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Gewählte Doctoral Thesis:

Doctoral Thesis - Abteilung für Chemie nachwachsender Rohstoffe, BOKU-Universität für Bodenkultur, pp 228. UB BOKU obvsg FullText

Data Source: ZID Abstracts
The present thesis is concerned with a novel two-step modification of different cellulosic starting materials for wound coverages with the objective of improved wound healing through light-triggered destruction of bacteria and odorous compounds that occur e.g. in chronic wounds. The active agent for this approach is singlet oxygen (1O2), a highly reactive type of ambient-air molecular oxygen. Cellulose, and especially bacterial cellulose as a renewable and sustainable starting material, was pre-modified by silanization using (3-azidopropyl)triethoxysilane, followed by click chemical modification. The obtained materials were comprehensively characterized regarding their physicochemical properties. The above mentioned azido-functionalization was optimized for potential industrial application using different never-dried cellulose starting materials in aqueous suspension at room temperature. In a second step the pre-modified celluloses were reacted with several alkynated xanthene-derivatives by so-called Cu(I) catalyzed Huisgen azide-alkyne cycloaddition yielding photo-active cellulosic materials. The xanthene dye reagent molecules were directly characterized regarding their singlet oxygen production properties by laser flash photolysis as well as by an indirect approach using a selective singlet oxygen quencher. Cellulose materials being equipped with singlet oxygen producing molecules were then subject to photo-antimicrobial testing, in which control runs were carried out in the absence of light. Photo-antibacterial activity against gram-positive bacteria Staphylococcus aureus and Bacillus subtilis was observed in the case of Rose Bengal-derived photosensitizer materials. Generally, the presented protocol of modification of native, never-dried celluloses by silanization represents a very versatile route towards functionalized materials, starting from this renewable and sustainable raw material.

Betreuer: Rosenau Thomas
1. Berater: Potthast Antje
2. Berater: Böhmdorfer Stefan

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