| 1. |
- Lademann, Jürgen, et al.
(author)
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Drug delivery with topically applied nanoparticles : science fiction or reality
- 2013
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In: Skin Pharmacology and Physiology. - : S. Karger. - 1660-5527 .- 1660-5535. ; 26:4-6, s. 227-233
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Journal article (peer-reviewed)abstract
- The efficacy of topically applied drugs is determined by their action mechanism and their potential capacity of passing the skin barrier. Nanoparticles are assumed to be efficient carrier systems for drug delivery through the skin barrier. For flexible nanoparticles like liposomes, this effect has been well demonstrated. The penetration properties of solid nanoparticles are currently under intensive investigation. The crucial advantage of nanoparticles over non-particulate substances is their capability to penetrate deeply into the hair follicles where they can be stored for several days. There is no evidence, yet, that solid particles ≥40 nm are capable of passing through the healthy skin barrier. Therefore and in spite of the long-standing research efforts in this field, commercially available solid nanoparticle-based products for drug delivery through the healthy skin are still missing. Nevertheless, the prospects for the clinical use of nanoparticles in drug delivery are tremendous. They can be designed as transport systems delivering drugs efficiently into the hair follicles in the vicinity of specific target structures. Once deposited at these structures, specific signals might trigger the release of the drugs and exert their effects on the target cells. In this article, examples of such triggered drug release are presented.
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| 2. |
- Mak, Wing Cheung, 1977-, et al.
(author)
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Drug delivery into the skin by degradable particles
- 2011
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In: European journal of pharmaceutics and biopharmaceutics. - : Elsevier. - 0939-6411 .- 1873-3441. ; 79:1, s. 23-27
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Journal article (peer-reviewed)abstract
- Recently, it was demonstrated that particles could be utilized as carrier systems for drugs into the hair follicles. In the present study, a two-component drug delivery system is presented consisting of degradable particles loaded with fluorescein isothiocyanate and a separate protease formulation for degradation. The particles were applied alone, 30 min previous to the protease application and simultaneously with the protease onto porcine skin. Subsequently, biopsies were removed, and the penetration depths of the particles were analyzed using laser scanning microscopy.The obtained results demonstrate that the particles alone achieved a penetration depth of around 900 μm. Similar results were obtained for the successive application of particles and protease, whereas a release of the fluorescent dye was only observed in the upper 250 μm corresponding to the penetration depth of the protease. In the case of the simultaneous application, the particles were partly dissolved before application, leading to a reduced particle size and diminished penetration depth.The results revealed that degradable particles are a promising tool for drug delivery into the skin.
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| 3. |
- Wing Cheung, Mak, et al.
(author)
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Triggering of drug relase of particles in hair follicles
- 2012
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In: Journal of Controlled Release. - : Elsevier. - 0168-3659 .- 1873-4995. ; 160, s. 509-514
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Journal article (peer-reviewed)abstract
- Particulate drug delivery via hair follicles represents a promising concept, although requirements are high. This process must be realized at the desired depth and at the appropriate time, due to the fact that the particles themselves are not able to overcome the follicular skin barrier.In the present study, a novel triggering concept for the release of a model drug from the delivering particles is presented based on the application of two different particle types of the same size, where one particle type is the drug carrier, and the second one is loaded with a protease. The latter particle type is supposed to interact with the drug-carrying particles to trigger the drug release. A mixture of both particles was applied onto porcine skin samples, followed by follicular analysis. As a control, the particles were applied unaided without protease, whereas one skin area remained untreated. The investigations revealed that the protease was able to release the model drug from the delivering particles in significant depths within the hair follicle (866 ± 62 nm). Additionally, an uptake of the model drug in the sebaceous gland was observed after release providing a promising novel approach for the development of treatment strategies for different skin diseases.
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