Sometimes I look at my printer and just shake my head at the thought that one day it might produce living cells if the researchers at University of Wollongong (New South Wales, Australia) have their way. From the Nov. 16, 2012 news item on phys.org,
Researchers have been aware for some time of the potential for using commercially available inkjet printer heads to print living human cells into 3D structures, but design of the actual ink capable of carrying cells through the printer has been a challenge.
The ARC Centre of Excellence for Electromaterials Science at UOW has led a team of scientists including Cameron Ferris, Dr Kerry Gilmore, Dr Stephen Beirne, Dr Donald McCallum, Professor Gordon Wallace and Associate Professor Marc in het Panhuis to develop a new bio-ink that improves the viability of living cells and allows better control of cell positioning through the printing process.
“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 Nov. 15, 2012 University of Wollogong news release, which originated the news item, provides some detail about what makes this new bio-ink exciting,
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 abstract for the researchers’ paper in Biomaterials helped me to build my understanding of this innovation,
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.
You can access the paper (free access) but you must be registered (it’s free) with RSC (Royal Society of Chemistry) Publishing. Here’s a link and the citation,
Cameron J. Ferris , Kerry J. Gilmore , Stephen Beirne , Donald McCallum , Gordon G. Wallace and Marc in het Panhuis
Biomater. Sci., 2013, Advance Article
Received 09 Aug 2012, Accepted 11 Oct 2012
First published on the web 05 Nov 2012
Even more helpful than the abstract and assuming you’re not ready to read the paper is Jennifer Newton’s Nov. 7, 2012 article for the RSC’s Chemistry World,
‘The first bio-inks used in drop-on-demand cell printing were simple salt solutions,’ says Marc in het Panhuis, who was part of the research team at the University of Wollongong. ‘The cells in these inks settled and aggregated quickly, which impeded printing. Cell viability can also be compromised if the salt concentration is too high.’
Other bio-inks include low viscosity biopolymer solutions, which are known to slow cell settling. The team’s bio-ink consists of a biopolymer – gellan gum – and two surfactants in a standard tissue culture medium. The surfactants – Novec FC4430 and Poloxamer 188 – reduce surface tension, allowing optimal inkjet printing, and protect the cells from fluid-mechanical damage.
The cells do not settle and aggregate because the biopolymer creates a structured network of micro-gel particles that keep the cells suspended in the gel. However, the bio-ink remains printable as the network is not rigid and is easily broken down during printing. ‘Our bio-ink allowed us to print multiple cell types over long printing periods without changing print heads or replenishing ink solutions,’ says in het Panhuis.
There are more details in Newton’s article and the image that accompanies it is quite striking.