Image reversal for direct electron beam patterning of protein coated surfaces

Electron beam lithography (EBL) is used to create surfaces with protein patterns, which are characterized by immunofluorescence and atomic force microscopies. Both negative and positive image processes are realized by electron beam irradiation of proteins absorbed on a silicon surface, where image reversal is achieved by selectively binding a second species of protein to the electron beam exposed areas on the first protein layer. Biofunctionality at the cellular level was established by culturing cortical cells on patterned lines of fibronectin adsorbed on a bovine serum albumin background for 7 days in culture.     

A set of highly water-soluble tetraethyleneglycol-substituted Zn(II) phthalocyanines: synthesis, photochemical and photophysical properties, interaction with plasma proteins and in vitro phototoxicity

Three Zn(II) phthalocyanines substituted by hydroxyl-terminated tetraethylene glycol chains have been synthesized. In order to evaluate the potential of these highly water-soluble phthalocyanines as type II-photosensitisers for photodynamic therapy, their structure-activity relationship was assessed by determining relevant photophysical and photochemical properties, such as their aggregation behaviour in aqueous buffers, their fluorescence properties and their efficiency with regard to the generation of singlet oxygen. In addition, evidence for a negligible interaction with plasma proteins in undiluted human plasma was obtained using a recently developed bioanalytical method and compared with the fluorescence quenching approach. These results combined with in vitro data regarding the phototoxicity of these phthalocyanines against HT-29 cancer cells provide evidence for the relevance of the non-peripherally substituted derivative for further in vivo investigations.