Magnetic Cellular ‘Legos’ For Tissue Engineering

By incorporating magnetic nanoparticles in cells and developing a system using miniaturized magnets, researchers from 3 associated universities* in Paris (France) , have succeeded in creating cellular magneticLegos.” They were able to aggregate cells using only magnets and without an external supporting matrix, with the cells then forming a tissue that can be deformed at will. This approach, which is detailed in Nature Communications, could prove to be a powerful tool for biophysical studies, as well as the regenerative medicine of tomorrow.

Nanotechnology has quickly swept across the medical field by proposing sometimes unprecedented solutions at the furthest limits of current treatments, thereby becoming central to diagnosis and therapy, notably for the regeneration of tissue. A current challenge for regenerative medicine is to create a cohesive and organized cellular assembly without using an external supporting matrix. This is a particularly substantial challenge when it involves synthesizing thick and/or large-sized tissue, or when these tissues must be stimulated like their in vivo counterparts (such as cardiac tissue or cartilage) in order to improve their functionality.

The researchers met this challenge by using magnetism to act on the cells at a distance, in order to assemble, organize, and stimulate them. Cells, which are the building blocks of tissue, are thus magnetized in advance through the incorporation of magnetic nanoparticles, thus becoming true cellular magnetic “Legos” that can be moved and stacked using external magnets. In this new system acting as a magnetic tissue stretcher, the magnetized cells are trapped on a first micromagnet, before a second, mobile magnet traps the aggregate formed by the cells. The movement of the two magnets can stretch or compress the resulting tissue at will.

Researchers first used embryonic stem cells to test their system. They began by showing that the incorporation of nanoparticles had no impact on either the functioning of the stem cell or its capacity for differentiation. These functional magnetic stem cells were then tested in the stretcher, in which they remarkably differentiated toward cardiac cell precursors when stimulation imposed “magnetic beating” imitating the contraction of the heart. These results demonstrate the role that purely mechanical factors can play in cell differentiation.

This “all-in-one” approach, which makes it possible to build and manipulate tissue within the same system, could thus prove to be a powerful tool both for biophysical studies and tissue engineering.

* Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot), in collaboration with the Laboratoire Adaptation Biologique et Vieillissement (CNRS/UPMC) and the Centre de Recherche Cardiovasculaire de Paris (Inserm/Université Paris Descartes)


Building A Nanoscope Like a LEGO

The world’s first low cost Atomic Force Microscope (AFM) or Nanoscope has been developed in Beijing – China – by a group of PhD students from UCL – United Kingdom -, Tsinghua University and Peking University – using Lego.

In the first event of its kind, LEGO2NANO brought together students, experienced makers and scientists to take on the challenge of building a cheap and effective AFM, a device able to probe objects only a millionth of a millimetre in size – far smaller than anything an optical microscope can observe.
Lego game AFM 2

Low-cost scientific instrumentation is not just useful in high-schools, it can be a huge enabler for hospitals and clinics in developing countries, too” notes Gabriel Aeppli, director of the London Centre for Nanotechnology at UCL, a key contributor to the event, “That’s why novel initiatives like LEGO2NANO are so important.”
Low-cost scientific instruments, using cheap consumer hardware and open-source software, are becoming increasingly popular: for example, many researchers now collect data using apps on mobile phones.
Designing these state-of-the-art and low cost technologies has become an objective of industry, academia and now also the maker community, groups of talented amateurs around the globe who like to develop DIY solutions.
It’s impressive to see the UCL students working closely with their Chinese counterparts. The event was not only interdisciplinary, it also crossed the boundary between science and maker cultures”, remarked Prof. Xiao Guo, Pro-Provost (China) of UCL.