G. E. M. Tovar

Water treatment by molecularly imprinted polymer nanoparticles

Molecular recognition capabilities are evoked at artificial materials by the NANOCYTES ® -technology of the Fraunhofer IGB, Stuttgart, Germany. The biomimetic nanoparticles described here possess such molecularly recognizing properties. For this purpose they carry molecularly defined binding sites at their surface. In this particular case molecularly imprinted nanospheres (nanoMIPs) were developed for the specific adsorption of micropollutants from hospital waste water. Active pharmaceutical substances and their metabolites which were not decomposed by waste water plants were chosen as model compounds. One of this model compounds is Pentoxifylline. The nanoMIPs are prepared by a miniemulsion polymerization technique, where the monomer, the template, the cross-linker, and the initiator do react in the droplet cavities of the miniemulsion. The reaction to obtain nanoMIP particles is complex, but nevertheless it runs in a single reaction chamber and in a single step chemical process. For synthesis of the polymer system p(methacrylicacid- co -ethylenglycoldimethacrylate), p(meth-acrylicacid- co -methylmethacrylate- co -ethylenglycoldimethacrylate) and p(4-vinylpyridin- co -ethylenglycoldimethacrylate) are used. The technique of miniemulsion polymerization results in particles with a typical size distribution of 50 nm to 500 nm. Additionally, an introduced magnetic core will allow the final separation of the nanoMIPs and more important of the recognized pollutants from (waste) water. We demonstrate that magnetite can be incorporated into the polymer system, and that the template Pentoxifylline does not affect the polymerization process.

In vitro study of mouse fibroblast tumor cells with TNF coated and Alexa488 marked silica nanoparticles with an endoscopic device for real time cancer visualization

Tumor resection done by minimally invasive procedure owns the challenge of a fast and reliable differentiation between healthy and tumorous tissue. We aim at investigating and developing a method for an intraoperative visualization of tumor cells with functionalized nanoparticles. The goal is to use this technique for the intraoperative use. Our so-called biohybrid systems consist of nanoparticles that are produced by Stober synthesis and coupled with bio active proteins. Such biomimetic nanostructures are capable of imitating the effects of membrane-bound cytokines, which bind to tumor cells for labeling them. A flexible and modular test environment has been developed to evaluate the spraying properties of the particles and to study tissue probes. It enables a fast investigation of different particle configurations and spraying parameters like pressure, spray volume, nozzle geometry, etc.