Martin Braun

Ochrobactrum anthropi endophthalmitis after uncomplicated cataract surgery.

PURPOSE To treat a case of Ochrobactrum anthropi endophthalmitis after uneventful cataract surgery. METHODS A 66-year-old patient in good general health underwent uncomplicated cataract surgery in his right eye. Seven weeks later, pars plana vitrectomy with removal of the intraocular lens became necessary because of progressive low-grade endophthalmitis resistant to topical and systemic erythromycin, cephalosporins, aminoglycosides, and colistin. RESULTS Microbiologic examination of the vitreous biopsy, capsule, and anterior chamber fluid disclosed O. anthropi, a nonfermentative gram-negative bacillus sensitive to imipenem, amikacin, ciprofloxacin, and vancomycin. CONCLUSION Ochrobactrum anthropi and its natural resistance against many antibiotics should be considered in the treatment of low-grade endophthalmitis after uneventful cataract surgery.

Synthesis of a Biotinated Lipofullerene as a New Type of Transmembrane Anchor

As a prototype for a new class of lipid membrane components, the lipophilic fullerene derivative (so-called lipofullerene) 1 was synthesized and characterized. This mixed [1:5]-hexakisadduct consists of ten long alkyl chains within five didodecyl malonate addends and a linker malonate carrying a (+)-biotin unit as part of an amphiphilic spacer. The malonates are attached to the fullerene core in an octahedral addition pattern, which was achieved by two successive cyclopropanation sequences with the functional precursor malonate 8 and dodecyl malonate 10. The final step of the synthesis of 1 was the attachment of activated biotin 5 with the deprotected precursor 11. Binding experiments followed by reflectometric interference spectroscopy [RIfS] proved the capability of 1 to bind specifically the protein streptavidin (SA) through the biotin unit. The amphiphilic behavior of 1 was demonstrated by Langmuir Blodgett (LB) film investigations.

Fullerene derivatives in bilayer membranes: an overview

Abstract Since lipophilic fullerene derivatives, so-called lipofullerenes, are found to be unprecedentedly soluble in lipid membrane bilayers, a new concept to modify the physical and mechanical properties as well as the functionalization of membranes by aggregation with fullerenes is accessible. Several model compounds ( 1a/b, 2a/b/c/d, 3 ) are realized and their behaviour in membrane bilayers was extensively investigated [M. Hetzer, S. Bayerl, X. Camps, O. Vostrowsky, A. Hirsch, T.M. Bayerl, Adv Mater 9 (1997) 913]. We present a brief overview of recent results to introduce this outstanding and promising approach to entirely new supramolecular structures. Alteration of the lipofullerene, for example by polymerizable butadiyn units ( 2d, 4c–7c ) as well as hydrophilic moieties combined with biofunctional end groups as (+)-biotin ( 3–7 ) extends the possibilities to build tailor-made nanostructures with well- defined biocompatible functions.

A chiral dumbbell shaped bis(fullerene) oligoelectrolyte

The first icosacationic bis(fullerene) whose water solubility is provided by twenty peripheral ammonium groups has a rigid, almost cylindrical shape and was synthesized by connecting two fullerene cores with a chiral cyclo-bis(malonate), followed by the regioselective addition of ten amino-terminated malonates into the octahedral positions of the fullerene moieties and subsequent cleavage of the Boc-protecting groups.