Block copolymer conjugated Au-coated Fe3O4 nanoparticles as vectors for enhancing colloidal stability and cellular uptake

Nanodrugs systems for therapy and diagnosis of esophageal cancer

With the increasing incidence of esophageal cancer, its diagnosis and treatment have become one of the key issues in medical research today. However, the current diagnostic and treatment methods face many unresolved issues, such as low accuracy of early diagnosis, painful treatment process for patients, and high recurrence rate after recovery. Therefore, new methods for the diagnosis and treatment of esophageal cancer need to be further explored, and the rapid development of nanomaterials has brought new ideas for solving this problem. Nanomaterials used as drugs or drug delivery systems possess several advantages, such as high drug capacity, adjustably specific targeting capability, and stable structure, which endow nanomaterials great application potential in cancer therapy. However, even though the nanomaterials have been widely used in cancer therapy, there are still few reviews on their application in esophageal cancer, and systematical overview and analysis are deficient. Herein, we overviewed the application of nanodrug systems in therapy and diagnosis of esophageal cancer and summarized some representative case of their application in diagnosis, chemotherapy, targeted drug, radiotherapy, immunity, surgery and new therapeutic method of esophageal cancer. In addition, the nanomaterials used for therapy of esophageal cancer complications, esophageal stenosis or obstruction and oesophagitis, are also listed here. Finally, the challenge and the future of nanomaterials used in cancer therapy were discussed.

The influence of pure (ligandless) magnetite nanoparticles functionalization on blood gases and electrolytes in acute blood loss

Objective was to compare the effect of functionalization of magnetite (Fe₃O₄) nanoparticles (NPs) with sodium chloride (NaCl), or its combination with ethylmethylhydroxypyrydine succinate (EMHPS) and polyvinylpyrrolidone (PVP) on blood gases and electrolytes in acute blood loss. Ligandless magnetite NPs were synthesized by the electron beam technology and functionalized by mentioned agents. Size of NPs in colloidal solutions Fe₃O₄@NaCl, Fe₃O₄@NaCl@EMHPS, Fe₃O₄@NaCl@PVP, Fe₃O₄@NaCl@EMHPS@PVP (nanosystems 1-4) was determined by dynamic light scattering. In vivo experiments were performed on 27 Wistar rats. Acute blood loss was modeled by removal 25 % circulating blood. Nanosystems 1-4 were administered to animals intaperitoneally after the blood loss with followed determination of blood gases, pH and electrolytes. In blood loss, nanosystems Fe₃O₄@NaCl and Fe₃O₄@NaCl@PVP were able to improve the state of blood gases, pH, and the ratio of sodium/potassium in the blood. So, magnetite NPs with a certain surface modification can promote oxygen transport under hypoxic conditions.

Magnetic Nanoparticle Composites: Synergistic Effects and Applications

Composite materials are made from two or more constituent materials with distinct physical or chemical properties that, when combined, produce a material with characteristics which are at least to some degree different from its individual components. Nanocomposite materials are composed of different materials of which at least one has nanoscale dimensions. Common types of nanocomposites consist of a combination of two different elements, with a nanoparticle that is linked to, or surrounded by, another organic or inorganic material, for example in a core-shell or heterostructure configuration. A general family of nanoparticle composites concerns the coating of a nanoscale material by a polymer, SiO2 or carbon. Other materials, such as graphene or graphene oxide (GO), are used as supports forming composites when nanoscale materials are deposited onto them. In this Review we focus on magnetic nanocomposites, describing their synthetic methods, physical properties and applications. Several types of nanocomposites are presented, according to their composition, morphology or surface functionalization. Their applications are largely due to the synergistic effects that appear thanks to the co-existence of two different materials and to their interface, resulting in properties often better than those of their single-phase components. Applications discussed concern magnetically separable catalysts, water treatment, diagnostics-sensing and biomedicine.

Recent Advances in Magnetite Nanoparticle Functionalization for Nanomedicine

Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe3O4) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated in clinical practice. This article makes a summary of the surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine.

Antifibrotic effects of specific siRNA targeting connective tissue growth factor delivered by polyethyleneimine‑functionalized magnetic iron oxide nanoparticles on LX‑2 cells

Connective tissue growth factor (CTGF) is a possible key determinant of progressive fibrosis. Nanotechnology has been considered as a potential tool for developing novel drug delivery systems for various diseases, including liver fibrosis. The present study aimed to investigate the potential antifibrotic activity of CTGF small interfering RNA (siRNA) mediated by polyethyleneimine (PEI)-functionalized magnetic iron oxide (Fe₃O₄) nanoparticles (NPs) in LX-2 cells. PEI-Fe₃O₄/siRNA complexes were synthesized to facilitate siRNA delivery and were transfected into LX-2 cells. Laser confocal microscopy was employed to investigate the cell uptake of PEI-Fe₃O₄/siRNA complexes. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting were used to verify the effect of gene silencing. The results showed that siRNA-loaded PEI-Fe₃O₄ exhibited low cytotoxicity. The transfection efficiency of PEI-Fe₃O₄/siRNA reached 73.8%, and RT-qPCR and western blotting demonstrated effective gene silencing. These results indicated that CTGF siRNA delivered by PEI-Fe₃O₄ NPs significantly reduces CTGF expression and collagen production in activated LX-2 cells, providing a basis for future in vivo studies.

Platelet-membrane-biomimetic nanoparticles for targeted antitumor drug delivery

BACKGROUND

Nanoscale drug-delivery systems (DDSs) have great promise in tumor diagnosis and treatment. Platelet membrane (PLTM) biomimetic DDSs are expected to enhance retention in vivo and escape uptake by macrophages, as well as minimizing immunogenicity, attributing to the CD47 protein in PLTM sends "don't eat me" signals to macrophages. In addition, P-selectin is overexpressed on the PLTM, which would allow a PLTM-biomimetic DDS to specifically bind to the CD44 receptors upregulated on the surface of cancer cells.

RESULTS

In this study, porous nanoparticles loaded with the anti-cancer drug bufalin (Bu) were prepared from a chitosan oligosaccharide (CS)-poly(lactic-co-glycolic acid) (PLGA) copolymer. These were subsequently coated with platelet membrane (PLTM) to form PLTM-CS-pPLGA/Bu NPs. The PLTM-CS-pPLGA/Bu NPs bear a particle size of ~ 192 nm, and present the same surface proteins as the PLTM. Confocal microscopy and flow cytometry results revealed a greater uptake of PLTM-CS-pPLGA/Bu NPs than uncoated CS-pPLGA/Bu NPs, as a result of the targeted binding of P-selectin on the surface of the PLTM to the CD44 receptors of H22 hepatoma cells. In vivo biodistribution studies in H22-tumor carrying mice revealed that the PLTM-CS-pPLGA NPs accumulated in the tumor, because of a combination of active targeting effect and the EPR effect. The PLTM-CS-pPLGA/Bu NPs led to more effective tumor growth inhibition over other bufalin formulations.

CONCLUSIONS

Platelet membrane biomimetic nanoparticles played a promising targeted treatment of cancer with low side effect.

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

BACKGROUND

Stimuli-responsive polymer materials are a new kind of intelligent materials based on the concept of bionics, which exhibits more significant changes in physicochemical properties upon triggered by tiny environment stimuli, hence providing a good carrier platform for antitumor drug delivery.

RESULTS

Dual stimuli-responsive Fe3O4 graft poly(acrylic acid)-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate) block copolymers (Fe3O4-g-PAA-b-PMAEFC) were engineered and synthesized through a two-step sequential reversible addition-fragmentation chain transfer polymerization route. The characterization was performed by FTIR, 1H NMR, SEC, XRD and TGA techniques. The self-assembly behavior in aqueous solution upon triggered by pH, magnetic and redox stimuli was investigated via zeta potentials, vibration sample magnetometer, cyclic voltammetry, fluorescent spectrometry, dynamic light scattering, XPS, TEM and SEM measurements. The experimental results indicated that the Fe3O4-g-PAA-b-PMAEFC copolymer materials could spontaneously assemble into hybrid magnetic copolymer micromicelles with core-shell structure, and exhibited superparamagnetism, redox and pH stimuli-responsive features. The hybrid copolymer micromicelles were stable and nontoxic, and could entrap hydrophobic anticancer drug, which was in turn swiftly and effectively delivered from the drug-loaded micromicelles at special microenvironments such as acidic pH and high reactive oxygen species.

CONCLUSION

This class of stimuli-responsive copolymer materials is expected to find wide applications in medical science and biology, etc., especially in drug delivery system.