Creating nanoparticles that have the ability to “guide” others into specifically designed positions is a thing that would undoubtedly open doors to the creation of a new class of devices. These future gadgets would have the ability to arrange themselves in the correct patterns inside spaces such as our cells and to construct nano-computers able to perform complex actions without outside interference. But making the particles stick together without getting clumped up is very complicated.

Researchers at the Case Western Reserve University, the Duke University and the University of Massachusetts in Amherst think they may have found a way in which to make this a reality. They have created a specific class of nanoparticles that could be the answer to bioengineers' prayers one day. In their bid to create artificial organs, these experts oftentimes find themselves faced with a very serious problem – how to make blood vessels grow and nourish the cellular clumps that will make for the organs, and how to make the cells themselves stick together?

The team has managed to make us aware of the basic properties of magnetic fields, by creating a new class of molecules that is able to act in very much the same way sheep dogs do, as in seek out any lost sheep (in our case a human cell in a special solution), and then force it to return to the herd. In the case of living cells, the particles force the free-floating cells in the solution to bind with others, thus making it possible for scientists to create the basics of artificial organs without actually forcing the cells together with pressure.

“The cells have receptors on their surfaces that have an affinity for other cells. They become sticky and attach to each other. When endothelial cells get together in a linear fashion, as they did in our experiments, it may help them to organize into tiny tubules,” Case Western Reserve University Biomedical Engineering biomedical engineering graduate student Melissa Krebs, the first co-author of the new paper detailing the find, explains. The study will appear in the May issue of the American Chemical Society (ACS)'s journal Nano Letters.

“The other main benefit of our approach is that we are creating three-dimensional cell chains without any sophisticated techniques or equipment. Any type of tissue we'd ultimately want to engineer will have to be three-dimensional,” she adds.

“While still in the early stages, we have shown that we can form oriented cellular structures. The next step is to see if the spatial arrangement of these cells in three dimensions will promote vascular formation. A major current hurdle in tissue engineering is vascularization, and we hope that this technology may help to address the problem,” CWRU assistant professor of biomedical engineering and orthopedic surgery Eben Alsberg concludes. He is also the senior author of the Nano Letters paper.