Inkjet prints human cells

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Inkjet prints human cells

March 23/30, 2005

By Smalley, Technology Research News

One of the key tools used in research aimed at growing replacement

organs and tissues is the everyday inkjet printer.

The printers have been used to make scaffolds for growing tissue and

to spray cells in nutrient-rich liquids onto surfaces. Key challenges

are putting the right cells in the right places and ensuring that the

cells survive the rough ride.

Researchers from the University of Manchester in England have devised

a method that delivers human cells unharmed to chosen locations within

polymer scaffolds. " The scaffold is... built from a material designed

to degrade in the body and be absorbed over a timescale of months, "

said Derby, a professor of materials science at the University

of Manchester. " While this occurs, the cells multiply and generate

tissue to replace the scaffold. "

The researchers are working with reconstructive surgeons to put the

method to the test by growing tissues to reimplant in the donor, said

Derby. " Applications include replacement for bones removed during

cancer surgery [and] working with burn victims to regenerate skin, " he

said. " Because we use the patient's own cells we remove rejection

problems with the implants. "

The method could also be used to build experimental environments for

monitoring the responses of cells to external stimuli, and for

building cell-based biosensors, said Derby.

Previous research proved that cow cells can survive inkjet printing.

The University of Manchester researchers used human fibroblast and

osteoblast cells, which are the cells that form muscle and bone

tissue. The cells are forced at high pressure through a 30-micron wide

nozzle. A micron is one thousandth of a millimeter. " In an inkjet

printer, the drops are generated at extreme shear rates and at

accelerations greater than 100g, " said Derby. Shear is opposite forces

in parallel planes acting on an object. One g is the force of gravity.

The researchers showed that human cells printed into wells containing

nutrients could multiply, spread out and form attachments to the

surface during a six day incubation period. The researchers used

printer driving voltages of 30 and 60 in order to ensure that the

velocity was low enough to avoid harming the cells.

The researchers also used an inkjet printer to form a tissue scaffold

and to seed the scaffold with cells, said Derby. Ordinarily, tissue

scaffolds are immersed in a liquid containing cells. With this setup,

however the cells only penetrate a few millimeters, he said. " Our

technique allows the seeding of scaffold interiors as they are built, "

he said.

In addition, the immersion approach can only seed scaffolds with

homogenous mixtures of cells, said Derby. The researchers' method

provides precise control of cell position, which allows the

researchers to deposit different types of cells in different

locations, he said.

The researchers are working to allow the method to produce thicker

structures, said Derby. " We are currently limited to one or two layers

of cells and scaffold, " he said.

Moving beyond this requires better temperature control of the

substrates and a method for providing nutrient supply during printing,

said Derby.

The cell printing technique could be used practically in five to ten

years, said Derby.

Derby's research colleagues were Saunders and Gough of

the University of Manchester in England, and Nuno Reis of the

University of Manchester and the Institute of Technology (IST) in

Portugal. They presented an previous version of the method at the

Materials Research Society Fall 2003 meeting held in Boston December 1

through 5. The research was funded by the UK Engineering and Physical

Science Research Council (ESPRC) in the UK.

Timeline: 5-10 years

Funding: Government

TRN Categories: Biotechnology; Applied Technology

Story Type: News

Related Elements: Technical paper, " Ink-Jet Printing of Human Cells, "

Materials Research Society Fall 2003 meeting, Boston, December 1-5,

2003

http://www.trnmag.com/Stories/2005/032305/Inkjet_p

rints_human_cells_032305.html

[Guest guest]

, this is totally amazing! Thank you for posting this! ~ G