Precise docking sites for cells

Dec 11, 2013
The biologically active surfaces are colored red and green in the fluorescence microscopy of the novel "Petri dish." Credit: KIT/B. Richter

The Petri dish is a classical biological laboratory device, but it is no ideal living environment for many types of cells. Studies lose validity, as cell behavior on a flat plastic surface differs from that in branched lung tissue, for example. Researchers of Karlsruhe Institute of Technology have now presented a method to make three-dimensional structures attractive or repellent for certain types of cells.

"Now, we can rapidly and precisely design the ideal Petri dish for single ," Barner-Kowollik explains. Barner-Kowollik's and Martin Bastmeyer's team of chemists and biologists at KIT developed a new photochemical surface coding method. It allows for the precise modification of three-dimensional microscaffolds. "Customized structuring of adhesion points for cells allows for studying the behavior of in a close-to-reality environment," Bastmeyer says.

The Petri dish resembles a miniaturized ropes course. Its size is one fiftieth of a millimeter at the maximum. Isolated cells can be hung up between traverses and observed without any disturbing impacts. By an appropriate coating of traverses and poles, the cells are kept at the desired place and, if necessary, stimulated to grow. "In this way, we can study the motion and force of individual cells," Bastmeyer points out.

To construct and coat the Petri dish with nanometer resolution, the cell researchers and polymer chemists use a direct laser writing method. Originally, this method was developed by the team of Martin Wegener from KIT for use in nanooptics. The three-dimensional scaffold forms at the points of intersection of two laser beams in a photoresist. At these points, the resist is hardened. For coating the scaffold, the team of Barner-Kowollik and Martin Bastmeyer uses various and a photoactive group. Coupling is activated at the points illuminated by the laser beam only. There, bioactive molecules bind chemically to the surface. The physico-chemical properties and parameters, such as the flexibility or three-dimensional arrangement of cell docking sites, can be adjusted with a high local resolution when using these modern photochemical methods.

A whole set of photochemical surface coding methods is now presented by six publications in the latest issues of the magazines Angewandte Chemie, Chemical Science, and Advanced Materials. Using this set of methods, chemical bonds can be produced efficiently and in a locally controlled manner without catalysts or increased temperatures being required. Depending on the application, it is possible to maximize coupling efficiency, to accelerate the photoreaction, to directly couple to unmodified biomarkers, to reduce chemical synthesis work, or to design areas where no cell adhesion can take place.

Explore further: Tiny oil droplets help measure mechanical forces produced by living cells that shape tissues and organs

More information: References:

[1] Pauloehrl, T.; Delaittre, G.; Winkler, M.; Welle, A.; Bruns, M.; Börner, H. G.; Greiner, A. M.; Bastmeyer, M.; Barner-Kowollik, C. Angew. Chem., Int. Ed. 2012, 51, 1071-1074.
[2] Pauloehrl, T.; Delaittre, G.; Bruns M.; Meißler M.; Börner, H. G.; Bastmeyer, M.; Barner-Kowollik, C. Angew. Chem., Int. Ed. 2012, 51, 9181-9184.
[3] Pauloehrl, T.; Welle, A; Bruns, M.; Linkert, K.; Börner, H. G.; Bastmeyer, M.; Delaittre, G.; Barner-Kowollik, C. Angew. Chem., Int. Ed. 2013, 52, 9714-9718.
[4] Pauloehrl, T.; Welle, A.; Oehlenschlaeger, K. K.; Barner-Kowollik, C. Chem. Sci. 2013, 4, 3503-3507.
[5] Richter, B.; Pauloehrl, T.; Kaschke, J.; Fichtner, D.; Fischer, J.; Greiner, A. M.; Wedlich, D.; Wegener, M.; Delaittre, G.; Barner-Kowollik, C.; Bastmeyer, M. Adv. Mater. 2013, DOI: 10.1002/adma.201302678.
[6] Rodriguez-Emmenegger, C.; Preuss, C. M.; Yameen, B.; Pop-Georgievski, O.; Bachmann, M.; Mueller, J. O.; Bruns, M.; Goldmann, A. S.; Bastmeyer, M.; Barner-Kowollik, C. Adv. Mat. 2013, DOI: 10.1002/adma.201302492

add to favorites email to friend print save as pdf

Related Stories

Nanostructures with living cells

Feb 05, 2013

Using laser technology, Aleksandr Ovsianikov from the Vienna University of Technology wants to create microstructures with embedded living cells.

The laser beam as a "3D painter"

Aug 27, 2012

(Phys.org)—There are many ways to create three dimensional objects on a micrometer scale. But how can the chemical properties of a material be tuned at micrometer  precision? Scientists at the Vienna University ...

Recommended for you

How calcium regulates mitochondrial carrier proteins

9 hours ago

Mitochondrial carriers are a family of proteins that play the key role of transporting a chemically diverse range of molecules across the inner mitochondrial membrane. Mitochondrial aspartate/glutamate carriers are part of ...

Precise measurements of microbial ecosystems

10 hours ago

The Luxembourg Centre for Systems Biomedicine (LCSB) has succeeded for the first time in describing the complex relationships within an ecosystem in unprecedented detail. For their work, carried out in collaboration ...

Students create microbe to weaken superbug

21 hours ago

A team of undergraduate students from the University of Waterloo have designed a synthetic organism that may one day help doctors treat MRSA, an antibiotic-resistant superbug.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.