A $2,000 bioprinter engineered at the University of Alabama represents a low-cost option for printing scaffold-The crucial components of the bioprinter are (i) the layer-by-layer print head and (ii) the needle array. Source: University of AlabamaThe crucial components of the bioprinter are (i) the layer-by-layer print head and (ii) the needle array. Source: University of Alabamafree, functional tissues. The system constructs tissue by use of pre-grown spheroids of human induced-pluripotent stem cells that contain 200,000 cells per spheroid.

Unlike the Kenzan bioprinting method developed in Japan, which synthesizes tissue one spheroid at a time, the new system manipulates multiple spheroids simultaneously and maneuvers them onto a matrix of pins. A prototype constructed with commercially available components and equipped with a 4-by-4 matrix of 16 pins handles 16 spheroids at once with a cycle speed of 45 seconds, demonstrating a marked increase in scaffold-free bioprinting speed.

Glass beads were used to measure the spheroid retrieval efficiency for the vacuum pump-print head, and alginate beads were then used to test the machine’s ability to correctly print onto the needle array. Pregrown spheroids of human induced-pluripotent stem cells were also used to confirm the ability of the bioprinter to transfer a single layer of cellular spheroids onto the needles.

The bioprinter described in Micromachines efficiently picks up and transfer spheroids to the printing stage in a single, complete layer, decreasing the printing time of large tissue constructs. The researchers expect the device to lend itself to the low-cost and simple synthesis of custom tissues.

To contact the author of this article, email shimmelstein@globalspec.com