This method could facilitate the formation of micropatterned co-cultures and contribute to in vitro investigations of multicellular interactions and to tissue engineering.
The adhesion and growth of cells on solid carriers is necessary for many applications using laboratory-cultured tissues, diagnosis chips and biosensors.
However, the coating of a carrier contains a material that has ethylene glycol units as free end groups, which makes it almost impossible for cells to stick.
The German research team found that treatment with an oxidising substance such as bromine turns the antistick nature of the surface into one attractive to cells.
This effect can also be applied to small and specific areas of the carrier if the bromine is in contact with these defined areas.
To achieve this, the help of microelectrodes and a solution that contains bromide ions is needed. The electrodes are positioned close to selected areas of the carrier and a short pulse is applied.
This converts the bromide ions into bromine, which acts only on a local area of the surface.
Gunther Wittstock, head of physical chemistry at the University of Oldenburg, told labtechnologist.com: "Until now it was possible to stick one type of cell by modifying the surface chemistry but it was very complicated."
He said the process was permanent and less flexible. "You would 'stamp' the cells permanently. It was similar to creating a mould. Now it's like using a pen: you can draw a pattern on the carrier and add to it indefinitely."
The new microelectrochemical method will make processes such as toxicity tests and communication between cell types easier as it will be possible to add different cell types on one surface.