Better bioprinting with stem cells

July 4, 2011

Schematic of the EB formation process using bioprinting approach. Droplets of cell-medium suspension were bioprinted onto the lid of a Petri dish. (Credit: Biomicrofluidics)

Researchers at Harvard Medical School’s Bio-Acoustic Mems in Medicine Laboratory have developed a new automated bioprinting approach using stem cell embroids (aggregates of cells derived from embryonic stem cells).

Ever since an ordinary office inkjet printer had its ink cartridges swapped out for a cargo of cells about 10 years ago and sprayed out cell-packed droplets to create living tissue, scientists and engineers have dreamed of using a specialized bio-inkjet printer to grow new body parts for organ transplants or tissues for making regenerative medicine repairs to ailing bodies.

Both these new therapies begin with a carefully printed mass of embryonic stem cells. And now there’s progress on getting that initial mass of stem cells printed.

By extending his pioneering acoustical work that applied sound waves to generate droplets from fluids, Dr. Utkan Demirci and his team at Harvard Medical School’s (Brigham and Women’s Hospital) Bio-Acoustic Mems in Medicine Laboratory report encouraging preliminary results at an early and crucial point in a stem cell’s career known as embroid body formation.

They found that getting the embroid body formed correctly and without mechanical trauma was key to preserving the stem cells’ ability to develop into any desired tissue. The new automated bioprinting approach appears to do this better than manual pipetting in the “hang-drop” method traditionally used, the researchers said.

The researchers applied sound waves to generate droplets from fluids, achieving:

  • Enhanced uniformity of size and ability to control droplet size.
  • A scalable system that can print one cell or tens of thousands per droplet
  • Faster droplet formation — 160 droplets/seconds, versus 10 minutes for the hang-drop method.

Utkan Demirci, et al., Embryonic stem cell bioprinting for uniform and controlled size embryoid body formation, Biomicrofluidics, 2011; 5 (2): 022207 [DOI: 10.1063/1.3580752]