MANAGEMENT DECISION MAKING IN MARKETING

Miniaturized microreactors enable photochemistry with laser irradiation in flow mode to convert azidobiphenyl into carbazole with high efficiency

Photochemistry with laser radiation in condensed phase using miniaturized photoreactors

Miniaturized microreactors enable photochemistry with laser irradiation in flow mode to convert azidobiphenyl into carbazole with high efficiency

Strukturierung und Modifizierung von Polymeren mit UV-Laserstrahlung für life science Anwendungen

The objective of this work was the development of new processing technologies with UV-laser radiation for high performance and biocompatible polymers in life science applications. The laser treated surfaces were characterized by a variety surface sensitive of methods. In these polymers different surface topologies were generated by ablation in order to study their wetting properties by measurement of water contact angles. With this protocol it was possible to generate a Lotus-effect on hydrophobic polymers like PDMS and an "anti"Lotus-Effect in more hydrophilic polymers like PEEK. No negative influence on the biocompatibility of polymer surfaces caused by laser treatment has been detected. Guided cell growth was stimulated along geometrically defined groves generated by laser ablation. Furthermore cells proliferate well through laser drilled holes. On PDMS the parameters for laser drilling of small geometrically defined holes were optimized and the holes were characterized. A special procedure based on the use of a protective coating was developed to avoid the build-up of debris around small structures. As an application of this methodology a laser drilled retina implant is described. The chemical changes on polymer surfaces caused by laser treatment in air have been examined on selected polymers. New functionalities generated by photo oxidation were identified by derivatization with fluorescent dyes. The functionalized micro structures were detected by florescence microscopy. Reactive compounds like azides were immobilized out of a solution surrounding the polymer onto its surface with high spatial resolution by use of laser radiation. This procedure for polymer surface modification might stimulate further research into the immobilization of bioactive molecules e.g. for applications in biochips

Strukturierung und Modifizierung von Polymeren mit UV-Laserstrahlung für life science Anwendungen

The objective of this work was the development of new processing technologies with UV-laser radiation for high performance and biocompatible polymers in life science applications. The laser treated surfaces were characterized by a variety surface sensitive of methods. In these polymers different surface topologies were generated by ablation in order to study their wetting properties by measurement of water contact angles. With this protocol it was possible to generate a Lotus-effect on hydrophobic polymers like PDMS and an "anti"Lotus-Effect in more hydrophilic polymers like PEEK. No negative influence on the biocompatibility of polymer surfaces caused by laser treatment has been detected. Guided cell growth was stimulated along geometrically defined groves generated by laser ablation. Furthermore cells proliferate well through laser drilled holes. On PDMS the parameters for laser drilling of small geometrically defined holes were optimized and the holes were characterized. A special procedure based on the use of a protective coating was developed to avoid the build-up of debris around small structures. As an application of this methodology a laser drilled retina implant is described. The chemical changes on polymer surfaces caused by laser treatment in air have been examined on selected polymers. New functionalities generated by photo oxidation were identified by derivatization with fluorescent dyes. The functionalized micro structures were detected by florescence microscopy. Reactive compounds like azides were immobilized out of a solution surrounding the polymer onto its surface with high spatial resolution by use of laser radiation. This procedure for polymer surface modification might stimulate further research into the immobilization of bioactive molecules e.g. for applications in biochips

Laser structuring and modification of surfaces for medical and micro chemical components

In the production of micro devices the surface properties become more and more important for chemistry and biotechnology with respect to surface wetting, fluidic characteristic and biochemical properties for micro reactors, biochemical miniaturized devices for DNA- and proteome analysis and medical micro implants. In all that cases specific surface properties has to be set to conduct fluids and cells. Plasma treatment and co-polymerisation are well used for large area applications but have limited access to small geometries. For this applications newly designed laser technologies for surface processing have been developed to manipulate the fluidic surface properties even for channel sizes < 100 µm. The technology is based on excimer-laser treatment of polymer surfaces using laser wavelength < 200 nm with different fluences and cumulated energies. Depending on the processing parameters and used polymers either hydrophobe of hydrophil surfaces can be produced. In ideal cases the wetting angles can be increased from 90 deg C to almost 140 deg C so that the surface acts with the so called lotus effect. This effect has been used as guiding aids for cells on medical micro-implants leading the cells to grow along desired directions. Typical results for cell growing experiments are shown for different polymers

A triazene-based new photolabile linker in solid phase chemistry

An extension of the T2 linker methodology by showing its applicability as a photocleavable linker is reported. Photocleavage was carried out with 355 nm UV laser irradiation (3Omega Nd-YAG) in methanol/diethyl ether and is suitable for protected amino acid derivatives, as well as simple small organic molecules including resin-bound biotin. The linker is stable under a wide range of conditions with the exception of strongly acidic medi