Polymer-based encapsulation techniques of MNPs
| Methods | Procedure | Description | Reference |
|---|---|---|---|
| Nanoprecipitation | Dropwise addition of organic solution containing preformed polymer and MNPs into an aqueous phase with or without surfactant, under moderate agitation, the nanocapsules are instantaneously formed on the interface of both phases | Two phases are miscible Organic solvents are highly volatile Organic phase can be a mixed solvent Aqueous phase can be a mixed non-solvent | 81 |
| SEE | It consists of simple emulsion formation, solvent evaporation, polymer precipitation, and particles formation | There are oil/water and water/oil methods Organic phase should be non-miscible but can dissolve polymers Particle characteristics are controlled by adjusting procedure parameters, such as organic/water ratio, surfactant, stirring rate, polymer amount, and evaporation rate | 82 |
| DEE | Primary emulsion: dispersion of an aqueous phase containing MNPs in a non-miscible organic solvent under ultrasound and surfactant Second emulsion: the primary dispersion is added to a second solution containing the stabilizing agent under sonication Nanocapsules formation: NPs are obtained after evaporation of the solvents | It is classified as W/O/W or O/W/O emulsion It is suitable for the co-encapsulation of both hydrophilic and hydrophobic drugs and/or MNPs | 83 |
| LBL | LBL is a stepwise adsorption and assembly process based on spontaneous electrostatic attraction between oppositely charged components at supersaturating polyelectrolyte concentration, which leads to the adsorption of polyelectrolyte onto an oppositely charged particles surface | It is possible to control the size, shape, and thickness of multilayer nanocapsules The polymer should have sufficiently charged groups to provide stable adsorption on the oppositely charged surface Besides electrostatic interaction, hydrogen bonding and covalent bonding are also drivers for multilayer nanocapsule preparation | 84 |
NPs, nanoparticles; MNPs, magnetic nanoparticles; W/O/W, water-oil-water; O/W/O, oil-water-oil.