Contents
Introduction
The preparation of Fe3O4 MNPs
Co-precipitation method Thermal decomposition method Hydrothermal method Microemulsion method Other methods
Modification strategies based on Fe3O4 MNPs
Modification strategies based on Fe3O4 NPs for expected dispersibility Modification strategies based on Fe3O4 NPs for hydrophilia Modification strategies based on Fe3O4 NPs for targeting Modification strategies based on Fe3O4 NPs for multi-mode imaging Modification strategies based on Fe3O4 NPs for therapy Modification strategy for drug release carrier Modification strategies for multifunctional platforms of diagnosis and treatment based on Fe3O4 MNPs
Conclusions and outlook
Acknowledgements
References
Introduction
The preparation of Fe3O4 MNPs
Co-precipitation method
Thermal decomposition method
Precursor | T/°C | Surfactant | η | t/h | δ/(°C·min−1) | Size/nm | Shape | State | Ref. |
---|---|---|---|---|---|---|---|---|---|
Iron oleate | 290 | OA | 0 | 1 | 10 | 4–6 | SC | monodisperse, SC | [51] |
320 | OA | 0 | 1, 10 | 10 | 6–10 | spherical | monodisperse, SC | [51] | |
320 | OA | 25:1 | 24 | 10 | 13–24 | spherical & cubic | monodisperse, SC | [51] | |
260 | OA | 2:1 | 24 | 3.3 | 9 | spherical | polydisperse, PC | [37] | |
320 | OA | 2:1 | 0.5 | 3.3 | 12 | spherical | monodisperse, SC | [37] | |
Iron pentacarbonyl | 283 | OA | 2:1 | 1.5 | immediately | 14 | spherical & cubic | monodisperse, SC | [51] |
Iron oxyhydroxide | 320 | OA | 15:1 | 24 | 15 | 22–33 | spherical & facetted | monodisperse, SC | [51] |
Iron acetylacetonate | 300 | OAm | 26:1 | 1 | 20 | 3–6 | spherical | monodisperse, SC | [52] |
265 | OA & OAm | 5:1 a) | 2 | immediately | 9 | spherical & cubic | monodisperse, SC | [53] | |
Iron glucuronate | 320 | OA | 1.2:1 | 0.5 | immediately | 11 | cubic | monodisperse, SC | [54] |
Notes: η, molar ratio of surfactant to precursor; δ, heating rate; OA, oleic acid; OAm, oleyamine; PC, poor crystalline; SC, single crystalline; T, temperature; t, time. a) The molar ratio of OA to OAm in the surfactant is 3:2. |
Hydrothermal method
Microemulsion method
Other methods
Method | Advantages | Disadvantages | Surface property | Ref. |
---|---|---|---|---|
Co-precipitation | simple and easy to operate, low needs of reaction conditions | wide range of particles size and poor dispersity | hydrophilia | [36] |
Thermal decomposition | high degree of crystallinity and narrow distribution of particles size | hydrophobicity of products, danger for operator | hydrophobicity | [37] |
Hydrothermal | high purity and magnetism of products | high requirements for reaction conditions | hydrophilia | [39] |
Microemulsion | simple experimental devices, easy to manipulate | low crystallinity of products, low productivity and poor monodispersity | hydrophilia or hydrophobicity | [38] |
Solvothermal | high degree of crystallinity and monodispersity | hydrophobicity of products | hydrophobicity | [66] |
Sol–gel | simple experimental equipment, good monodispersity | low controllability, release of toxic organic substances during reaction | hydrophobicity | [65] |
Vapor deposition | simple devices, easy to control, high purity and good dispersity | low productivity, high cost and difficult for collection of products | hydrophilia | [32] |
Ultrasound | good dispersity, easy to operate | wide distribution of particle size | hydrophilia | [67] |
Mechanical crushing | low cost, high productivity, simple devices | wide distribution of particle size, large particle size | hydrophilia | [68] |
Modification strategies based on Fe3O4 MNPs
Modification strategies based on Fe3O4 NPs for expected dispersibility
Modification strategies based on Fe3O4 NPs for hydrophilia
Modification strategies based on Fe3O4 NPs for targeting
Fig.3 (a) Schematic drawing of the antiphagocytosis 99mTc-labeled Fe3O4 NPs and the diagnosis principle for tumors. Reproduced with permission from Ref. [110]. (b) Schematic illustration of RIA for diagnosis of small HCC. Reproduced with permission from Ref. [111]. (c) Schematic illustration of dual-ratiometric target-triggered fluorescent probe for diagnosis of tumors. Reproduced with permission from Ref. [112]. |
Modification strategies based on Fe3O4 NPs for multi-mode imaging
Fig.4 (a) The design principle of GdIO NPs. Reproduced with permission from Ref. [114]. (b) The design principle of MnO/Fe3O4 NPs. Reproduced with permission from Ref. [115]. (c) Structure and function of Fe3O4@PEG-PLGA MCs. Reproduced with permission from Ref. [116]. (d) Structure and function of Fe3O4@SiO2-Au-Alexa Fluor 647-cRGD NPs. Reproduced with permission from Ref. [118]. |
Modification strategies based on Fe3O4 NPs for therapy
Modification strategy for drug release carrier
Fig.5 (a) Schematic illustration of Fe3O4@SiO2-Glu NPs synthesis. Reproduced with permission from Ref. [119]. (b) Schematic illustration of MFION-based engineering of MSCs for the recovery post-ischemic stroke. Reproduced with permission from Ref. [120]. (c) Schematic of the formation of AAV-MnMEIO hybrid NPs. Reproduced with permission from Ref. [121]. |
Modification strategies for multifunctional platforms of diagnosis and treatment based on Fe3O4 MNPs
Fig.6 (a) The fabrication and function of Fe3O4/MCPC. Reproduced with permission from Ref. [123]. (b) Schematic illustration of MPNA design concept. Reproduced with permission from Ref. [124]. (c) Schematic illustration of MPNA preparation. Reproduced with permission from Ref. [124]. (d) The fabrication of GSH-responsive magnetic Au NWs. Reproduced with permission from Ref. [125]. (e) The application mechanism of magnetic Au NWs. Reproduced with permission from Ref. [125]. |