A Magneto‐Responsive Hydrogel System for the Dynamic Mechano‐Modulation of Stem Cell Niche

Abstract

The biophysical microenvironment of cells dynamically evolves during embryonic development, leading to defined tissue specification. A versatile and highly adaptive magneto‐responsive hydrogel system composed of magnetic nanorods (MNRs) and a stress‐responsive polymeric matrix is developed to dynamically regulate the physical stem cell niche. The anisotropic magnetic/shape factor of nanorods is utilized to maximize the strains on the polymeric network, thus regulating the hydrogel modulus in a physiologically relevant range under a minimal magnitude of the applied magnetic fields below 4.5 mT. More significantly, the pre‐alignment of MNRs induces greater collective strains on the polymeric network, resulting in a superior stiffening range, over a 500% increase as compared to that with randomly oriented nanorods. The pre‐alignment of nanorods also enables a fast and reversible response under a magnetic field of the opposite polarity as well as spatially controlled heterogeneity of modulus within the hydrogel by applying anisotropic magnetic fields. The mechano‐modulative capability of this system is validated by a mechanotransduction model with human‐induced pluripotent stem cells where the locally controlled hydrogel modulus regulates the activation of mechano‐sensitive signaling mediators and subsequent stem cell differentiation. Therefore, this magneto‐responsive hydrogel system provides a platform to investigate various cellular behaviors under dynamic mechanical microenvironments.

Advances in hydrogels for the treatment of periodontitis

“…In the experimental phase, scholars often stop at cellular, animal experiments, however, the validation of human models for clinical purposes is very urgent. Furthermore, various physical and chemical methods are being gradually applied jointly with hydrogels, such as ultrasound-responsive hydrogels, [129][130][131] infrared light-responsive hydrogels, 132,133 magnetic response, [134][135][136] etc. All these methods can further broaden the application of hydrogels in the periodontal field and lay the theoretical foundation for multifunctional multi-technology hydrogels here.…”

Magnetic nanoparticles for nanowarming: seeking a fine balance between heating performance and biocompatibility

“…[48][49][50] Yet, it should be noted that for nanowarming applications, any movement of magnetic nanoparticles under a magnetic field must be carefully controlled to avoid irreversible mechanical damage to normal cells. 51,52 Although these strategies hold promise, it is crucial to conduct further in vivo investigations to establish their feasibility and safety.…”

Lifelike Transformative Materials for Biohybrid Implants: Inspired by Nature, Driven by Technology

“…[29b,108] Magnetic hydrogels also provide a platform for the remote stimulation of cells. [109] Together with the potential to modify the architecture [107] and mechanics [109,110] of biohybrid materials remotely, this opens new horizons for the noninvasive control of implants in vivo. The full potential of materials functionalized with magnetic nanoparticles can be exploited in combination with their use as tracers for magnetic particle imaging, a novel preclinical imaging technique.…”