Animal-free drug discovery prospect
Xaar, a company famous for pushing back the boundaries of inkjet technology, has embarked on a multi-million pound project that could place it firmly at the forefront of medical science and drug research for years to come.Xaar, a company famous for pushing back the boundaries of inkjet technology, has embarked on a multi-million pound project that could place it firmly at the forefront of medical science and drug research for years to come.
The Cambridge company is collaborating on a project with the University of Manchester to design and build a machine capable of ‘printing’ bone and skin grafts to the strictest of clinical conditions.
Xaar sees the £2m, three-year project as an important step on a road that could lead to the replacement of animal experimentation in the drug discovery process, personalised toxicity screening for cancer patients and even the inkjet printing of bespoke replacement organs using a patient’s own cells.
Xaar’s business development manager Robert Harvey stresses that even the earliest implementations of the technology are five or more years away, but sees it as one of the most important markets for his company going forward.
Even the nearest term applications of inkjet printing as a medical device are incredibly exciting, promising perfectly tailored skin grafts, for example, which minimise post-operative scarring. Xaar estimates that this market alone is worth hundreds of millions of pounds annually.
Xaar reports that it has already overcome the ‘pure engineering’ challenges inherent in the project and is aiming to have a fully operational system, capable of printing skin cells by the end of this year. Amazingly, it plans to be able to actually experimentally apply grown skin samples by the end of 2008.
Harvey told us: “It is relatively well documented that a number of different types of human tissue cells are able to survive being passed through the inkjet printing process.
“The aim of this project is to take that very elementary knowledge and develop a system capable of operating in real-world clinical conditions.”
The consortium, which also includes the University of Manchester and a number of SME’s, recently suffered “a minor setback” when one company providing the capability to validate the skin patches withdrew from the project.
Harvey is confident that another company will soon fill the void and would like to see one of the many suitable East of England companies getting in touch.
The key technical hurdles to have been negotiated thus far are issues of cross-contamination; the design of a system geared up to work in sterile conditions; and also proofing the system to the saline solutions commonly used.
Xaar is funding a post-doctoral post at the University of Manchester to investigate the survival rates of different types of cell having been ‘fired’ through the system, a critical barrier to full commercialisation. To have any hope of passing through the regulatory processes, results must be standardised and replicable.
With the state of the art in tissue engineering as it stands at the moment, keeping structures alive once they have been ‘processed’ remains a problem, with the effective replication of a blood supply system beyond the reach of current know-how.
This is why Xaar is concentrating on structures which do not require a dedicated blood supply network, that is bone and skin.
The rise in the use of specialist robots to perform intricate surgical procedures makes Xaar’s proposition even more compelling, according to Harvey: “We are looking some way into the future, but we see a situation where, in bone cancer surgery for example, the diseased section of bone is replaced with a new section, accurately manufactured by the machine from data gathered from a CAT-scan.
“This information not only enables us to produce a new section, but also to cut-away the diseased area to achieve a precisely matched cavity.
“The robotic surgeon is connected to an inkjet machine which can print a new section of bone, layer by layer, using the information from the CAT scan. The result is a new piece of bone that exactly matches the piece that was removed, reducing healing times and improving aesthetic results. “The same is also true of skin patches, which could be manufactured to precisely match the size and shape of the wound.”
The skin cells are fired into a biodegradeable, fibre ‘scaffold,’ together with nutrients and growth factors, to which they willingly bind. When the graft has implanted and fused with surrounding cells, the scaffold gradually ‘melts’ away.
One of the most exciting applications and not as far off as you may think, is the manufacture of artificial organs – although only of a size to fit on a microscope slide.
The technology could have massive implications in the drug development industry and also point of care healthcare.
“We hope to be able to print little colonies of liver or kidney cells that live on a microscope slide. We would then pump blood with a novel drug in it, through the structure to see what effect it has.
“This has profound potential in the early-stage drug development process. The kidney and the liver are typically good indicators of the toxicity of a particular treatment.”
The key to the inkjet manufacture of complex structures such as kidneys and livers may well be dependent on stem cell technology, Harvey believes.
Although he believes that the proximity of Cambridge’s growing stem cell cluster will be of great benefit going forward, Xaar’s own expertise is not yet sufficiently developed for any formal meeting to be productive.
He said: “Obviously there are still ethical issues to be resolved, but if we were able to inkjet growth factors, chemical signalling agents, nutrients and the stem cells themselves, DNA could orchestrate much of the building task.
“If, for example, The DNA decided there was a deficiency of bloodflow in the vicinity, they would take over and create a few more blood vessels.
“If the stem cells came from the patient themselves, then the organ would be in no danger of being rejected.”