Rotating magnetic field-controlled fabrication of magnetic hydrogel with spatially disk-like microstructures

Abstract

Composite biomaterials with controllable microstructures play an increasingly important role in tissue engineering and regenerative medicine. Here, we report a magnetic hydrogel composite with disk-like microstructure fabricated by assembly of iron oxide nanoparticles during the gelation process in the presence of rotating magnetic field. It should be mentioned that the iron oxide nanoparticles here were synthesized identically following techniques of Ferumoxytol that is the only inorganic nanodrug approved by FDA for clinical applications. The microstructure of nanoparticles inside the hydrogel was ordered three-dimensionally due to the twist of the aligned chains of magnetic nanoparticles which leads to the lowest state of systematic energy. The size of microstructure can be tuned from several micrometers to tens of micrometers by changing the assembly parameters. With the increase of microstructure size, the magnetothermal anisotropy was also augmented. This result confirmed that the assembly-induced anisotropy can occur even for the several micron aggregates of nanoparticles. The rotating magnetic field-assisted technique is cost-effective, simple and flexible for the fabrication of composite hydrogel with ordered microstructure. We believe it will be favorable for the quick, green and intelligent fabrication of some composite materials.

Vortex fluidic mediated one-step fabrication of polyvinyl alcohol hydrogel films with tunable surface morphologies and enhanced self-healing properties

“…The control of the surface morphology in hydrogels has a potential impact on the development of high-performance devices for biomedical applications, such as tissueengineered scaffolds and systems for drug delivery. Noting that surface morphology provides a unique way of controlling cell-biomaterial interaction and plays a major role in modulating cellular behaviour, such as cell attachment and proliferation during cell culture [46][47][48]. We found that by precisely varying the rotation speed of the VFD tube, PVA hydrogel films with different surface morphologies were readily fabricated.…”

Adaptive iron-based magnetic nanomaterials of high performance for biomedical applications

“…The nanoparticles can form head-to-tail structures to minimize the systematic energy [114]. In particular, the rotating magnetic field composed of two magnets fixed on a motor can result in the formation of disk-like assemblies of magnetic nanoparticles [116]. The process of assembly might be attributed to the coupled interaction of magnetic dipolar force, a torsional force from the rotation field and viscous resistance from the fluid.…”

The Magnetic Nanomaterial Biofunctions in Cancer Diagnosis and Therapy

“…For instance, the nanomaterial's overall particle size must be significantly small to avoid being engulfed by the reticuloendothelial system (RES), a vital nonspecific immune system formed by macrophages residing in tissues and relatively large to avoid kidney clearance. Besides, proper surface modification can reduce the magnetic nanomaterials' surface toxicity and enable them to be enriched in specific regions, a prerequisite in tumor diagnosis and targeted therapy [32]. Furthermore, the appropriate nanomaterials' surface modification exhibits precision characteristics when coated with targeting ligands such as proteins, peptides, antibodies, or other small molecules.…”