Pulse Magnetic Fields Induced Drug Release from Gold Coated Magnetic Nanoparticle Decorated Liposomes

Abstract

Magnetic nanoparticle-assisted drug release from liposomes is an important way to enhance the functionality/usefulness of liposomes. This work demonstrates an approach how to integrate magnetic nanoparticles with liposomes with the assistance of gold–thiol chemistry. The gold coated magnetic particles cover the thiolated liposomes from the outside, which removes the competition of the drug molecules and the triggering magnetic particles to free the inner space of the liposomes when compared to previous magneto liposome formulations. The liposome consists of dipalmitoyl phosphatidylcholine (DPPC) combined with distearoylphosphatidylcholine (DSPC) in addition to regular cholesterol or cholesterol-PEG-SH. Permeability assays and electron microscopy images show efficient coupling between the liposomes and nanoparticles in the presence of thiol groups without compromising the functionality of the liposomes. The nanoparticles such as gold nanoparticles, gold coated iron oxide nanoparticles and bare iron oxide nanoparticles are added following the model drug encapsulation. The efficient coupling between the gold coated nanoparticles (NPs) and the thiolate liposomes is evidenced by the shift in transition temperature of the thiolated liposomes. The addition of magnetically triggerable nanoparticles externally makes the entire interior of liposomes available for drug loading. The drug release efficiencies of these liposomes/NPs complexes were compared under exposure to pulsed magnetic fields. The results indicate up to 20% of the drug can be released in short time, which is comparable in efficiency to previous studies performed when magnetic NPs were located inside liposomes. Interestingly, the liposomes were found to exhibit variations in release efficiency based on different dilution media which is attributed to an osmotic pressure effect on liposomal stability.

Updates on Responsive Drug Delivery Based on Liposome Vehicles for Cancer Treatment

“…These properties were used by Acharya and Chikan to enhance the functionality of drug-loaded liposomes made of DPPC/DSPC/Cholesterol-PEG-SH particles covered with gold-coated iron oxide NPs. The drug-release efficiency of these formulations under exposure to pulsed magnetic fields indicated that up to 20% of the drug can be released in a short time, compared to bare gold-covered or only iron oxide-coated liposome conjugates [ 180 ]. Except for SPIONs and gold NPs, Dai et al proposed hyperthermia-triggered local drug release by encapsulating responsive magnetic ammonium bicarbonate with Dox in liposomes with a particle size of about 210 nm.…”

Magnetoliposomes: recent advances in the field of controlled drug delivery

“…These systems can be fabricated either through AMLs encapsulating core/shell magnetic/plasmonic nanoparticles [15], or through the incorporation of plasmonic and magnetic nanoparticles in different compartments of the liposomes (e.g. magnetic nanoparticles in the inner aqueous lumen and plasmonic nanoparticles bonded to the liposome surface) [28]. Figure 1 summarizes the main architectures of magnetoliposomes.…”

“…The embedding of nanoparticles in the membrane surpasses AMLs limitations, as it enables the direct heating of the membrane, though the nanoparticle encapsulation efficiency is limited by the nanoparticle's size [22,30]. Although less explored, the nanoparticle-decorated magnetoliposomes make the entire inner cavity of liposomes available for drug loading and enables higher drug release efficiency/trigger [28], besides the potential use of sequential and complementary strategies (magnetic hyperthermia and photothermia). For example, Salvatore et al [27] developed magnetoliposomes comprised of iron oxide nanoparticles embedded in the membrane and bonded to the membrane surface through double-stranded DNA conjugated with a cholesteryl unit.…”

“…Other methods have also been explored to trigger the fast release of the liposomes' payload, such as the use of short magnetic pulses [28] or pulsed electromagnetic fields [49]. A strategy that has been recently explored consists of the photothermal effect upon laser irradiation of the nanoparticles with near-infrared (NIR, 700 -1000 nm) light [8,50].…”

Facile one-pot synthesis of γ-Fe2O3 nanoparticles by inductive heating

“…3,[5][6][7][8][9][10] Because of these unique properties, g-Fe 2 O 3 NPs are used in magnetic resonance imaging (MRI) contrast enhancement, bio-magnetic separation, hyperthermia treatment and magnetic drug targeting, multi-terabyte storage, catalysis, biosensors, bio-separation, and thermoablation. [11][12][13][14][15][16][17][18] The most common method to synthesize colloidal g-Fe 2 O 3 NPs is the HI method. 19,20 In this technique, small amounts of precursor molecules are injected into a hot boiling solvent, which results in rapid decomposition of the molecular precursors thus producing inorganic nanomaterials (oxides, and semiconductors).…”