Fujita Alessandra Keiko Lima, Rodrigues Phamilla Gracielli Sousa, Requena Michelle Barreto, Escobar André, da Rocha Rozana Wendler, Nardi Andrigo Barboza de, Kurachi Cristina, de Menezes Priscila Fernanda Campos, Bagnato Vanderlei S
São Carlos Institute of Physics, University of São Paulo, PO Box 13560-970, Sao Carlos, SP, Brazil.
São Carlos Institute of Physics, University of São Paulo, PO Box 13560-970, Sao Carlos, SP, Brazil.
Photodiagnosis Photodyn Ther. 2016 Sep;15:236-44. doi: 10.1016/j.pdpdt.2016.05.008. Epub 2016 Jun 7.
Photodynamic Therapy (PDT) using Aminolevulinic acid (ALA) and derivative molecules as topical medication and as a precursor of protoporphyrin (PPIX), is limited due to low permeation through skin or efficiency in porphyrin production. This behavior affects the production and homogeneity of PPIX distribution on superficial skin and in the deeper skin layers. Many authors propose alternatives to solve this such as, modification in the ALA and derivativemolecules, modifying the chemical properties of emulsion external phase or incorporating a delivery system to the emulsion. The goal of this study is to discuss what proportion of ALA and Methyl aminolevulinate (MAL) on mixtures increase the amount and uniformity of PPIX formation at superficial skin by fluorescence evaluations.
The study was conducted in vivo using a pig skin model. PPIX production was monitored using fluorescence spectroscopy and widefield fluorescence imaging on skin surface. 20% of ALA and MAL cream were done mixing the following proportions: ALA, M2 (80% ALA-20% MAL), M3 (60% ALA-40% MAL), M4 (50% ALA-MAL), M5 (40% ALA-60% MAL), M6 (20% ALA-80% MAL) and MAL.
Mixtures M3, M4, and M5 showed the most PPIX production on skin by widefield fluorescence imaging and fluorescence spectroscopy in 3h of incubation. These results suggest that 50% of ALA and MAL in the same mixture increase the PPIX production in amount, homogeneity and time production when compared to ALA and MAL. This has a positive impact on photodynamic damage optimizing the PDT treatment.
使用氨基乙酰丙酸（ALA）及其衍生物分子作为局部用药和原卟啉（PPIX）前体的光动力疗法（PDT），由于其透过皮肤的渗透率低或卟啉生成效率低而受到限制。这种情况会影响PPIX在浅表皮肤和深层皮肤层中的生成及分布均匀性。许多作者提出了替代方案来解决这一问题，例如对ALA及其衍生物分子进行修饰、改变乳液外相的化学性质或在乳液中加入递送系统。本研究的目的是通过荧光评估来探讨ALA和甲基氨基乙酰丙酸（MAL）混合物中何种比例能增加浅表皮肤处PPIX形成的量和均匀性。
本研究采用猪皮肤模型进行体内实验。使用荧光光谱法和皮肤表面的宽场荧光成像监测PPIX的生成。将20%的ALA和MAL乳膏按以下比例混合：ALA、M2（80%ALA - 20%MAL）、M3（60%ALA - 40%MAL）、M4（50%ALA - MAL）、M5（40%ALA - 60%MAL）、M6（20%ALA - 80%MAL）和MAL。
在孵育3小时后，通过宽场荧光成像和荧光光谱法观察到，混合物M3、M4和M5在皮肤上产生的PPIX最多。这些结果表明，与ALA和MAL相比，相同混合物中50%的ALA和MAL能增加PPIX生成的量、均匀性以及生成时间。这对优化PDT治疗的光动力损伤有积极影响。
