الفهرس 
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Abstract
Topical photodynamic therapy has been explored in the treatment of various cutaneous diseases. It is likely to allow a more precise dosage of both the delivered light intensity and the intralesional Photosensitizer (PS) concentration. Moreover, the onset of persistent cutaneous photosensitivity, which represents an undesired side effect of PDT with intravenously injected photosensitizers, is minimized. However, the major limitation of topical PDT is the poor penetration of photosensitizers through skin and the efficient penetration of the PS into skin layers is essential to achieve successful PDT results. Consequently various techniques have been developed in order to increase skin penetration of photosensitizers and overcome the barrier properties of the skin. The use of vesicles such as liposomes and transfersomes is the wide spread interest. Among the dyes used in photodynamic therapy Methylene Blue (MB) is widely known. It has interesting characteristics conferring to this molecule a great potential for application in PDT. Loading of MB into vesicular systems can play a pivotal role in improving its topical delivery by enhancing its dermal localization. In this work, different formulation of MB loaded liposomes and transfersomes were prepared and evaluated for physicochemical characteristics and formulated into hydrogels (0.05% MB). The topical photodynamic effect MB loaded vesicles through dorsal mice skin were studied and compared to free MB. Then, a single-blind clinical study was to evaluate the efficacy and safety of transfersomal Methylene Blue photodynamic therapy (TMB-PDT) compared to free methylene blue (FMB) for the treatment of recalcitrant common plantar warts (PW). Among formulations prepared, transfersomal formulation without cholesterol showed best physicochemical properties. Histological examination revealed that only transfersomal MB gel was able to exert photodamage and inflammatory response in deep layers of mice skin, while effect of liposomal and free MB gels was only confined to epidermis and superficial layers of mice skin. Clinical results showed that both FMB and TMB treated groups showed significantly higher percentage of completely healed lesions than placebo group, but TMB treated group showed higher percentage of completely healed lesion (86.67%) with lower mean number of sessions (2.2) required for complete healing compared to FMB treated group. Neither pain, nor recurrence which was the main problems of standard treatment modalities used for PW was observed. The study pointed out that transfersomal MB shows superior properties over liposomal MB as topical drug delivery system, and TMB-PDT is effective and safe therapeutic modality for the treatment of PW.