A research team in Alberta has found a way to coat stainless steel with glass silica and carbohydrates so the metal (already in general use) can be more effective in implanted biomedical devices. From the April 27, 2011 news item on Nanowerk,
Implanted biomedical devices, such as cardiac stents, are implanted in over 2 million people every year, with the majority made from stainless steel. Stainless steel has many benefits – strength, generally stability, and the ability to maintain the required shape long after it has been implanted. But, it can also cause severe problems, including blood clotting if implanted in an artery, or an allergenic response due to release of metal ions such as nickel ions.
This particular initiative, devising a means to trick the body’s immune system into better acceptance of implants, is part of a larger project where the goal is,
… to allow cross-blood type organ transplants, meaning that blood types would not necessarily need to be matched between donor and recipient when an organ becomes available for transplantation.
In the meantime, the team has found a means that they hope will make the stainless steel implants easier for the immune system to accept,
… sophisticated carbohydrate (sugar) molecules needed to be attached to the stainless steel surface to bring about the necessary interaction with the body’s immune system. Its inherent stainless characteristic makes stainless steel a difficult material to augment with new functions, particularly with the controlled and close-to-perfect coverage needed for biomedical implants. The Edmonton-based team found that by first coating the surface of the stainless steel with a very thin layer (60 atoms deep) of glass silica using a technique available at the National Institute for Nanotechnology, called Atomic Layer Deposition (ALD), they could overcome the inherent non-reactivity of the stainless steel. The silica provide a well-defined “chemical handle” through which the carbohydrate molecules, prepared in the Alberta Ingenuity Centre for Carbohydrate Science, could be attached. Once the stainless steel had been controlled, the researchers demonstrated that the carbohydrate molecules covered the stainless steel in a highly controlled way, and in the correct orientation to interact with the immune system.
In trying to find out a little more about this project, I found a presentation* from 2008 (or earlier) made by Todd Lowary, Jillian Buriak, and Lori West, presumably for investment purposes, about another initiative associated with this project titled, Infant Heart Transplants and Nanotechnology. Here’s the hypothesis from slide 3 of the presentation,
Hypothesis: Exposing a newborn to ABO antigens attached to a nanoparticle or stent will induce tolerance during immune development and in turn allow transplants across the blood-group barrier.
Since a baby’s immune system isn’t fully developed at birth, exposing a child in need of a cardiac transplant to a suitably nanoparticle-coated stent would theoretically allow the child to develop tolerance for blood group types other than its own thereby allowing a cross-blood type organ transplant. Towards the end of the presentation (which isn’t dated), they have a timeline which includes filing for various patents and a proposed date of 2013 for human clinical trials.
*The presentation is on the Alberta Centre for Advanced Microsystems and Nanotechnology Products (ACAMP). According to their About page,
ACAMP (Alberta Centre for Advanced MNT Products) is a not for profit organization that provides specialized services to micro nano technology clients.
ACAMP’s services encompass key areas identified as critical for the commercialization of MNT products – Marketing & Business Development, Product Development, Packaging and Assembly, Test and Characterization.
That’s it for today.
ETA July 4, 2011: There’s a May 16, 2011 news item by Cameron Chai on Azonano about this team which offers additional information.