Multi-stimuli-responsive magnetic assemblies as tunable releasing carriers

Abstract

A novel approach has been developed to prepare the magnetic micelles. Polyethylene glycol (PEG) and poly(N-isopropylacrylamide) (PNIPAM) are firstly attached on the surface of the magnetic nanoparticle via the host-guest inclusion between ferrocene groups (Fc) and b-cyclodextrin (b-CD). Then the resulting MNPs became amphiphilic in water above the LCST of PNIPAM and self-assembled into magnetomicelles with a size of 250 nm. These hybrid micelles show high loading capacity for anticancer drug (DOX) and high saturation magnetization simultaneously. Furthermore, these micelles could disassemble under the effects of oxidant or temperature, providing an opportunity to fine-tune the release properties of the encapsulated drug in response to temperature, H 2 O 2 or pH independently, or a combined effect of multiple stimuli.Taking other advantages of magnetic carriers, such as high sensitivity to the external magnetic field, contrast effect to magnetic resonance, and magnetic hyperthermia, the micelles developed by this study show great potential application in cancer treatment.

Dual stimuli-responsive Fe3O4 graft poly(acrylic acid)-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate) copolymer micromicelles: surface RAFT synthesis, self-assembly and drug release applications

“…4-Cyano-4(thiobenzoylthio)pentanoic acid (CPADB, 97%), a RAFT chain transfer agent (CTA), was supplied by the Strem Chemicals, Inc., USA. 1-Hydroxybenzotriazole (HOBT, 97%) was used as a protective agent of amido bonds [ 53 , 54 ] and purchased from the Shanghai Macklin Biochemical Co., Ltd., China. 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl, 98%) as dehydrant was provided by the Aladdin Industrial Corp., Shanghai, China.…”

Screening of lipase inhibitors from Scutellaria baicalensis extract using lipase immobilized on magnetic nanoparticles and study on the inhibitory mechanism

“…TEM image revealed that there were aggregations of the particles, while the DLS data presents the hydrodynamic radius in the aqueous dispersions. Therefore, the diameter of Fe 3 O 4 -PPL obtained by DLS was slightly greater than using TEM [34]. In our previous study, we have reported the detailed characteristics of lipase-immobilized MNPs.…”

Semi‐IPNs with Moisture‐Triggered Shape Memory and Self‐Healing Properties

“…The weight ratio of grafted β‐CD in β‐CD‐Al 2 O 3 was 18.64% according to the thermogravimetric analysis (Figure S4d, Supporting Information), which corresponds to about 3710 β‐CD molecules per Al 2 O 3 NP (calculated according to ref. ).…”

“…The synthetic route of PVP/p(HEMA-co-BA) semi-IPNs is shown in Figure 1a Figure S4d, Supporting Information), which corresponds to about 3710 β-CD molecules per Al 2 O 3 NP (calculated according to ref. [32] ).…”