Company Claims High Speeds, Resolution in 3-D Printed Tissue

Prellis Biologics founders Melanie Matheu, right, and Noelle Mullin (Twitter.com)

21 June 2018. A company developing a three-dimensional printing technology to produce human tissue says it can produce tissue with higher resolution, including blood vessels, and higher speeds than before. Prellis Biologics Inc., a start-up enterprise in San Francisco, says its process brings the prospect closer of printing functional organ replacements, but it offers no independent verification of its claims, such as a peer-reviewed journal article or professional meeting paper.

The Prellis technology uses laser holograms that put down fine layers of extracellular matrix, secretions from cells that provide structural and biochemical support, already containing cells at near instantaneous speeds. Unlike most current tissue engineering methods, the Prellis process, according to the company, does not require previous cell seeding or additional culturing to produce tissue matrix. As a result, it achieves high printing speeds, which are critical for tissue production since densely packed cells will die in less than 30 minutes unless oxygen and nutrients can be supplied immediately with blood carried through capillaries.

The company says its process also lends itself to cell encapsulation, down to the level of single cells. Prellis says it can produce encapsulated single cells in less than 5 milliseconds, and produce many cells simultaneously to increase production speeds. In addition, the company uses far-red lasers in its process that do not harm the cells during production of tissue.

Prellis says it achieves high resolution as well, producing capillaries as small as 5 to 10 microns in diameter; 1 micron equals 1 millionth of a meter. The company says an array of tiny blood vessels, known as microvasculature, from 105 to 250 microns in length, can be produced in less than 6 minutes. ” Our ultimate goal,” says Prellis founder and CEO Melanie Matheu in a company statement, “is to print the entire vascular system of a kidney in 12 hours or less.”

Printing replacement organs is a key market for Prellis Biologics.  According to the web site OrganDonor.gov, more than 114,000 people in the U.S. are on waiting lists for organ transplants, as of April 2018, with another person added to the list every 10 minutes. Despite more than 34,000 organ transplants being performed in 2017, an estimated 20 people die each day waiting for a transplant. The vast majority of the waiting list individuals are seeking a kidney, according to the company, which intends to start designing nephrons, functioning kidney components, in its next stage of development.

Prellis says another market is medical devices, such as stents to keep blood vessels open, and therapeutic patches. The technology can also produce organoids, small cell collections for drug testing, as well as recreated patient tumors to test proposed cancer therapies. Still another use of the cell encapsulation properties of the printers is insulin-producing beta cells and associated blood vessels.

The company is less than two years old, spun off from University of California in San Francisco, founded by Matheu and UC-San Francisco colleague Noelle Mullin. As noted by Science & Enterprise in September 2017, Prellis Biologics gained $1.8 million in seed financing at the time led by venture investor True Ventures in Palo Alto, California, with participation by Civilization Ventures, 415 Ventures, and other angel investors. The company incubated at at IndieBio, a start-up incubator for bioscience enterprises in San Francisco that provides initial funding of $250,000 plus 4 months of training and mentorship.

The following brief (14 seconds) video shows real-time printing of a cell encapsulation device to produce small human cells containing organoids. The structure’s the size is 200 microns in diameter and can contain up to 2000 cells.

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