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Ear Skin (ear + skin)
Selected AbstractsChanges in the levels of glutathione after cellular and cutaneous damage induced by squalene monohydroperoxideJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2001Katsuyoshi Chiba Abstract Squalene monohydroperoxide (Sq-OOH), the initial product of ultraviolet-peroxidated squalene, was used to investigate the effect of peroxidative challenge upon the glutathione contents in rabbit ear skin and primary-cultured fibroblasts derived from rabbit ear skin. The cellular reduced glutathione (GSH) contents decreased during 30-minute incubations in vitro with Sq-OOH, and oxidized glutathione (GSSG) was formed concomitantly, indicating that Sq-OOH had a potential for GSH-depleting activity in vitro. When Sq-OOH was applied topically to the skin in vivo, only GSSG contents increased significantly within 30 minutes. Moreover, pretreatment with the GSH depletors, DL -buthionine sulfoximine (BSO) and diethyl maleate (DEM), could potentiate the cytotoxicity and comedogenicity induced by Sq-OOH. These findings suggest that the endogenous antioxidant, glutathione, is quite sensitive to Sq-OOH and may be an important material for protecting cells and/or tissues against the oxidative stress induced by Sq-OOH treatment. © 2001 John Wiley & Sons, Inc. J Biochem Mol Toxicol 15:150,158, 2001 [source] Sumatriptan succinate transdermal delivery systems for the treatment of migraineJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2008C. Balaguer-Fernández Abstract We have successfully obtained sumatriptan transdermal systems with different polymer compositions: methyl cellulose (MC), polyvinyl pyrrolidone (PVP) and a polyvinyl pyrrolidone (PVP)-polyvinyl alcohol (PVA) mixture. The systems contained 1,2-propilenglycol (MC) or sorbitol as a plasticizer (PVP and PVP-PVA), methacrylate copolymer as an adhesive agent, and an occlusive liner. Azone® (5%, w/w) was incorporated into all the systems as a percutaneous enhancer. Transdermal systems are thin, transparent and non-adhesive when in a dry state. The permeation of sumatriptan succinate across pig ear skin was studied using the systems prepared. The formulation with MC polymer produced a statistically significant increment with respect to the PVP and PVP-PVA formulations (p,<,0.05). Azone® incorporation into the systems produced an increment in the sumatriptan flux values of all three transdermal systems with respect to those of the controls (p,<,0.05). In addition, the application of iontophoresis to the wet methyl cellulose-Azone® formulation produced a much higher increase of sumatriptan transdermal flux. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:2102,2109, 2008 [source] Porphyrin distribution after topical aminolevulinic acid in a novel porcine model of sebaceous skin,,LASERS IN SURGERY AND MEDICINE, Issue 2 2009Fernanda H. Sakamoto MD Abstract Background and Objective Aminolevulinic acid photodynamic therapy (ALA-PDT) depends on drug metabolism into porphyrins. Clinically, ALA-PDT has been used with a wide range of protocols for treating both epidermal and dermal targets, despite limited understanding of porphyrin biodistribution over time. We studied porphyrin accumulation after topical application of ALA in vivo, and also describe the porcine ear as a new animal model to study adnexal glands. Study Design/Materials and Methods The microanatomy of anterior ear skin of swine was measured. Topical 20% ALA in water/ethanol was applied under occlusion. Biopsies taken after 5, 10, 15, and then every 15 minutes for a total of 3 hours were examined by fluorescence microscopy of frozen sections to assess accumulation and distribution of porphyrins. Results Porphyrin fluorescence of digital photomicrograph images was not visually apparent until 30,45 minutes after application, although quantitative pixel analysis showed a statistically significant increase in epidermal fluorescence only 15 minutes after ALA application. From 30 to 120 minutes, epidermis, hair follicles (HF), and sebaceous glands (SG) became progressively more fluorescent. Eccrine gland fluorescence began to be detected after 30 minutes; SG showed fluorescence starting at 45,75 minutes. Fluorescence in all sites reached maximum intensity from 75 to 180 minutes of incubation. There was a trend for HF and SG to express stronger fluorescence compared with epidermis and eccrine glands. Conclusion Anterior pig ear skin is microanatomically similar to human sebaceous skin. The time-dependent accumulation of porphyrins in pilosebaceous units and eccrine glands in this model suggests other routes of uptake of topical ALA in addition to the trans-epidermal route. Apparently, time interval between ALA application and light exposure could be optimized for different uses of ALA-PDT. Lasers Surg. Med. 41:154,160, 2009. © 2009 Wiley-Liss, Inc. [source] Gene therapy for psoriasis in the K14-VEGF transgenic mouse model by topical transdermal delivery of interleukin-4 using ultradeformable cationic liposomeTHE JOURNAL OF GENE MEDICINE, Issue 6 2010Jiong Li Abstract Background Topical transdermal gene delivery to the skin shows great potential for painless, non-invasive administration of vaccines and therapeutic agents. Interleukin (IL)-4 strategies have shown a good antipsoriatic effect in clinic trials. To date, no information has been acquired on the effectiveness of gene therapy for psoriasis in the K14-VEGF transgenic mouse model by topical transdermal penetration of murine IL-4 (mIL-4) using ultradeformable cationic liposome (UCL). Methods In the present study, we synthesized an UCL and determined a suitable formula for transdermally delivering plasmid DNA to mouse skin. We then tested the antipsoriatic efficacy in the K14-VEGF transgenic mouse model by transdermal delivery of mIL-4 using UCL. Results We found that plasmid DNA was transdermally delivered to vicinal sites of epidermis and hair follicles using this optimized formula. Plasmid DNA expression was detected in ear skin. Twenty-four hours after topical application, plasmid DNA was not detected in blood serum and liver, which may decrease the risk of insertion of promoter from plasmid to genomic DNA. Mice treated with UCL/mIL-4 displayed a mild psoriasis phenotype. Histological analysis of pathological score using the Baker scoring system revealed an antipsoriatic effect. Immunohistochemical analysis revealed that hyperplastic and inflamed vessels were suppressed. Conclusions These observations provide evidence of antipsoriatic efficacy by topical transdermal delivery of mIL-4. Therefore, topical transdermal gene transfer is attractive and offers future potential for application in human patients with other dermatogic diseases. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||