Capturing living cells in micro pyramids

Scientists of the research institutes MESA+ and MIRA of the University of Twente in The Netherlands present this new technology and first applications in the journal Small.

Most cell studies take place in 2-D: this is not a natural situation, because cells organize themselves in differently in the human body. If you give the cells room to move in three dimensions, the set-up is closer to what we find in nature. This is possible in the 'open pyramids' fabricated in the NanoLab of the MESA+ Institute for Nanotechnology of the University of Twente.

Tiny corner remains filled

If you join a number of flat silicon surfaces to form a sharp corner, it is possible to deposit another material on them. After having removed the the bulk of the material, however, a small amount of material remains in the corner. This tiny tip can be used for an Atomic Force Microscope, or, in this case, for forming a micro pyramid.

Catching cells

In cooperation with UT's MIRA Institute for Biomedical Technology and Technical Medicine, the nanoscientists have explored the possibilities of applying the pyramids as 'cages' for cells. First experiments with polystyrene balls worked out well. The next experiments involved capturing chondrocytes, cells forming cartilage. Moved by capillary fluid flow, these cells automatically 'fall' into the pyramid through a hole at the bottom. Soon after they settle in their 3-D cage, cells begin to interact with cells in adjacent pyramids. Changes in the phenotype of the cell can now be studied in a better way than in the usual 2-D situation. It is therefore a promising tool to be used in tissue regeneration research.

The Dutch scientists expect to develop extensions to this technology: the edges of the pyramid can be made hollow and function as fluid channels. Between the pyramids, it is also possible to create nanofluidic channels, which could be used to feed the cells.