“To date, none of the available inks has been optimised in terms of both printability and cell suspending ability,” according to ACES Associate Researcher Cameron Ferris.
Our new bio-ink is printable and cell-friendly, preventing cell settling and allowing controlled deposition of cells.”
The 2D structures being printed with the bio-ink enables exquisite control over cell distribution and this already presents exciting opportunities to improve drug screening and toxicology testing processes. Building on this, 3D bio-printing, with which patient-specific tissue replacements could be fabricated, is within the grasp of researchers.
“The development of chemistries that enable fabrication protocols not only takes us closer to practical devices but gives us experimental protocols that allows previously unexplored areas of fundamental science to be explored,” ACES Director Professor Gordon Wallace said.
ABSTRACT – Drop-on-demand bioprinting allows the controlled placement of living cells, and will benefit research in the fields of tissue engineering, drug screening and toxicology. We show that a bio-ink based on a novel microgel suspension in a surfactant-containing tissue culture medium can be used to reproducibly print several different cell types, from two different commercially available drop-on-demand printing systems, over long printing periods. The bio-ink maintains a stable cell suspension, preventing the settling and aggregation of cells that usually impedes cell printing, whilst meeting the stringent fluid property requirements needed to enable printing even from many-nozzle commercial inkjet print heads. This innovation in printing technology may pave the way for the biofabrication of multi-cellular structures and functional tissue.
The team printed cells in specific patterns onto collagen hydrogel, a soft and wet substrate that acts as a cushion for the cells as well as preventing dehydration.
‘In getting going practically with this or any other cell printing process, someone has to work out how to load the cells into cartridges and keep them alive until they are printed,’ says Paul Calvert, an expert in regenerative biomaterials from the University of Massachusetts, Dartmouth, US. ‘During printing, they need to be fed (by the medium) and given oxygen (not sure how that will work) and then be printed without settling down to block the nozzles. This work addresses the last problem. They show that the cells don’t die and go on to differentiate normally. This part has been shown before, but before this, people had to keep shaking the cartridge to keep the cells suspended.’
Inkjet printing of living cells is an important step towards in het Panhuis’s team’s goal of developing techniques for an all-printing approach to materials and devices for bionics and tissue engineering applications.