract

Topical photodynamic therapy (PDT) has been applied to almost all types of nonmelanoma skin cancer and numerous superficial benign skin disorders. Strategies to improve the accumulation of photosensitizer in the skin have been studied in recent years. Although the hydrophilic phthalocyanine zinc compound, zinc phthalocyanine tetrasulfonate (ZnPcSO4) has shown high photodynamic efficiency and reduced phototoxic side effects in the treatment of brain tumors and eye conditions, its use in topical skin treatment is currently limited by its poor skin penetration. In this study, nanodispersions of monoolein (MO)-based liquid crystalline phases were studied for their ability to increase ZnPcSO4 uptake by the skin. Lamellar, hexagonal and cubic crystalline phases were prepared and identified by polarizing light microscopy, and the nanodispersions were analyzed by dynamic light scattering. In vitro skin penetration studies were performed using a Franz's cell apparatus, and the skin uptake was evaluated in vivo in hairless mice. Aqueous dispersions of cubic and hexagonal phases showed particles of nanometer size, approximately 224 +/- 10 nm and 188 +/- 10 nm, respectively. In vitro skin retention experiments revealed higher fluorescence from the ZnPcSO4 in deeper skin layers when this photosensitizer was loaded in the hexagonal nanodispersion system when compared to both the cubic phase nanoparticles and the bulk crystalline phases (lamellar, cubic and hexagonal). The hexagonal nanodispersion showed a similar penetration behavior in animal tests. These results are important findings, suggesting the development of MO liquid crystal nanodispersions as potential delivery systems to enhance the efficacy of topical PDT. (AU)

• FAPESP's process: 08/08317-5 - Evaluation of phototoxic effects of ZnPcSO4 on the bioenergetic and mitochondrial function of cell culture: influence of delivery system based on nanoparticles of liquid crystal on the photosensitizer intracellular delivery
• Grantee: Wanessa Silva Garcia Medina
• Support Opportunities: Scholarships in Brazil - Post-Doctoral