Iron oxide nanoparticles for sustained delivery of anticancer agents

Multi-stimuli-responsive magnetic assemblies as tunable releasing carriers

Construction of amphiphilic magnetic nanoparticles (MNPs) by cyclodextrin-based inclusion complexation and the reversible assembly of these MNPs triggered by temperature or redox reagent.

Inorganic nanoparticles engineered to attack bacteria

Antibiotics delivered to bacteria using engineered nanoparticles (NP), offer a powerful and efficient means to kill or control bacteria, especially those already resistant to antibiotics.

How ABA block polymers activate cytochrome c in toluene: molecular dynamics simulation and experimental observation

The temperature responsiveness of ABA-polymer-conjugated Cyt c and its improved dispersion properties at high temperature have been investigated through both simulations and experiments.

Fabrication of Fe3O4@mSiO2 Core-Shell Composite Nanoparticles for Drug Delivery Applications

We report the synthesis of Fe3O4@mSiO2 nanostructures of different meso-silica (mSiO2) shell thickness, their biocompatibility and behaviors for loading and release of a model drug ibuprofen. The composite nanostructures have superparamagnetic magnetite cores of 208 nm average size and meso-silica shells of 15 to 40 nm thickness. A modified Stöber method was used to grow the meso-silica shells over the hydrothermally grown monodispersed magnetite particles. The composite nanoparticles show very promising drug holding and releasing behaviors, which depend on the thickness of meso-silica shell. The biocompatibility of the meso-silica-coated and uncoated magnetite nanoparticles was tested through cytotoxicity assay on breast cancer (MCF-7), ovarian cancer (SKOV3), normal human lung fibroblasts MRC-5, and IMR-90 cells. The high drug holding capacity and reasonable biocompatibility of the nanostructures make them ideal agents for targeted drug delivery applications in human body.

Intracellular delivery of peptide cargos using iron oxide based nanoparticles: studies on antitumor efficacy of a BCL-2 converting peptide, NuBCP-9

Delivering peptides into cells targeting the undruggable oncoproteins is an emerging area in cancer therapeutics. Here we report a novel nanoparticle-based delivery system that can transport therapeutic cargos to the intracellular sites without the need for a cell transduction or penetration domain (CPP). In the present study, we have used iron oxide nanoparticles to deliver an oncopeptide, NuBCP-9, targeting the BCL-2 BH3 domain. Citric acid/2-bromo 2-methylpropanoic acid (CA/BMPA)-capped SPIONs were used to immobilize and deliver the NuBCP-9 peptide to the cancer cells without any noticeable off-target effects. Our results have demonstrated that NuBCP-9-SPIONs efficiently penetrate into cancer cells and bind to its intracellular target protein BCL-2. Moreover, significant inhibition of proliferation and substantial induction of cell death were observed when cancer cells were treated with NuBCP-9-SPIONs at different time intervals. Importantly, the IC50 values for killing of breast cancer cells with NuBCP-9-SPIONs were much lower compared to cells treated with the NuBCP-9 peptide linked with a CPP (Arg-8; NuBCP-9-R8). Molecular and biochemical analyses further supported that NuBCP-9-SPIONs killed breast cancer cells by apoptosis-mediated mechanisms. Furthermore, our data demonstrated that administration of NuBCP-9-SPIONs to mice bearing Ehrlich ascites tumors (EAT) was associated with loss of tumorigenicity and extensive apoptosis in tumor tissues. Taken together, these findings show that a non-CPP-tagged peptide can be successfully delivered to undruggable intracellular oncotargets using SPIONs.

Biological impact of superparamagnetic iron oxide nanoparticles for magnetic particle imaging of head and neck cancer cells

Background

As a tomographic imaging technology, magnetic particle imaging (MPI) allows high spatial resolution and sensitivity, and the possibility to create real-time images by determining the spatial distribution of magnetic particles. To ensure a prospective biosafe application of UL-D (University of Luebeck-Dextran coated superparamagnetic nanoparticles), we evaluated the biocompatibility of superparamagnetic iron oxide nanoparticles (SPIONs), their impact on biological properties, and their cellular uptake using head and neck squamous cancer cells (HNSCCs).

Methods

SPIONs that met specific MPI requirements were synthesized as tracers. Labeling and uptake efficiency were analyzed by hematoxylin and eosin staining and magnetic particle spectrometry. Flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays, and real-time cell analyzer assays were used to investigate apoptosis, proliferation, and the cytokine response of SPION-labeled cells. The production of reactive oxygen species (ROS) was determined using a fluorescent dye. Experimental results were compared to the contrast agent Resovist^®, a standard agent used in MPI.

Results

UL-D nanoparticles and Resovist particles were taken up in vitro by HNSCCs via unspecific phagocytosis followed by cytosolic accumulation. To evaluate toxicity, flow cytometry analysis was performed; results showed that dose- and time-dependent administration of Resovist induced apoptosis whereas cell viability of UL-D-labeled cells was not altered. We observed decreased cell proliferation in response to increased SPION concentrations. An intracellular production of ROS could not be detected, suggesting that the particles did not cause oxidative stress. Tumor necrosis factor alpha (TNF-α) and interleukins IL-6, IL-8, and IL-1β were measured to distinguish inflammatory responses. Only the primary tumor cell line labeled with >0.5 mM Resovist showed a significant increase in IL-1β secretion.

Conclusion

Our data suggest that UL-D SPIONs are a promising tracer material for use in innovative tumor cell analysis in MPI.

Synthesis, characterization and in vitro study of biocompatible cinnamaldehyde functionalized magnetite nanoparticles (CPGF Nps) for hyperthermia and drug delivery applications in breast cancer

Cinnamaldehyde, the bioactive component of the spice cinnamon, and its derivatives have been shown to possess anti-cancer activity against various cancer cell lines. However, its hydrophobic nature invites attention for efficient drug delivery systems that would enhance the bioavailability of cinnamaldehyde without affecting its bioactivity. Here, we report the synthesis of stable aqueous suspension of cinnamaldehyde tagged Fe3O4 nanoparticles capped with glycine and pluronic polymer (CPGF NPs) for their potential application in drug delivery and hyperthermia in breast cancer. The monodispersed superparamagnetic NPs had an average particulate size of ∼ 20 nm. TGA data revealed the drug payload of ∼ 18%. Compared to the free cinnamaldehyde, CPGF NPs reduced the viability of breast cancer cell lines, MCF7 and MDAMB231, at lower doses of cinnamaldehyde suggesting its increased bioavailability and in turn its therapeutic efficacy in the cells. Interestingly, the NPs were non-toxic to the non-cancerous HEK293 and MCF10A cell lines compared to the free cinnamaldehyde. The novelty of CPGF nanoparticulate system was that it could induce cytotoxicity in both ER/PR positive/Her2 negative (MCF7) and ER/PR negative/Her2 negative (MDAMB231) breast cancer cells, the latter being insensitive to most of the chemotherapeutic drugs. The NPs decreased the growth of the breast cancer cells in a dose-dependent manner and altered their migration through reduction in MMP-2 expression. CPGF NPs also decreased the expression of VEGF, an important oncomarker of tumor angiogenesis. They induced apoptosis in breast cancer cells through loss of mitochondrial membrane potential and activation of caspase-3. Interestingly, upon exposure to the radiofrequency waves, the NPs heated up to 41.6 °C within 1 min, suggesting their promise as a magnetic hyperthermia agent. All these findings indicate that CPGF NPs prove to be potential nano-chemotherapeutic agents in breast cancer.

Integrity of (111)In-radiolabeled superparamagnetic iron oxide nanoparticles in the mouse

INTRODUCTION

Iron-oxide nanoparticles can act as contrast agents in magnetic resonance imaging (MRI), while radiolabeling the same platform with nuclear medicine isotopes allows imaging with positron emission tomography (PET) or single-photon emission computed tomography (SPECT), modalities that offer better quantification. For successful translation of these multifunctional imaging platforms to clinical use, it is imperative to evaluate the degree to which the association between radioactive label and iron oxide core remains intact in vivo.

METHODS

We prepared iron oxide nanoparticles stabilized by oleic acid and phospholipids which were further radiolabeled with (59)Fe, (14)C-oleic acid, and (111)In.

RESULTS

Mouse biodistributions showed (111)In preferentially localized in reticuloendothelial organs, liver, spleen and bone. However, there were greater levels of (59)Fe than (111)In in liver and spleen, but lower levels of (14)C.

CONCLUSIONS

While there is some degree of dissociation between the (111)In labeled component of the nanoparticle and the iron oxide core, there is extensive dissociation of the oleic acid component.

Biosafe nanoscale pharmaceutical adjuvant materials

Thanks to developments in the field of nanotechnology over the past decades, more and more biosafe nanoscale materials have become available for use as pharmaceutical adjuvants in medical research. Nanomaterials possess unique properties which could be employed to develop drug carriers with longer circulation time, higher loading capacity, better stability in physiological conditions, controlled drug release, and targeted drug delivery. In this review article, we will review recent progress in the application of representative organic, inorganic and hybrid biosafe nanoscale materials in pharmaceutical research, especially focusing on nanomaterial-based novel drug delivery systems. In addition, we briefly discuss the advantages and notable functions that make these nanomaterials suitable for the design of new medicines; the biosafety of each material discussed in this article is also highlighted to provide a comprehensive understanding of their adjuvant attributes.

5'-Guanosine monophosphate mediated biocompatible porous hydrogel of β-FeOOH-viscoelastic behavior, loading, and release capabilities of freeze-dried gel

The present manuscript reports the characterization, optimization of rheological properties, and loading and release capabilities of 5'-GMP mediated β-FeOOH hydrogel. Circular dichroism (CD) analysis indicates it to contain mainly the left-handed helix similar to that of Z-DNA. The highest viscosity (>300 cP) corresponds to the sample containing 2.5 × 10(-3) mol dm(-3) of 5'-GMP (SP2H). Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) studies indicate the freeze-dried (FD) SP2H to be porous in nature, which is also supported by its high Brunauer-Emmett-Teller (BET) surface area of 226 m(2)/g as compared to that of SP3H (75 m(2)/g). Selected area electron diffraction (SAED) analysis and Raman spectroscopy show it to contain β-FeOOH phase. The FD SP2H exhibits the high swelling ratio (326%) and loading capacity for methylene blue (MB) dye. It displays a controlled and efficient release (>90%) for optimized [MB] (2.5 × 10(-4) mol dm(-3)) in 48 h. The low toxicity of as synthesized FD SP2H nanostructures against MDA-MB-231 (breast cancer cells) up to 100 μg/mL suggests its biocompatible nature. The high porosity, surface area, % swelling, and loading and release performance of the hydrogel indicate its potential for drug delivery and other biological applications.

Polymeric-gold nanohybrids for combined imaging and cancer therapy

Here, the use of folic acid (FA)-functionalized, doxorubicin (DOXO)/superparamagnetic iron oxide nanoparticles (SPION)-loaded poly(lactic-co-glycolic acid) (PLGA)-Au porous shell nanoparticles (NPs) as potential nanoplatforms is reported for targeted multimodal chemo- and photothermal therapy combined with optical and magnetic resonance imaging in cancer. These polymeric-gold nanohybrids (PGNH) are produced by a seeded-growth method using chitosan as an electrostatic "glue" to attach Au seeds to DOXO/SPION-PLGA NPs. In order to determine their potential as theranostic nanoplatforms, their physicochemical properties, cellular uptake, and photothermal and chemotherapeutic efficiencies are tested in vitro using a human cervical cancer (HeLa) cell line. The present NPs show a near-infrared (NIR)-light-triggered release of cargo molecules under illumination and a great capacity to induce localized cell death in a well-focused region. The functionalization of the PGNH NPs with the targeting ligand FA improves their internalization efficiency and specificity. Furthermore, the possibility to guide the PGNH NPs to cancer cells by an external magnetic field is also proven in vitro, which additionally increases the cellular uptake and therapeutic efficiency.

Surfactants present complex joint effects on the toxicities of metal oxide nanoparticles

The potential toxicities of nanoparticles (NPs) have been intensively discussed over the past decade. In addition to their single toxicities, NPs can interact with other environmental chemicals and thereby exert joint effects on biological systems and the environment. The present study investigated the combined toxicities of NPs and surfactants, which are among the chemicals that most likely coexist with NPs. Photobacterium phosphoreum was employed as the model organism. The results indicate that surfactants with different ion types can alter the properties of NPs (i.e., particle size and surface charge) in different ways and present complex joint effects on NP toxicities. Mixtures of different NPs and surfactants exhibited antagonistic, synergistic, and additive effects. In particular, the toxicity of ZnO was observed to result from its dissolved Zn(2+); thus, the joint effects of the ZnO NPs and surfactants can be explained by the interactions between the Zn ions and the surfactants. Our study suggests that the potential hazards caused by mixtures of NPs and surfactants are different from those caused by single NPs. Because surfactants are extensively used in the field of nanotechnology and are likely to coexist with NPs in natural waters, the ecological risk assessments of NPs should consider the impacts of surfactants.

In vitro and in vivo CT imaging using bismuth sulfide modified with a highly biocompatible Pluronic F127

Probe bismuth sulfide modified with Pluronic F127 (Bi2S3-PF127), which has high biocompatibility and dispersibility, is synthesized using triblock copolymer Pluronic F127 to modify hydrophobic Bi2S3 nanoparticles that are prepared by a hot injection method. TEM results show that most of the probe has a length of about 14.85 ± 1.70 nm and a breadth of about 4.79 ± 0.63 nm. After injected into the tail vein of a mouse, the probe has obvious CT contrast enhancement capability from x-ray CT imaging results. Meanwhile, the probe's in vivo toxicity is also studied. It is found that hematoxylin and eosin stains of major organs have no change. A biochemical analysis (alanine aminotransferase and aspartate aminotransferase) prove the probe has no adverse effects. The results of a blood analysis (white blood cell count, red blood cell count, hemoglobin, and platelet count) are also normal. The biological distribution of Bi by ICP-AES shows that most of nanoparticles are cleaned out after injection 48 h, and the circulation half-life of the probe is 5.0 h, suggesting that Bi2S3-PF127 has a long circulation and indicating that the Bi2S3-PF127 probe has good biocompatibility and safety.

Nanotechnology in drug delivery: the need for more cell culture based studies in screening

Advances in biomedical science are leading to upsurge synthesis of nanodelivery systems for drug delivery. The systems were characterized by controlled, targeted and sustained drug delivery ability. Humans are the target of these systems, hence, animals whose systems resembles humans were used to predict outcome. Thus, increasing costs in money and time, plus ethical concerns over animal usage. However, with consideration and planning in experimental conditions, in vitro pharmacological studies of the nanodelivery can mimic the in vivo system. This can function as a simple method to investigate the effect of such materials without endangering animals especially at screening phase.

Calcium-channel blocking and nanoparticles-based drug delivery for treatment of drug-resistant human cancers

Background: Cancer cell chemoresistance is one of the major limitations to successful cancer treatment and one of the factors that is responsible for the possible recurrence of the disease. Here, we aimed to combine a calcium-channel blocker, verapamil, with an alternative delivery of the anti-cancer drug, doxorubicin, using nanostructural materials. This approach could reduce the cellular resistance to chemotherapeutics agents. Results: The outcome of this complex approach on cellular viability was investigated by using various assays in both a time- and concentration-dependent manner: WST-1, flow cytometry cell viability assay, fluorescence microscopy, DNA fragmentation, and TUNEL labeling of apoptotic cells. Conclusion: All of these analytical assays confirmed the ability to reduce the chemoresistance of the cancer cells based on the proposed procedure.

Superparamagnetic Nanoparticles for Atherosclerosis Imaging

The production of magnetic nanoparticles of utmost quality for biomedical imaging requires several steps, from the synthesis of highly crystalline magnetic cores to the attachment of the different molecules on the surface. This last step probably plays the key role in the production of clinically useful nanomaterials. The attachment of the different biomolecules should be performed in a defined and controlled fashion, avoiding the random adsorption of the components that could lead to undesirable byproducts and ill-characterized surface composition. In this work, we review the process of creating new magnetic nanomaterials for imaging, particularly for the detection of atherosclerotic plaque, in vivo. Our focus will be in the different biofunctionalization techniques that we and several other groups have recently developed. Magnetic nanomaterial functionalization should be performed by chemoselective techniques. This approach will facilitate the application of these nanomaterials in the clinic, not as an exception, but as any other pharmacological compound.

Release behavior and toxicity profiles towards leukemia (WEHI-3B) cell lines of 6-mercaptopurine-PEG-coated magnetite nanoparticles delivery system

The coating of an active drug, 6-mercaptopurine, into the iron oxide nanoparticles-polyethylene glycol (FNPs-PEG) in order to form a new nanocomposite, FPEGMP-2, was accomplished using coprecipitation technique. The resulting nanosized with a narrow size distribution magnetic polymeric particles show the superparamagnetic properties with 38.6 emu/g saturation magnetization at room temperature. Fourier transform infrared spectroscopy and the thermal analysis study supported the formation of the nanocomposite and the enhancement of thermal stability in the resulting nanocomposite comparing with its counterpart in free state. The loading of 6-mercaptopurine (MP) in the FPEGMP-2 nanocomposite was estimated to be about 5.6% and the kinetic experimental data properly correlated with the pseudo-second order model. Also, the release of MP from the FPEGMP-2 nanocomposite shows the sustained release manner which is remarkably lower in phosphate buffered solution at pH 7.4 than pH 4.8, due to different release mechanism. The maximum percentage release of MP from the nanocomposite reached about 60% and 97% within about 92 and 74 hours when exposed to pH 7.4 and 4.8, respectively.

Recent advances in superparamagnetic iron oxide nanoparticles for cellular imaging and targeted therapy research

Advances of nanotechnology have led to the development of nanomaterials with both potential diagnostic and therapeutic applications. Among them, superparamagnetic iron oxide (SPIO) nanoparticles have received particular attention. Over the past decade, various SPIOs with unique physicochemical and biological properties have been designed by modifying the particle structure, size and coating. This article reviews the recent advances in preparing SPIOs with novel properties, the way these physicochemical properties of SPIOs influence their interaction with cells, and the development of SPIOs in liver and lymph nodes magnetic resonance imaging (MRI) contrast. Cellular uptake of SPIO can be exploited in a variety of potential clinical applications, including stem cell and inflammation cell tracking and intra-cellular drug delivery to cancerous cells which offers higher intra-cellular concentration. When SPIOs are used as carrier vehicle, additional advantages can be achieved including magnetic targeting and hyperthermia options, as well as monitoring with MRI. Other potential applications of SPIO include magnetofection and gene delivery, targeted retention of labeled stem cells, sentinel lymph nodes mapping, and magnetic force targeting and cell orientation for tissue engineering.

Up-conversion nanoparticle assembled mesoporous silica composites: synthesis, plasmon-enhanced luminescence, and near-infrared light triggered drug release

A facile process for the preparation of multifunctional nanospheres combining several advantages of mesoporous channels, up-conversion (UC) luminescence, and photothermal responses into one single entity is reported. First, Gd2O3:Yb/Er assembled mesoporous silica with 2D hexagonal (MCM-41) and 3D cubic (MCM-48) network have been prepared via a one-step procedure. Then, gold nanocrystals with diameter of 5 nm are integrated with the amino group functionalized nanocomposites. Upon 980 nm near infrared (NIR) laser irradiation, a wavelength-dependent enhancement of the UC intensities is observed due to the surface plasmon resonance (SPR) effect of attached gold nanoparticles. These composites have good biocompatibility and sustained anticancer drug (doxorubicin, DOX) release properties, making it a promising candidate for drug delivery. Particularly, under 980 nm NIR laser irradiation, the green UC emission overlaps the SPR band of gold nanocrystals, which causes a photothermal effect of gold nanocrystals and induces a rapid DOX release from the Au hybrid materials. This DOX loaded multifunctional system has an obvious cytotoxic effect and photothermally killing enhanced effect on SKOV3 ovarian cancer cells. The endocytosis process was also demonstrated through confocal laser scanning microscope (CLSM) images. Such novel multifunctional anticancer drug delivery systems, which combine hyperthermia with the chemotherapeutic drugs by synergistic effect, should be of high potential in cancer therapy.

Engineered magnetic nanoparticles for biomedical applications

In the past decades, magnetic nanoparticles (MNPs) have been used in wide range of diverse applications, ranging from separation to sensing. Here, synthesis and applications of functionalized MNPs in the biomedical field are discussed, in particular in drug delivery, imaging, and cancer therapy, highlighting also recent progresses in the development of multifunctional and stimuli-responsive MNPs. The role of their size, composition, and surface functionalization is analyzed, together with their biocompatibility issues.

Arginine-chitosan- and arginine-polyethylene glycol-conjugated superparamagnetic nanoparticles: Preparation, cytotoxicity and controlled-release

Iron oxide magnetic nanoparticles (MNPs) can be used in targeted drug delivery systems for localized cancer treatment. MNPs coated with biocompatible polymers are useful for delivering anticancer drugs. Iron oxide MNPs were synthesized via co-precipitation method then coated with either chitosan (CS) or polyethylene glycol (PEG) to form CS-MNPs and PEG-MNPs, respectively. Arginine (Arg) was loaded onto both coated nanoparticles to form Arg-CS-MNP and Arg-PEG-MNP nanocomposites. The X-ray diffraction results for the MNPs and the Arg-CS-MNP and Arg-PEG-MNPs nanocomposites indicated that the iron oxide contained pure magnetite. The amount of CS and PEG bound to the MNPs were estimated via thermogravimetric analysis and confirmed via Fourier transform infrared spectroscopy analysis. Arg loading was estimated using UV-vis measurements, which yielded values of 5.5% and 11% for the Arg-CS-MNP and Arg-PEG-MNP nanocomposites, respectively. The release profile of Arg from the nanocomposites followed a pseudo-second-order kinetic model. The cytotoxic effects of the MNPs, Arg-CS-MNPs, and Arg-PEG-MNPs were evaluated in human cervical carcinoma cells (HeLa), mouse embryonic fibroblast cells (3T3) and breast adenocarcinoma cells (MCF-7). The results indicate that the MNPs, Arg-CS-MNPs, and Arg-PEG-MNPs do not exhibit cytotoxicity toward 3T3 and HeLa cells. However, treatment of the MCF-7 cells with the Arg-CS-MNP and Arg-PEG-MNP nanocomposites reduced the cancer cell viability with IC₅₀ values of 48.6 and 42.6 µg/mL, respectively, whereas the MNPs and free Arg did not affect the viability of the MCF-7 cells.

Magnetically separable and recyclable Fe3O4-supported Ag nanocatalysts for reduction of nitro compounds and selective hydration of nitriles to amides in water

As hybrid nanostructures have become more important in many fields of chemistry, Ag nanoparticles (NPs) are being increasingly immobilized onto Fe₃O₄ microspheres in situ. Structural characterization reveals that the Ag NPs are uniformly immobilized in the Fe₃O₄ microsphere-based supports. Moreover, Ag NPs are more stable in the hybrid structure than in the naked state and show high catalytic activity for the reduction of nitro compounds and hydration of nitriles to amides in water. The Fe₃O₄ microspheres were recycled several times using an external magnet.

Novel kojic acid-polymer-based magnetic nanocomposites for medical applications

Iron oxide magnetic nanoparticles (MNPs) were synthesized by the coprecipitation of iron salts in sodium hydroxide followed by coating separately with chitosan (CS) and polyethylene glycol (PEG) to form CS-MNPs and PEG-MNPs nanoparticles, respectively. They were then loaded with kojic acid (KA), a pharmacologically bioactive natural compound, to form KA-CS-MNPs and KA-PEG-MNPs nanocomposites, respectively. The MNPs and their nanocomposites were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, vibrating sample magnetometry, and scanning electron microscopy. The powder X-ray diffraction data suggest that all formulations consisted of highly crystalline, pure magnetite Fe₃O₄. The Fourier transform infrared spectroscopy and thermogravimetric analysis confirmed the presence of both polymers and KA in the nanocomposites. Magnetization curves showed that both nanocomposites (KA-CS-MNPs and KA-PEG-MNPs) were superparamagnetic with saturation magnetizations of 8.1 emu/g and 26.4 emu/g, respectively. The KA drug loading was estimated using ultraviolet–visible spectroscopy, which gave a loading of 12.2% and 8.3% for the KA-CS-MNPs and KA-PEG-MNPs nanocomposites, respectively. The release profile of the KA from the nanocomposites followed a pseudo second-order kinetic model. The agar diffusion test was performed to evaluate the antimicrobial activity for both KA-CS-MNPs and KA-PEG-MNPs nanocomposites against a number of microorganisms using two Gram-positive (methicillin-resistant Staphylococcus aureus and Bacillus subtilis) and one Gram-negative (Salmonella enterica) species, and showed some antibacterial activity, which could be enhanced in future studies by optimizing drug loading. This study provided evidence for the promise for the further investigation of the possible beneficial biological activities of KA and both KA-CS-MNPs and KA-PEG-MNPs nanocomposites in nanopharmaceutical applications.

Novel biodegradable heparin-coated nanocomposite system for targeted drug delivery

HP–SPIO NPs (42 nm) were formulated by co-precipitation. Doxorubicin and paclitaxel were loaded into the SPIO NP core. HP–SPIO NPs had sustained release of DOX (87%) and PTX (75%) at pH 6.0. Drug loaded HP–SPIO NPs caused 95 and 84%, and 85 and 77% apoptosis in A2780 and OVCAR-3 cells, respectively. DOX–HP–SPIO NPs and PTX–HP–SPIO NPs caused a sharp decrease in bcl-2 and survivin proteins.

Impact of Serum Proteins on MRI Contrast Agents: Cellular Binding and T2 relaxation

Superparamagnetic iron oxide nanoparticles (SPIONs) used as MRI contrast agents or for theranostic applications encounter a complex mixture of extracellular proteins that adsorb on the SPION surface forming a protein corona. Our goal was to understand how cellular binding and T₂ relaxation times are affected by this protein corona. Our studies focused on carboxymethyl dextran-modified SPIONs, chosen for their similarity to Resovist SPIONs used to detect liver lesions. Using a combination of fluorescence microscopy and flow cytometry, we find that the cellular binding of SPIONs to both macrophages and epithelial cells is significantly inhibited by serum proteins. To determine if this decreased binding is due to the iron oxide core or the carboxymethyl dextran surface coating, we functionalized polystyrene nanoparticles with a similar carboxymethyl dextran coating. We find a comparable decrease in cellular binding for the carboxymethyl dextran-polystyrene nanoparticles indicating that the carbohydrate surface modification is the key factor in SPION-cell interactions. NMR measurements showed that T₂ relaxation times are not affected by corona formation. These results indicate that SPIONs have a decreased binding to cells under physiological conditions, possibly limiting their use in theranostic applications. We expect these results will be useful in the design of SPIONs for future diagnostic and therapeutic applications.

NIR-light active hybrid nanoparticles for combined imaging and bimodal therapy of cancerous cells

Multifunctional hybrid polymeric-based nanoplatforms for simultaneous fluorescence and magnetic resonance imaging and multimodal chemo- and phothermal therapies.

Ormosil nanoparticles as a sustained-release drug delivery vehicle

Tem images (above) and release profiles (below) of encapsulated drug from ormosil nanoparticles with small (orm-s), medium (orm-m) and large (orm-l) sizes.

Anti-ABCG2 monoclonal antibody in combination with paclitaxel nanoparticles against cancer stem-like cell activity in multiple myeloma

Aim: To investigate the effects of anti-ABCG2 monoclonal antibodies (mAbs) in combination with paclitaxel iron oxide nanoparticles (PTX-NPs) on CD138-CD34- multiple myeloma (MM) cancer stem cells (CSCs) in JJN3 cells. Materials & methods: PTX-NPs were prepared using the hydrophobic interaction of the polyoxypropylene chain and oleic acid on the surface of iron oxide NPs and were targeted to the ABCG2 transporter overexpressing MM CSCs with mAbs. Results: The data showed that MM CSCs have strong drug resistance and tumorigenicity compared with non-MM CSCs. PTX-NPs combined with mAbs led to a significant reduction in the tumor volume, a visible alleviation of lytic bone lesions and a markedly increased survival rate in contrast to using a single agent in MM CSCs when it was transplanted to nonobese diabetic/severe combined immunodeficiency mice. Conclusion: This study is the first to report on the anti-MM CSC activity by PTX-NPs as a single agent or used together with anti-ABCG2 mAbs to treat MM. These findings provide a rationale for future clinical trials.

Original submitted 18 June 2012; Revised submitted 29 November 2012; Published online 27 March 2013

Chemical and magnetic functionalization of graphene oxide as a route to enhance its biocompatibility

The novel approach for deposition of iron oxide nanoparticles with narrow size distribution supported on different sized graphene oxide was reported. Two different samples with different size distributions of graphene oxide (0.5 to 7 μm and 1 to 3 μm) were selectively prepared, and the influence of the flake size distribution on the mitochondrial activity of L929 with WST1 assay in vitro study was also evaluated. Little reduction of mitochondrial activity of the GO-Fe3O4 samples with broader size distribution (0.5 to 7 μm) was observed. The pristine GO samples (0.5 to 7 μm) in the highest concentrations reduced the mitochondrial activity significantly. For GO-Fe3O4 samples with narrower size distribution, the best biocompatibility was noticed at concentration 12.5 μg/mL. The highest reduction of cell viability was noted at a dose 100 μg/mL for GO (1 to 3 μm). It is worth noting that the chemical functionalization of GO and Fe3O4 is a way to enhance the biocompatibility and makes the system independent of the size distribution of graphene oxide.

Additive effect of zinc oxide nanoparticles and isoorientin on apoptosis in human hepatoma cell line

Metal nanomaterial could effectively decrease tumour resistance to anti-cancer drugs. In this paper, we have explored the synergistic effect and mechanisms of zinc oxide nanoparticles (ZnO Nps) and isoorientin (ISO) on cytotoxicity in human hepatoma (HepG2) cells. The results showed that ZnO Nps could exert dose- and time-dependent cytotoxicity in HepG2 cells, and the combining treatment resulted in a greater cytotoxicity than single treatment. ZnO Nps could synergistically potentiate ISO to induce apoptosis through resulting in mitochondrial dysfunction, inhibiting the phosphorylation of Akt and ERK1/2, and enhancing the phosphorylation of JNK and P38. Additionally, ZnO Nps were uptaked by cells through endocytic pathway and it enhanced the cellular uptake of ISO, while no significant injury was found in normal liver cells after the combined treatment. These results suggest that the combination of metal nanoparticle with anti-cancer drugs may provide a promising alternative for novel cancer treatments.