A novel self-assembling poly(ethylene glycol) hydrogel system based on inclusion complexes between β-cyclodextrin (β-CD) and cholesterol is described. Hydrogels are formed after hydration of a mixture of star-shaped 8-arm poly(ethylene glycol) (PEG) end-modified with β-CD groups and the same star-shaped PEG end-modified with cholesterol moieties. Rheological analysis as well as 2D-NMR spectroscopy demonstrated that the obtained gels are due to formation of β-CD/cholesterol inclusion complexes. As also observed by rheology, the hydrogels are fully thermoreversible upon repetitive heating and cooling steps. Hydrogel properties were dependent on polymer concentration, the β-CD/cholesterol stoichiometry, and the molecular weight of the starshaped PEG. Because of their assumed biocompatibility and expected physiological clearance, hydrogels based on star-shaped PEG and β-CD/cholesterol inclusion complexes offer excellent opportunities as drug delivery matrices and for other pharmaceutical and biomedical applications.

To achieve highly effective glucocorticoid targeting for rheumatoid arthritis therapy, novel, polymerizable and hydrolytically cleavable dexamethasone (DEX) derivatives were covalently entrapped in core-crosslinked polymeric micelles. By varying the oxidation degree of the thioether in the drug linker, the release rate of DEX could be tightly controlled. Upon administration of the most rapidly releasing DEX-micelles, highly efficient disease treatment was achieved in two different animal models of inflammatory arthritis.

Polymerisierbare und hydrolytisch spaltbare Derivate von Dexamethason (DEX, roter Punkt) wurden kovalent in kernverknüpften Polymer‐Micellen bestehend aus einem temperaturempfindlichen Blockcopolymer (gelber und grauer Baustein) eingeschlossen. Die Freisetzungsrate konnte über den Oxidationsgrad des Thioethers im Linker des Wirkstoffderivats gesteuert werden. Mit den DEX‐Micellen wurde entzündliche rheumatische Arthritis in zwei Tiermodellen effizient behandelt.

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