Location of Magnetic and Fluorescent Nanoparticles Encapsulated inside Giant Liposomes

Harnessing the Therapeutic Potential of Extracellular Vesicles for Biomedical Applications Using Multifunctional Magnetic Nanomaterials

Extracellular vesicles (e.g., exosomes) carrying various biomolecules (e.g., proteins, lipids, and nucleic acids) have rapidly emerged as promising platforms for many biomedical applications. Despite their enormous potential, their heterogeneity in surfaces and sizes, the high complexity of cargo biomolecules, and the inefficient uptake by recipient cells remain critical barriers for their theranostic applications. To address these critical issues, multifunctional nanomaterials, such as magnetic nanomaterials, with their tunable physical, chemical, and biological properties, may play crucial roles in next-generation extracellular vesicles (EV)-based disease diagnosis, drug delivery, tissue engineering, and regenerative medicine. As such, one aims to provide cutting-edge knowledge pertaining to magnetic nanomaterials-facilitated isolation, detection, and delivery of extracellular vesicles and their associated biomolecules. By engaging the fields of extracellular vesicles and magnetic nanomaterials, it is envisioned that their properties can be effectively combined for optimal outcomes in biomedical applications.

Application of magnetic nanoparticles in cell therapy

Fe₃O₄ magnetic nanoparticles (MNPs) are biomedical materials that have been approved by the FDA. To date, MNPs have been developed rapidly in nanomedicine and are of great significance. Stem cells and secretory vesicles can be used for tissue regeneration and repair. In cell therapy, MNPs which interact with external magnetic field are introduced to achieve the purpose of cell directional enrichment, while MRI to monitor cell distribution and drug delivery. This paper reviews the size optimization, response in external magnetic field and biomedical application of MNPs in cell therapy and provides a comprehensive view.

A concise review of metallic nanoparticles encapsulation methods and their potential use in anticancer therapy and medicine

Interest in the use of metallic nanoparticles (NPs) in medicine is constantly increasing. The key challenge to the introduction of NPs into anticancer treatment is to limit the contact of their surface with healthy cells and to enable specific targeting of certain tissues, for example, cancerous cells. These aspects have raised a question whether the recent methods of drug delivery allow restricting the contact of NPs with healthy and/or nontarget cells. NPs can be restricted by encapsulation, which involves entrapping them into organic layers. This review is the first to present the different approaches for the encapsulation of metallic NPs, using liposomes, dendrimers, and proteins. The types and methods of entrapping are shown in an accessible way, enriched with graphics, and the pros and cons of these methods are disputable. Furthermore, the potential uses of NP complexes in medicine are described.

Luminophore and Magnetic Multicore Nanoassemblies for Dual-Mode MRI and Fluorescence Imaging

Nanoassemblies encompass a large variety of systems (organic, crystalline, amorphous and porous). The nanometric size enables these systems to interact with biological entities and cellular organelles of similar dimensions (proteins, cells, …). Over the past 20 years, the exploitation of their singular properties as contrast agents has led to the improvement of medical imaging. The use of nanoprobes also allows the combination of several active units within the same nanostructure, paving the way to multi-imaging. Thus, the nano-object provides various additional information which helps simplify the number of clinical procedures required. In this review, we are interested in the combination between fluorescent units and magnetic nanoparticles to perform dual-mode magnetic resonance imaging (MRI) and fluorescent imaging. The effect of magnetic interaction in multicore iron oxide nanoparticles on the MRI contrast agent properties is highlighted.

Nano-biotinylated liposome-based immunoassay for the ultrasensitive detection of protein biomarker in urine

With the development of proteomics and the continuous discovery of biomarkers of trace proteins, it is important to accurately quantify low abundance protein, especially in urine for clinical diagnostics. In this paper, we reported a novel nano-biotinylated liposome-based immuno-loop-mediated isothermal amplification (LI-LAMP) for the ultrasensitive detection of REG1A (a biomarker for pancreatic ductal adenocarcinoma (PDAC) in urine) with high specificity. The detection range was 1µg/mL to 1fg/mL, with a detection limit of 1fg/mL, and no cross-reactivity was observed to occur in this assay. Compared with the amount of REG1A added, REG1A recovery using this method was 130% and 89%. Detection of REG1A concentrations using the LI-LAMP assay from real samples were in good agreement with those determined using ELISA, and relative deviations were not more than 10%. LI-LAMP shows good potential as a clinical diagnostic assay.

Magnetic field responsive drug release from magnetoliposomes in biological fluids

The magnetically triggered drug release properties of magnetoliposomes are strongly affected by the presence of serum proteins.

Make conjugation simple: a facile approach to integrated nanostructures

We report a facile approach to the conjugation of protein-encapsulated gold fluorescent nanoclusters to the iron oxide nanoparticles through catechol reaction. This method eliminates the use of chemical linkers and can be readily extended to the conjugation of biological molecules and other nanomaterials onto nanoparticle surfaces. The key to the success was producing water-soluble iron oxide nanoparticles with active catechol groups. Further, advanced electron microscopy analysis of the integrated gold nanoclusters and iron oxide nanoparticles provided direct evidence of the presence of a single fluorescent nanocluster per protein template. Interestingly, the integrated nanoparticles exhibited enhanced fluorescent emission in biological media. These studies will provide significantly practical value in chemical conjugation, the development of multifunctional nanostructures, and exploration of multifunctional nanoparticles for biological applications.

Nanoparticle actuated hollow drug delivery vehicles

The trend towards personalized medicine and the long-standing wish to reduce drug consumption and unwanted side effects have been the driving force behind research on drug delivery vehicles that control localization, timing and dose of released cargo. Controlling location and timing of the release allows using more potent drugs as the interaction with the right target is ensured and enables sequential drug release. A particularly desired solution allows for externally triggered release of encapsulated compounds. Externally controlled release can be accomplished if drug delivery vehicles, such as liposomes or polyelectrolyte multilayer capsules, incorporate nanoparticle (NP) actuators. However, close control over the structure of the composite material is necessary to harness this potential. This review describes the assembly and characterization of NP functionalized liposomes and polyelectrolyte multilayer capsules that allow for externally triggered cargo release. Special attention is paid to the relationship between NP stability and the assembly and performance of NP functionalized drug delivery vehicles.

The synthesis and bio-applications of magnetic and fluorescent bifunctional composite nanoparticles

Magnetic-fluorescent composite nanoparticles as a new kind of nanoparticle have attracted much attention in recent years. The composite nanoparticles combine the fluorescent properties, magnetic properties and the physical properties of nano-size, so they can offer a range of potential applications, such as bioseparation and bio-imaging, tumor cell localization, and even cancer treatment. This Minireview will introduce the main synthesis strategies for the fabrication of magnetic-fluorescent composite nanoparticles, the current and potential bio-application of magnetic-fluorescent nanocomposites, including protein and DNA separation and detection, bio-imaging and sorting in vitro and in vivo, drug delivery and the cancer treatment.

Doxorubicin loaded magnetic polymersomes: theranostic nanocarriers for MR imaging and magneto-chemotherapy

Hydrophobically modified maghemite (γ-Fe(2)O(3)) nanoparticles were encapsulated within the membrane of poly(trimethylene carbonate)-b-poly(l-glutamic acid) (PTMC-b-PGA) block copolymer vesicles using a nanoprecipitation process. This formation method gives simple access to highly magnetic nanoparticles (MNPs) (loaded up to 70 wt %) together with good control over the vesicles size (100-400 nm). The simultaneous loading of maghemite nanoparticles and doxorubicin was also achieved by nanoprecipitation. The deformation of the vesicle membrane under an applied magnetic field has been evidenced by small angle neutron scattering. These superparamagnetic hybrid self-assemblies display enhanced contrast properties that open potential applications for magnetic resonance imaging. They can also be guided in a magnetic field gradient. The feasibility of controlled drug release by radio frequency magnetic hyperthermia was demonstrated in the case of encapsulated doxorubicin molecules, showing the viability of the concept of magneto-chemotherapy. These magnetic polymersomes can be used as efficient multifunctional nanocarriers for combined therapy and imaging.

Hydrophobic gold nanoparticle self-assembly with phosphatidylcholine lipid: membrane-loaded and janus vesicles

Hybrids of hydrophobic sub-2-nm-diameter dodecanethiol-coated Au nanoparticles and phosphatidylcholine (PC) lipid vesicles made by extrusion were examined by cryogenic transmission electron microscopy (cryoTEM). The nanoparticles loaded the vesicles as a dense monolayer in the hydrophobic core of the lipid bilayer, without disrupting their structure. Nanoparticle-vesicle hybrids could also be made by a dialysis process, mixing preformed vesicles with detergent-stabilized nanoparticles, but this approach led to vesicles only partially loaded with nanoparticles that segregated into hemispherical domains, forming a Janus vesicle-nanoparticle hybrid structure.

Magneto-mechanical mixing and manipulation of picoliter volumes in vesicles

Superparamagnetic beads in giant unilamellar vesicles are used to facilitate magnetic manipulation, positioning, agitation and mixing of ultrasmall liquid volumes. Vesicles act as leakproof picoliter reaction vessels in an aqueous bulk solution and can be deliberately conveyed by an external magnetic field to a designated position. Upon application of an external magnetic field the beads align to form extended chains. In a rotating magnetic field chains break up into smaller fragments caused by the interplay of viscous friction and magnetic attraction. This process obeys a simple relationship and can be exploited to enhance mixing of the vesicle content and the outer solution or adjacent vesicle volumes exactly at the position of release.

Layer-by-layer assembly of conjugated polyelectrolytes on magnetic nanoparticle surfaces

Composite nanoparticles with magnetic core and fluorescent shell were facilely prepared by the layer-by-layer deposition of conjugated polyelectrolytes over the negatively charged nanoparticles (NPs) of superparamagnetic iron oxide. The alternate assembly of cationic and anionic fluorescent polyelectrolytes leads to reversal in the sign of zeta-potentials. The even numbers of adsorption layer corresponding to the anionic polyelectrolyte (PFS) have negative values (-13 to -24 mV), whereas odd numbers of coating relative to the cationic polyelectrolyte (PFN) have positive values (26 to 28 mV). The composite nanoparticles can respond to both external magnetic field and ultraviolet light excitation. Forster resonance energy transfer (FRET) between oppositely charged polyelectrolytes (PFN and ThPFS) layers was also found, indicating dense packing of the polymer coatings. The fluorescence of the positively charged nanoparticles (NPs/PFN) can be quenched with very high efficiency by a small molecule anionic quencher [Fe(CN)6(4-)], while the same quencher has far less effect on the fluorescence of the negatively charged nanoparticles (NPs/PFN/PFS).