A Novel Magnetic Hydrogel with Aligned Magnetic Colloidal Assemblies Showing Controllable Enhancement of Magnetothermal Effect in the Presence of Alternating Magnetic Field

Abstract

A novel magnetic hydrogel is formed via the field-directed assembly of magnetic nanomaterials during the gelation process. The novel magnetic hydrogel exhibits direction-dependent thermogenesis in an alternating magnetic field. The specific absorption rate value in the direction along the assemblies can be 2.1-fold as much as that in the direction normal to the assemblies while the heating rate is 6-8-fold. Due to the anisotropic thermogenesis, the novel magnetic hydrogel also shows a direction-dependent release of drugs that has a 3.4-fold difference between the two directions.

Study of the Dependency of the Specific Power Absorption Rate on Several Characteristics of the Excitation Magnetic Signal when Irradiating a SPION-containing Ferrofluid

“…This figure can be normalized again to remove the extensive effect of the amount of iron oxide by eliminating its weight as follows: (11) It is easy to see then, that the commonly used SAR is and our LER/gr relates each other as follows: (12) The obtained values are represented in Fig. 8 for 1 MHz.…”

“…Brownian relaxation produces heat by friction between SPIONs and a viscous fluid; particles are free enough to be able to rotate following the main alternating magnetic field. The other process involves rotation of the magnetic moment of each particle following the applied magnetic field and is known as Néel relaxation [3,8,10,11]. Brownian relaxation is characterized by the parameter τ B (s) whilst Néel relaxation is characterized by τ N (s).…”

Bioinspired Nanocomposite Hydrogels with Highly Ordered Structures

“…The microscopic linear aligned distribution of 0D magnetic nanoparticles that was inside the hydrogels was characterized by SEM and high-resolution Micro-CT. Reproduced with permission. [53] Copyright 2015, Wiley-VCH. b) Schematic representation of the protocol for preparing magnetically aligned hydrogels that contain 1D carbon nanotubes.…”

“…[52][53][54] These nanoparticles can be mixed into hydrogel precursor solutions. An external magnetic field can control the aggregation of magnetic particles to form the ordered structures in nanocomposite hydrogels.…”

“…A recent work has reported a novel magnetic hydrogel with aligned magnetic nanoparticles (Figure 2a). [53] In a magnetostatic field, magnetic nanoparticles were aligned in monomer solutions, and then hydrogels with aligned structures were prepared by thermal-triggered gelation. Because the hard nanoparticles were arrayed in a certain direction, the mechanical properties of these magnetic hydrogels were anisotropic.…”