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Posted: Jul 09, 2012
Effective material modification: Three-dimensional control of molecular click reactions
(Nanowerk News) The 2012 Lanxess Talent Award in the amount of EUR 4000 in the category of “Advances in Polymer Materials” goes to KIT polymer chemist Thomas Paulöhrl. With this new award Lanxess, a speciality chemicals group, honors young scientists for excellent work in the early phase of their academic career. For his Ph. D. thesis, Paulöhrl generated various surface structures and three-dimensional frameworks by means of light-induced click strategies. In this way, material can be modified efficiently and with nanometer precision.
Laser-induced modification of 3D surfaces for a more detailed understanding of the differentiation behavior of stem cells.
a) 3D polymer framework is functionalized at exactly defined locations with the help of laser light. (Schematic representation). (Image: Benjamin Richter)
In recent years, the interest in click reactions for effective material modification has increased significantly. Specifically assembled polymer surface patterns have a number of applications, for instance in tissue cultivation, cell biology, and medicine.
The concept of click chemistry goes back to the American chemist Barry Sharpless, who was the first to define this term in 2001. Complex molecular structures are first produced as partial rather than complete structures. During the subsequent reaction, these structures “click” together rapidly, similar to a peg game. Meanwhile, many of these molecular components have been described where clicking is spatially and temporally uncontrolled. However, non-controlled clicking is not sufficient for the manufacture of surface structures and three-dimensional frameworks.
In his Ph. D. thesis under the supervision of Professor Christopher Barner-Kowollik, Paulöhrl develops various chemical strategies for the production of three-dimensional surfaces by means of highly efficient spatially and temporally controlled click reactions. His trick: An exactly defined micrometer-scaled polymer basic framework to which biomolecules, activated by a second laser, click in a spatially predetermined manner.
Reconstruction of a 3D fluorescence microscopy. Defined locations (in red) are functionalized. (Image: Benjamin Richter)
The basic framework is the result of the interdisciplinary cooperation at the DFG Center for Functional Nanostructures (CFN). Paulöhrl used the 3D laser lithography method developed by Professor Martin Wegener and worked together with Ph. D. student Benjamin Richter from the group of Professor Martin Bastmeyer. This group has already explored the potential of this novel type of cell framework.
As a result, the molecules are fixed and their spatial position is influenced. Paulöhrl used photo-activable biomolecules, where the spatially resolved attachment process is triggered via light. As a result, nanometer-scaled material structures of biomarkers are produced. These biomarker frameworks are used among others for studying stem cell differentiation.