Tuning the Cell and Biological Tissue Environment through Magneto-Active Materials

Abstract

This review focuses on novel applications based on multifunctional materials to actuate biological processes. The first section of the work revisits the current knowledge on mechanically dependent biological processes across several scales from subcellular and cellular level to the cell-collective scale (continuum approaches). This analysis presents a wide variety of mechanically dependent biological processes on nervous system behaviour; bone development and healing; collective cell migration. In the second section, this review presents recent advances in smart materials suitable for use as cell substrates or scaffolds, with a special focus on magneto-active polymers (MAPs). Throughout the manuscript, both experimental and computational methodologies applied to the different treated topics are reviewed. Finally, the use of smart polymeric materials in bioengineering applications is discussed.

Curing spurious magneto‐mechanical coupling in soft non‐magnetic materials

“…where b is the magnetic b-field (magnetic flux), h is magnetic h-field (magnetic intensity). From (15) it is clear that b and h can be expressed in terms of potentials as b = curl a and h = −grad 𝜙, (16) with a being the (magnetic) vector potential and 𝜙 the auxiliary scalar magnetic potential. While not of real physical significance, 𝜙 is particularly convenient for computations.…”

“…application of magnetoactive materials as mechanically active substrate for biological experiments. 16 In the simulations, the beam is first exposed to gravity g = 9.81 m s −1 and in a second step to a combined loading through gravity and a uniform external magnetic field b ∞ = 1 T. The generic energy density function employed is given as…”

“…It depicts a bilayer beam consisting of a magnetic $$$ {\mathcal{B}}^{\mathrm{magn}} $$$ and a non‐magnetic layer $$$ {\mathcal{B}}^{\mathrm{nonm}} $$$ that is clamped at its vertical symmetry axis and surrounded by “empty” space $$$ {\mathcal{B}}^{\mathrm{a}} $$$. This setting is inspired by prior examples of MRE beams 71,76,77,107 and the prospective application of magnetoactive materials as mechanically active substrate for biological experiments 16 . In the simulations, the beam is first exposed to gravity $$$ g=9.81\kern0.3em \mathrm{m}\kern0.3em {\mathrm{s}}^{-1} $$$ and in a second step to a combined loading through gravity and a uniform external magnetic field $$$ {\mathbf{b}}^{\infty }=1\kern0.3em \mathrm{T} $$$.…”

“…These findings have inspired many interesting applications of MREs such magnetically actuated valves, 10 magnetically tunable dampers 11 and vibration isolators 12‐14 as well as micropumps 15 . With matrix materials becoming softer and bodies and structures becoming more compliant, new opportunities for applications open up in medical and biological contexts 16,17 . However, in this subclass of MREs well‐established experimental, numerical and theoretical approaches face new challenges.…”

Exertions of Magnetic Polymer Composites Fabricated via 3D Printing

“…An intact knowledge of the extent to which the values of these properties can be improved is essential to know their potential and to make them workable for different applications. Magnetic polymer composites were characterized for distinct applications in the biomedical field. − The introduction of hydrogels composed of magnetic polymers in biomedical applications improves the biocompatibility of the material. An interesting example in this regard can be cited with the incorporation of magnetic particulates into the PLA matrix, which not only make the actuation mode region specific and spontaneous but also reduce the temperature of activation closer to the temperature of the human body, which was otherwise between 60 °C and 80 °C, greater than the normal body temperature .…”