Hydrogel Magnetomechanical Actuator Nanoparticles for Wireless Remote Control of Mechanosignaling In Vivo

As a new enabling nanotechnology tool for wireless, target-specific,and long-distance stimulation of mechanoreceptors in vivo, here we present a hydrogel magneto-mechanical actuator (h-MMA)nanoparticle. To allow both deep-tissue penetration of input signalsand efficient force generation, h-MMA integrates a two-step transductionmechanism that converts magnetic anisotropic energy to thermal energywithin its magnetic core (i.e.,Zn0.4Fe2.6O4 nanoparticle cluster)and then to mechanical energy to induce the surrounding polymer (i.e., pNiPMAm) shell contraction, finallydelivering forces to activate targeted mechano-receptors. Weshow that h-MMAs enable on-demand modulation of Notch signaling inboth fluorescence reporter cell lines and a xenograft mouse model,demonstrating its utility as a powerful in vivo perturbationapproach for mechano-biology interrogation in a minimally invasiveand untethered manner.