Primo Fernando L, Bentley Maria V L B, Tedesco Antonio C
Departamento de Química, Laboratório de Fotobiologia e Fotomedicína, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901, Ribeirão Preto-SP, Brasil.
J Nanosci Nanotechnol. 2008 Jan;8(1):340-7.
In this work we evaluated the photophysical and in vitro properties of Foscan, a second-generation photosensitizer drug (PS) widely used in systemic clinical protocols for cancer therapy based on Photodynamic Therapy (PDT). We employed biodegradable nanoemulsions (NE) as a colloidal vehicle of the oil/water (o/w) type focusing in topical administration of Foscan and other photosensitizer drugs. This formulation was obtained and stabilized by the methodology described by Tabosa do Egito et al., based on the mixture of two phases: an aqueous solution and an organic medium consisting of nonionic surfactants and oil. The photodynamic potential of the drug incorporated into the NE was studied by steady-state and time-resolved spectroscopic techniques. We also analyzed the in vitro biological behavior carried out in mimetic biological environment protocols based on the animal model. After topical application in a skin animal model, we evaluated the Foscan/NE diffusion flux into the skin layers (stratum corneum and epidermis + dermis) by classical procedures using Franz Diffusion cells. Our results showed that the photophysical properties of PS were maintained after its incorporation into the NE when compared with homogeneous organic medium. The in vitro assays enabled the determination of an adequate profile for the interaction of this system in the different skin layers, with an ideal time lag of 6 h after topical administration in the skin model. The Foscan diffusion flux (J) was increased when this PS was incorporated into the NE, if compared with its flux in physiological medium. These parameters demonstrated that the NE can be potentially applied as a drug delivery system (DDS) for Foscan in both in vitro and in vivo assays, as well as in future clinical applications involving topical skin cancer PDT.
在本研究中，我们评估了Foscan的光物理性质和体外性质。Foscan是一种第二代光敏剂药物（PS），广泛应用于基于光动力疗法（PDT）的癌症治疗全身临床方案中。我们采用可生物降解的纳米乳剂（NE）作为油/水（o/w）型胶体载体，重点研究Foscan和其他光敏剂药物的局部给药。这种制剂是根据Tabosa do Egito等人描述的方法获得并稳定的，该方法基于两个相的混合：水溶液和由非离子表面活性剂和油组成的有机介质。通过稳态和时间分辨光谱技术研究了掺入NE中的药物的光动力潜力。我们还分析了基于动物模型在模拟生物环境方案中进行的体外生物学行为。在皮肤动物模型中局部应用后，我们使用Franz扩散池通过经典程序评估了Foscan/NE向皮肤层（角质层和表皮+真皮）的扩散通量。我们的结果表明，与均匀有机介质相比，PS掺入NE后其光物理性质得以保持。体外试验能够确定该系统在不同皮肤层中的相互作用的适当概况，在皮肤模型中局部给药后理想的时间滞后为6小时。与在生理介质中的通量相比，当该PS掺入NE中时，Foscan的扩散通量（J）增加。这些参数表明，NE在体外和体内试验中都有可能作为Foscan的药物递送系统（DDS）应用，以及在涉及局部皮肤癌PDT的未来临床应用中。
