TY  - GEN
A1  - Wirth, Jonas
A1  - Neumann, Rainer
A1  - Antonietti, Markus
A1  - Saalfrank, Peter
T1  - Adsorption and photocatalytic splitting of water on graphitic carbon nitride
BT  - a combined first principles and semiempirical study
N2  - Graphitic carbon nitride, g-C₃N₄, is a promising organic photo-catalyst for a variety of redox reactions. In order to improve its efficiency in a systematic manner, however, a fundamental understanding of the microscopic interaction between catalyst, reactants and products is crucial. Here we present a systematic study of water adsorption on g-C₃N₄ by means of density functional theory and the density functional based tight-binding method as a prerequisite for understanding photocatalytic water splitting. We then analyze this prototypical redox reaction on the basis of a thermodynamic model providing an estimate of the overpotential for both water oxidation and H⁺ reduction. While the latter is found to occur readily upon irradiation with visible light, we derive a prohibitive overpotential of 1.56 eV for the water oxidation half reaction, comparing well with the experimental finding that in contrast to H₂ production O₂ evolution is only possible in the presence of oxidation cocatalysts.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 172 
KW  - augmented-wave method
KW  - hydrogen
KW  - initio molecular-dynamics
KW  - oxidation
KW  - photooxidation
KW  - reduction
KW  - simulations
KW  - tight-binding
KW  - transition
KW  - visible-light
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-74391
SP  - 15917
EP  - 15926
ER  - 
TY  - GEN
A1  - Radbruch, Moritz
A1  - Pischon, Hannah
A1  - Ostrowski, Anja
A1  - Volz, Pierre
A1  - Brodwolf, Robert
A1  - Neumann, Falko
A1  - Unbehauen, Michael
A1  - Kleuser, Burkhard
A1  - Haag, Rainer
A1  - Ma, Nan
A1  - Alexiev, Ulrike
A1  - Mundhenk, Lars
A1  - Gruber, Achim D.
T1  - Dendritic core-multishell nanocarriers in murine models of healthy and atopic skin
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - Dendritic hPG-amid-C18-mPEG core-multishell nanocarriers (CMS) represent a novel class of unimolecular micelles that hold great potential as drug transporters, e. g., to facilitate topical therapy in skin diseases. Atopic dermatitis is among the most common inflammatory skin disorders with complex barrier alterations which may affect the efficacy of topical treatment.

Here, we tested the penetration behavior and identified target structures of unloaded CMS after topical administration in healthy mice and in mice with oxazolone-induced atopic dermatitis. We further examined whole body distribution and possible systemic side effects after simulating high dosage dermal penetration by subcutaneous injection.

Following topical administration, CMS accumulated in the stratum corneum without penetration into deeper viable epidermal layers. The same was observed in atopic dermatitis mice, indicating that barrier alterations in atopic dermatitis had no influence on the penetration of CMS. Following subcutaneous injection, CMS were deposited in the regional lymph nodes as well as in liver, spleen, lung, and kidney. However, in vitro toxicity tests, clinical data, and morphometry-assisted histopathological analyses yielded no evidence of any toxic or otherwise adverse local or systemic effects of CMS, nor did they affect the severity or course of atopic dermatitis.

Taken together, CMS accumulate in the stratum corneum in both healthy and inflammatory skin and appear to be highly biocompatible in the mouse even under conditions of atopic dermatitis and thus could potentially serve to create a depot for anti-inflammatory drugs in the skin.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 724 
KW  - CMS
KW  - skin
KW  - topical treatment
KW  - dermal delivery
KW  - atopic dermatitis
KW  - oxazolone
KW  - fluorescence lifetime imaging microscopy
KW  - nanomaterials
KW  - multi-domain nanoparticles
KW  - penetration enhancement
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-430136
SN  - 1866-8372
IS  - 724
ER  -