Circle of Life

Scientists from Rockefeller University, US, have coaxed human embryonic stem cells to organise it into parts of the human body as they would naturally by confining it in a radius with the help of micropatterns. The advance would help biologists in creating ‘pure population’ of specific cells for use in medical treatments.

In the natural process, seven days after conception, a process starts in the clump of cells to eventually transform into a new human being. Then starts the process of specialisation wherein the process takes on the characteristics to form skin, brain, muscle or any of the roughly 200 cell types that exist in a human body. In the uterus, the stem cells receive chemical signals from surrounding tissues to begin forming layers, a process known as gastrulation. Cells in the centre form ectoderm (brain and skin of embryo), while those migrating outside turn into mesoderm and endoderm (muscle and blood and other major organs). Researchers studied what exactly happens during this chemical process and surmised that the answer to replicate the process is not chemical but geometrical. Previous experiments were unsuccessful as researchers used chemical signals instead of geometry.

Scientists thus confined human embryonic stem cells to tiny circular patterns on glass plates that were chemically treated to form micropatterns. These micropatterns prevented cell colonies from expanding outside a specific radius. Researchers then chemically signalled these cells to begin gastrulation and found that the colonies that were geometrically confined proceeded to form endoderm, mesoderm and ectoderm just as in natural conditions. It was also found that the cells which were not confined in the radius did not form any distinct layers.