Nowadays controlling cellular responses and function of biological molecules is becoming one of the prime areas of focus in biomedical field. In this investigation, an attempt is made to generate in situ charge in bioactive glass (BAG) by incorporating BiFeO3 (BF, a multiferroic material). It is hypothesized that BF in BAG can accelerate cellular activities for rapid tissue healing with externally applied magnetic field due to in situ polarization. BAG composites with different amounts of BF (2 to 15 wt%) are prepared using ball milling followed by pressing and sintering. The composites are characterized in terms of microstructures, constituent phases, magnetic, and electrical properties. Further, in vitro cytotoxicity studies are performed to evaluate the influence of in situ polarization by culturing mouse preosteoblast cells (MC3T3) on BAG‐BF composites under different external magnetic field treatments. These in vitro cell‐materials interaction studies demonstrate that magnetic field strengths of 200 or 350 mT exposed for 30 min/day can enhance cell viability and proliferation on these composites up to three times. Hence, the authors expect that this investigation will enable further developments to extend the application of multiferroics in bone tissue engineering.

Developing materials with remote controllability of macroscale ligand presentation can mimic extracellular matrix (ECM) remodeling to regulate cellular adhesion in vivo. Herein, we designed charged mobile nanoligands with superparamagnetic nanomaterials amine-functionalized and conjugated with polyethylene glycol linker and negatively charged RGD ligand. We coupled negatively a charged nanoligand to a positively charged substrate by optimizing electrostatic interactions to allow reversible planar movement. We demonstrate the imaging of both macroscale and in situ nanoscale nanoligand movement by magnetically attracting charged nanoligand to manipulate macroscale ligand density. We show that in situ magnetic control of attracting charged nanoligand facilitates stem cell adhesion, both in vitro and in vivo, with reversible control. Furthermore, we unravel that in situ magnetic attraction of charged nanoligand stimulates mechanosensing-mediated differentiation of stem cells. This remote controllability of ECM-mimicking reversible ligand variations is promising for regulating diverse reparative cellular processes in vivo.

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