Scientists8217; first step toward growing artifical human cells

Reporting the findings at a recent meeting of American Chemical Society ACS, Ohio University researcher Douglas Kniss said his team8217;s work laid the foundation for artificially growing cells that develop specialised characteristics, just as cells that make up organs naturally do in the body.

In tests using a bioreactor, the scientists coaxed human placental cells to form clusters and initiate the same kind of chemical changes which occur before body8217;s formative cells called stem cells differentiate to make organs.

A forest of microscopic polyester fibres anchor living cells in the bioreactor which allows cells to grow and reproduce as they do in the body. Liquid nutrients flow steadily through the bioreactor, mimicking blood.

The cells in the bioreactor cling to the polyester fibres the way human cells attach themselves to proteins in the body.

The researchers found that enlarging or shrinking gaps between the fibres in the bioreactor affects growth and development of the cells, says a release from the university.

The polyester, according to the researchers, acts like a solid at room temperature and like a liquid at higher temperature. At a specific temperature of around 71 degrees celsius, it exhibits characteristics of both solid and liquid at the molecular level.

If the polyester is compressed during this critical junction, it retains its shape as well as its special molecular properties, the researchers say.

By precisely controlling pressure, temperature and compression time, they could adjust the size of the gaps. The new technique provides a way to modify the fibre structure which is like a scaffold supporting a sculpture, says Kniss.

When the gap between the fibres is small enough for the cells to easily bridge the gap, they reproduce quickly, which reflects the initial stage of rapid cell production when organs begin to form in the body. When the gap is too large for the cells to cross, they grow on top of each other forming clusters, as they do in the body before they differentiate.

When placental cells were grown in two bioreactors with average gap sizes of 30 micrometres and 40 micrometres, cells in the former reproduced very quickly and spread throughout the bioreactor.

Those in the latter, however, formed clusters in the open spaces and initiated chemical functions similar to those seen in the body before cells differentiate. The cells slowed down reproduction, consumed more glucose, produced more lactic acid and began producing estrogen, a key hormone produced by placental cells.