The application of Fe 3 O 4 nanoparticles in cancer research: A new strategy to inhibit drug resistance

Vinorelbine-loaded multifunctional magnetic nanoparticles as anticancer drug delivery systems: synthesis, characterization, and in vitro release study

In this study, a multifunctional therapeutic agent combining chemotherapy and photothermal therapy on a single platform has been developed in the form of vinorelbine-loaded polydopamine-coated iron oxide nanoparticles. Vinorelbine (VNB) is loaded on the surface of iron oxide nanoparticles produced by a solvothermal technique after coating with polydopamine (PDA) with varying weight ratios as a result of dopamine polymerisation and covalent bonding of thiol-polyethylene glycol (SH-PEG). The VNB/PDA/Fe3O4 nanoparticles have a saturation magnetisation value of 60.40 emu/g in vibrating sample magnetometry, which proves their magnetisation. Vinorelbine, which is used as an effective cancer therapy agent, is included in the nanocomposite structure, and in vitro drug release studies under different pH conditions (pH 5.5 and 7.4) and photothermal activity at 808 nm NIR laser irradiation are investigated. The comprehensive integration of precise multifunctional nanoparticles design, magnetic response, and controlled drug release with photothermal effect brings a different perspective to advanced cancer treatment research.

Green and sustainable synthesis of nanomaterials: Recent advancements and limitations

Nanomaterials have been widely used in diverse fields of research such as engineering, biomedical science, energy, and environment. At present, chemical and physical methods are the main methods for large-scale synthesis of nanomaterials, but these methods have adverse effects on the environment, and health issues, consume more energy, and are expensive. The green synthesis of nanoparticles is a promising and environmentally friendly approach to producing materials with unique properties. Natural reagents such as herbs, bacteria, fungi, and agricultural waste are used in the green synthesis of nanomaterials instead of hazardous chemicals and reduce the carbon footprint of the synthesis process. Green synthesis of nanomaterials is highly beneficial compared to traditional methods due to its low cost, negligible pollution level, and safety for the environment and human health. Nanoparticles possess enhanced thermal and electrical conductivity, catalytic activity, and biocompatibility, making them highly attractive for a range of applications, including catalysis, energy storage, optics, biological labeling, and cancer therapy. This review article provides a comprehensive overview of recent advancements in the green synthesis routes of different types of nanomaterials, including metal oxide-based, inert metal-based, carbon-based, and composite-based nanoparticles. Moreover, we discuss the various applications of nanoparticles, emphasizing their potential to revolutionize fields such as medicine, electronics energy, and the environment. The factors affecting the green synthesis of nanomaterials, and their limitations are also pointed out to decide the direction of this research field, Overall, this paper highlights the importance of green synthesis in promoting sustainable development in various industries.

Magnetoresistance Properties of Red Blood Cells in Plasma Combined with Several Magnetic Beads Passing Two Cu Electrodes

In recent years, research has been intensively carried out on the applicability of magnetic beads (MBs) and magnetic nanoparticles coupled to biological objects such as red blood cells (RBCs). The magnetoresistance (MR) of a solution of RBCs and MBs (RBCs+MBs) was evaluated when MBs migrated in the presence or absence of an external magnetic field. The pattern of distribution of the MBs, which were homogeneously suspended in deionized distilled water, varied depending on the magnitude of the external magnetic field applied between the Cu electrodes connected to the two terminals. As the magnitude of the external magnetic field is increased or decreased, MBs are split on both sides and evenly mixed, respectively. The ratios (ΔMR/MR) versus an external magnetic field for the solutions of only MBs and a mixed RBCs+MBs were -33.4% and -27.4% at ±30 Oe and ±46 Oe of coercive fields, respectively. These results show that a solution of RBCs+MBs can act like a high-resolution biosensor that detects the oxygenation state of RBCs.

Application of ZnO/CNT@Fe3O4nanocomposite in amplifying the anti-leukemic effect of imatinib: a novel strategy to adjuvant therapy in chronic myeloid leukemia

The advent of tyrosine kinase inhibitors (TKI) in the therapeutic protocols of chronic myeloid leukemia (CML) sparked a flame of hope for patients to finally reach to the milestone of the complete remission. However, by the different mutations bypassing the effectiveness of Imatinib, a powerful impetus has emerged to bring more efficient agents into the field of treatment. The results of the present study declared that the companionship of our synthesized ZnO/CNT@Fe3O4 nanocomposite with Imatinib was able to more efficiently decrease the survival of CML-derived K562 cells probably through inducing reactive oxygen species (ROS)-dependent apoptosis. We also found a superior cytotoxicity in the presence of a well-known autophagy inhibitor, indicating that the apoptotic effect of this treatment was probably enhanced through the suppression of autophagy. Investigating the molecular mechanisms involved in the growth-suppressive effect of ZnO/CNT@Fe3O4-plus-Imatinib clarified that the up-regulation of SIRT1 ceased the progression of the cell cycle, foremost by increasing the expression of p21 and p27 cyclin-dependent kinase inhibitors. Notably, we reported for the first time that either direct or indirect suppression of c-Myc resulted in an enhanced anti-leukemic effect; suggesting that the overexpression of c-Myc could play a contributory role in attenuating the efficacy of ZnO/CNT@Fe3O4-plus-Imatinib in K562. Given to the established efficacy of ZnO/CNT@Fe3O4 in CML cells, our preclinical results suggest that the application of this nanocomposite is an appealing strategy to boost the anti-leukemic effect of TKIs, which should be further studied in combination with other anti-cancer agents either in hematologic malignancies or solid tumors.

Synthesis, Electrochemical Studies, and Antimicrobial Properties of Fe3O4 Nanoparticles from Callistemon viminalis Plant Extracts

Less toxic, environmentally safe green-mediated iron (III) oxide nanoparticles (Fe₃O₄-NP) synthesized using Callistemon viminalis (C. viminalis) leaf (Fe₃O₄-NPL) and flower (Fe₃O₄-NPF) extracts is reported in this work for the first time. Total flavonoids and phenols present in the plant extracts were determined. Characterization of the nanoparticles was carried out using Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible spectroscopy (UV–VIS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Malvern zeta sizer. Other properties of the nanoparticles were investigated using the thermogravimetric analyser and cyclic voltammetry. The average particle sizes obtained for Fe₃O₄-NPL and Fe₃O₄-NPF were 17.91 nm and 27.93 nm, respectively. Fe₃O₄-NPL exhibited an excellent electrochemical activity when compared with Fe₃O₄-NPF based on a stability study using cyclic voltammetry and regression value. Additionally, Fe₃O₄-NPF displayed excellent antimicrobial activity against Bacillus cereus, Salmonella enteritidis, and Vibrio cholerae with zones of inhibition of 13, 15, and 25 mm, respectively. Simple, cheap, and less toxic green-mediated iron (III) oxide nanoparticles synthesized from C. viminalis leaf (Fe₃O₄-NPL) and flower (Fe₃O₄-NPF) extracts hold the potential of being used to control the activity of pathogenic bacteria of health importance and as an electrochemical sensor for both biological and environmental analytes.

Magnetic Nanoparticles Coated with (R)-9-Acetoxystearic Acid for Biomedical Applications

The well-known ability to selectively drive nanomagnetic materials coated with anticancer drugs into tumor cells suggested the synthesis and the characterization of magnetic nanoparticles (MNPs) functionalized with (R)-9-acetoxystearic acid, the acetic ester of (R)-9-hydroxystearic acid (9-HSA), an antiproliferative agent active against different cancer cells. The acyl chloride of (R)-9-acetoxystearic acid, synthesized in two steps from 9-HSA, was reacted with (3-aminopropyl)triethoxysilane, chosen as a linker between MNPs and the stearyl moiety. In the last step, the novel amide was bound to magnetite NPs by reaction with silyl groups. A detailed structural, chemical, and magnetic characterization of the obtained material proved that it possesses properties in agreement with the requirements for drug delivery, opening the possibility to further insights focused on the 9-HSA biomedical applications.

Preparation and anti-Raji lymphoma efficacy of a novel pH sensitive and magnetic targeting nanoparticles drug delivery system

BACKGROUND

Non-Hodgkin's lymphoma (NHL) is a heterogeneous class of cancers that arises in lymph nodes or other lymphatic tissues, which causes many deaths worldwide and its incidence is increasing.

METHODS

In this study, a pH-responsive DMSA-Fe₃O₄ magnetic nanoparticles (MNPs) covalently connect with ADM and As₂O₃ as a drug delivery system was invented to discuss the anticancer efficacy in non-Hodgkin's lymphoma (NHL) cell line--Raji.

RESULTS

Detailedly, according to the chelation of ADM and Fe²⁺, the release rate of ADM was accelerated in acidic environment, and slowed down/blocked in neutral environment. The inhibitory effect to induce apoptosis of Fe₃O₄/As₂O₃+Doxil on Raji cells was obvious compared with that of single-drug group. Furthermore, the expression of Bcl-2 gene in Raji cells was suppressed under the action of MNPs.

CONCLUSION

Taken together, the novel pH-responsive MNPs was proven to be a promising synergistic form of magnetic targeted drugs for clinical treatment of human Raji lymphoma.

Doxorubicin/Cisplatin-Loaded Superparamagnetic Nanoparticles As A Stimuli-Responsive Co-Delivery System For Chemo-Photothermal Therapy

INTRODUCTION

To date, numerous iron-based nanostructures have been designed for cancer therapy applications. Although some of them were promising for clinical applications, few efforts have been made to maximize the therapeutic index of these carriers. Herein, PEGylated silica-coated iron oxide nanoparticles (PS-IONs) were introduced as multipurpose stimuli-responsive co-delivery nanocarriers for a combination of dual-drug chemotherapy and photothermal therapy.

METHODS

Superparamagnetic iron oxide nanoparticles were synthesized via the sonochemical method and coated by a thin layer of silica. The nanostructures were then further modified with a layer of di-carboxylate polyethylene glycol (6 kDa) and carboxylate-methoxy polyethylene glycol (6 kDa) to improve their stability, biocompatibility, and drug loading capability. Doxorubicin (DOX) and cisplatin (CDDP) were loaded on the PS-IONs through the interactions between the drug molecules and polyethylene glycol.

RESULTS

The PS-IONs demonstrated excellent cellular uptake, cytocompatibility, and hemocompatibility at the practical dosage. Furthermore, in addition to being an appropriate MRI agent, PS-IONs demonstrated superb photothermal property in 0.5 W/cm2 of 808 nm laser irradiation. The release of both drugs was effectively triggered by pH and NIR irradiation. As a result of the intracellular combination chemotherapy and 10 min of safe power laser irradiation, the highest cytotoxicity for iron-based nanocarriers (97.3±0.8%) was achieved.

CONCLUSION

The results of this study indicate the great potential of PS-IONs as a multifunctional targeted co-delivery system for cancer theranostic application and the advantage of employing proper combination therapy for cancer eradication.

Nanosized Fe3O4 an efficient PCR yield enhancer-Comparative study with Au, Ag nanoparticles

Nanomaterials-assisted PCR is a promising field of nanobiotechnology that amalgamates nanomaterials into the conventional PCR system to achieve better amplification of desired product. With literature documenting the variable effects of these nanomaterials on the PCR yield and amplification; it was thought worthwhile to compare the PCR enhancing efficiency of three transition metal nanoparticles in form of stable colloidal suspensions at varying concentrations.The nanoparticles(NPs) of silver, gold and magnetite were chemically synthesized by reducing their respective salts and characterized using UV-vis spectroscopy. Their morphology was assessed using nanoparticle tracking system and AFM. The effect of these nanofluids on amplification of 800 bp prokaryotic DNA template with 30% GC content was studied using conventional thermal cycler. The reaction kinetics for all the three nanofluids yielded a Gaussian curve of amplification with varying concentrations. The ammonium salt of oleic acid coated magnetite (Fe3O4) nanoparticles at a concentration of 0.72 × 10(-2)nM and average size of 33 nm demonstrated highest amplification efficiency of 190% as compared to the citrate stabilized AgNP-25 nm (45%) and AuNP-15.19 nm (134%) using a conventional PCR system. The major reasons that allow Fe3O4 NPs outperform the other 2 transition metal NP's seem to be attributed to its heat conduction property as well as effective adsorption of PCR components onto the ammonium salt of oleic acid coated magnetite nanofluids. The data from our study offers valuable information for the application of ferrofluids as economically, efficient and effective alternative for nanomaterial-assisted PCR yield enhancers.

Engineered Nanoparticles Against MDR in Cancer: The State of the Art and its Prospective

Cancer is a highly heterogeneous disease at intra/inter patient levels and known as the leading cause of death worldwide. A variety of mono and combinational therapies including chemotherapy have been evolved over the years for its effective treatment. However, advent of chemotherapeutic resistance or multidrug resistance (MDR) in cancer is a major challenge researchers are facing in cancer chemotherapy. MDR is a complex process having multifaceted non-cellular or cellular-based mechanisms. Research in the area of cancer nanotechnology over the past two decade has now proven that the smartly designed nanoparticles help in successful chemotherapy by overcoming the MDR and preferentially accumulate in the tumor region by means of active and passive targeting therefore reducing the offtarget accumulation of payload. Many of such nanoparticles are in different stages of clinical trials as nanomedicines showing promising result in cancer therapy including the resistant cases. Nanoparticles as chemotherapeutics carriers offer the opportunity to have multiple payload of drug and or imaging agents for combinational and theranostics therapy. Moreover, nanotechnology further bring in notice the new treatment strategies such as combining the NIR, MRI and HIFU in cancer chemotherapy and imaging. Here, we discussed the cellular/non-cellular factors constituting the MDR in cancer and the role of nanomedicines in effective chemotherapy of MDR cases of cancers. Moreover, recent advancements like combinational payload delivery and combined physical approach with nanotechnology in cancer therapy have also been discussed.

Understanding the binding interaction of imidazole with ZnO nanomaterials and clusters

The order of binding energy values for imidazole adsorbed ZnO clusters through the preferred azomethine nitrogen site is imidazole–Zn₄O₄ (R) > imidazole–Zn₃O₃ > imidazole–Zn₄O₄ (W) > imidazole–Zn₂O₂.

Thermodynamically feasible photoelectron transfer from bioactive π-expanded imidazole luminophores to ZnO nanocrystals

The chemical affinity between the nitrogen atom of the imidazole and the zinc ion on the surface of the nano oxide may be a reason for strong interaction of the ligand on nanoparticles causing the enhancement.

Distribution and accumulation of Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles in the tissues of ICR mice

Free Cy5.5 dye and Cy5.5-labeled thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) have been routinely used for in vivo optical imaging. However, there is little information about the distribution and accumulation of free Cy5.5 dye and Cy5.5-labeled TCL-SPION in the tissues of mice. Free Cy5.5 dye (0.1 mg/kg body weight) and Cy5.5-labeled TCL-SPION (15 mg/kg body weight) were intravenously injected into the tail vein of ICR mice. The biodistribution and accumulation of the TCL-SPION and Cy5.5 were observed by ex vivo optical imaging and fluorescence signal generation at various time points over 28 days. Cy5.5 dye fluorescence in various organs was rapidly eliminated from 0.5 to 24 h post-injection. Fluorescence intensity of Cy5.5 dye in the liver, lung, kidney, and stomach was fairly strong at the early time points within 1 day post-injection. Cy5.5-labeled TCL-SPION had the highest fluorescence density in the lung at 0.5 h post-injection and decreased rapidly over time. Fluorescence density in liver and spleen was maintained over 28 days. These results suggest that TCL-SPION can be useful as a carrier of therapeutic reagents to treat diseases by persisting for long periods of time in the body.

Nanodrug delivery in reversing multidrug resistance in cancer cells

Different mechanisms in cancer cells become resistant to one or more chemotherapeutics is known as multidrug resistance (MDR) which hinders chemotherapy efficacy. Potential factors for MDR includes enhanced drug detoxification, decreased drug uptake, increased intracellular nucleophiles levels, enhanced repair of drug induced DNA damage, overexpression of drug transporter such as P-glycoprotein(P-gp), multidrug resistance-associated proteins (MRP1, MRP2), and breast cancer resistance protein (BCRP). Currently nanoassemblies such as polymeric/solid lipid/inorganic/metal nanoparticles, quantum dots, dendrimers, liposomes, micelles has emerged as an innovative, effective, and promising platforms for treatment of drug resistant cancer cells. Nanocarriers have potential to improve drug therapeutic index, ability for multifunctionality, divert ABC-transporter mediated drug efflux mechanism and selective targeting to tumor cells, cancer stem cells, tumor initiating cells, or cancer microenvironment. Selective nanocarrier targeting to tumor overcomes dose-limiting side effects, lack of selectivity, tissue toxicity, limited drug access to tumor tissues, high drug doses, and emergence of multiple drug resistance with conventional or combination chemotherapy. Current review highlights various nanodrug delivery systems to overcome mechanism of MDR by neutralizing, evading, or exploiting the drug efflux pumps and those independent of drug efflux pump mechanism by silencing Bcl-2 and HIF1α gene expressions by siRNA and miRNA, modulating ceramide levels and targeting NF-κB. “Theragnostics” combining a cytotoxic agent, targeting moiety, chemosensitizing agent, and diagnostic imaging aid are highlighted as effective and innovative systems for tumor localization and overcoming MDR. Physical approaches such as combination of drug with thermal/ultrasound/photodynamic therapies to overcome MDR are focused. The review focuses on newer drug delivery systems developed to overcome MDR in cancer cell.

CdTe quantum dot as a fluorescence probe for vitamin B(12) in dosage form

We here report the CdTe quantum dot (CdTe QDs)-based sensor for probing vitamin B12 derivatives in aqueous solution. In this paper, simple and sensitive fluorescence quenching measurements has been employed. The Stern-Volmer constant (KSV), quenching rate constant (kq) and binding constant (K) were rationalized from fluorescence quenching measurement. Furthermore, the fluorescence resonance energy transfer (FRET) mechanism was discussed. This method was applicable over the concentration ranging from 1 to 14μg/mL (VB12) with correlation coefficient of 0.993. The limit of detection (LOD) of VB12 was found to be 0.15μg/mL. Moreover, the present approach opens a simple pathway for developing cost-effective, sensitive and selective QD-based fluorescence sensors/probes for biologically significant VB12 in pharmaceutical sample with mean recoveries in the range of 100-102.1%.

Photo-induced electric polarizability of Fe3O4 nanoparticles in weak optical fields

Using a developed co-precipitation method, we synthesized spherical Fe3O4 nanoparticles with a wide nonlinear absorption band of visible radiation. Optical properties of the synthesized nanoparticles dispersed in an optically transparent copolymer of methyl methacrylate with styrene were studied by optical spectroscopy and z-scan techniques. We found that the electric polarizability of Fe3O4 nanoparticles is altered by low-intensity visible radiation (I ≤ 0.2 kW/cm2; λ = 442 and 561 nm) and reaches a value of 107 Å3. The change in polarizability is induced by the intraband phototransition of charge carriers. This optical effect may be employed to improve the drug uptake properties of Fe3O4 nanoparticles. PACS: 33.15.Kr78.67.Bf42.70.Nq.

Anthracycline Nano-Delivery Systems to Overcome Multiple Drug Resistance: A Comprehensive Review

Anthracyclines (doxorubicin, daunorubicin, and idarubicin) are very effective chemotherapeutic drugs to treat many cancers; however, the development of multiple drug resistance (MDR) is one of the major limitations for their clinical applications. Nano-delivery systems have emerged as the novel cancer therapeutics to overcome MDR. Up until now, many anthracycline nano-delivery systems have been developed and reported to effectively circumvent MDR both in-vitro and in-vivo, and some of these systems have even advanced to clinical trials, such as the HPMA-doxorubicin (HPMA-DOX) conjugate. Doxil, a DOX PEGylated liposome formulation, was developed and approved by FDA in 1995. Unfortunately, this formulation does not address the MDR problem. In this comprehensive review, more than ten types of developed anthracycline nano-delivery systems to overcome MDR and their proposed mechanisms are covered and discussed, including liposomes; polymeric micelles, conjugate and nanoparticles; peptide/protein conjugates; solid-lipid, magnetic, gold, silica, and cyclodextrin nanoparticles; and carbon nanotubes.

Synergistic effect of a combination of nanoparticulate Fe3O4 and gambogic acid on phosphatidylinositol 3-kinase/Akt/Bad pathway of LOVO cells

Background:

The present study evaluated whether magnetic nanoparticles containing Fe₃O₄ could enhance the activity of gambogic acid in human colon cancer cells, and explored the potential mechanisms involved.

Methods:

Cytotoxicity was evaluated by MTT assay. The percentage of cells undergoing apoptosis was analyzed by flow cytometry, and cell morphology was observed under both an optical microscope and a fluorescence microscope. Reverse transcriptase polymerase chain reaction and Western blot assay were performed to determine the transcription of genes and expression of proteins, respectively.

Results:

Gambogic acid could inhibit proliferation of LOVO cells in a dose-dependent and time-dependent manner and induce apoptosis, which was dramatically enhanced by magnetic nanoparticles containing Fe₃O₄. The typical morphological features of apoptosis in LOVO cells were observed after treatment comprising gambogic acid with and without magnetic nanoparticles containing Fe₃O₄. Transcription of cytochrome c, caspase 9, and caspase 3 genes was higher in the group treated with magnetic nanoparticles containing Fe₃O₄ and gambogic acid than in the groups that received gambogic acid or magnetic nanoparticles containing Fe₃O₄, but transcription of phosphatidylinositol 3-kinase, Akt, and Bad genes decreased. Notably, expression of cytochrome c, caspase 9, and caspase 3 proteins in the group treated with gambogic acid and magnetic nanoparticles containing Fe₃O₄ was higher than in the groups receiving magnetic nanoparticles containing Fe₃O₄ or gambogic acid, while expression of p-PI3K, p-Akt, p-Bad, pro-caspase 9, and pro-caspase 3 degraded.

Conclusion:

Magnetic nanoparticles containing Fe₃O₄ can enhance apoptosis induced by gambogic acid which may be closely related to regulation of the PI3K/Akt/Bad pathway in the treatment of human colon cancer.

Prostate stem cell antigen-targeted nanoparticles with dual functional properties: in vivo imaging and cancer chemotherapy

Background:

We designed dual-functional nanoparticles for in vivo application using a modified electrostatic and covalent layer-by-layer assembly strategy to address the challenge of assessment and treatment of hormone-refractory prostate cancer.

Methods:

Core-shell nanoparticles were formulated by integrating three distinct functional components, ie, a core constituted by poly(D,L-lactic-co-glycolic acid), docetaxel, and hydrophobic superparamagnetic iron oxide nanocrystals (SPIONs), a multilayer shell formed by poly(allylamine hydrochloride) and two different sized poly(ethylene glycol) molecules, and a single-chain prostate stem cell antigen antibody conjugated to the nanoparticle surface for targeted delivery.

Results:

Drug release profiles indicated that the dual-function nanoparticles had a sustained release pattern over 764 hours, and SPIONs could facilitate the controlled release of the drug in vitro. The nanoparticles showed increased antitumor efficiency and enhanced magnetic resonance imaging in vitro through targeted delivery of docetaxel and SPIONs to PC3M cells. Moreover, in nude mice bearing PC3M xenografts, the nanoparticles provided MRI negative contrast enhancement, as well as halting and even reversing tumor growth during the 76-day study duration, and without significant systemic toxicity. The lifespan of the mice treated with these targeted dual-function nanoparticles was significantly increased (Chi-square = 22.514, P < 0.0001).

Conclusion:

This dual-function nanomedical platform may be a promising candidate for tumor imaging and targeted delivery of chemotherapeutic agents in vivo.

Copolymer nanoparticles composed of sulfobetaine and poly(ε-caprolactone) as novel anticancer drug carriers

Novel ABA type amphiphilic copolymers (PCL-APS-PCL) consisting of polycaprolactone (PCL) (A) as hydrophobic block and N,N'-bis (2-hydroxyethyl) methylamine ammonium propane sulfonate (APS) (B) as hydrophilic segment, self-assembled into nanoparticles (NPs) with solvent evaporation method. The sizes and size distributions of NPs were characterized by dynamic light scattering. The morphology of NPs was observed by scanning electron microscopy (SEM). The critical micelle concentration (CMC) was determined by fluorescent probe. The drug loading content (DLC) and the drug release amount were characterized by UV-visible spectrophotometer. The cytotoxicity of the NPs was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazoliumbromide (MTT) assay. It was found that the NPs were spherical in shape with sizes around 100 nm. The CMCs of the copolymers were quite low (×10(-4) mg/mL). The DLC decreased with lengthening of hydrophobic PCL block. In vitro drug release experiment demonstrated that the release rate of paclitaxel sped with the decrease of PCL length. MTT results showed that NPs were nontoxic to osteoblast and human epithelial carcinoma (hela) cells. After drug loading, NPs could restrain the growth of hela or even kill hela cells. Therefore, these preliminary studies suggest that the novel PCL-APS-PCL NPs have a great potential application as anticancer drug-delivery carriers.

Mesoporous silica nanoparticles loading doxorubicin reverse multidrug resistance: performance and mechanism

Multidrug resistance (MDR) is one of the major obstacles for successful chemotherapy in cancer. One of the effective approaches to overcome MDR is to use nanoparticle-mediated drug delivery to increase drug accumulation in drug resistant cancer cells. In this work, we first report that the performance and mechanism of an inorganic engineered delivery system based on mesoporous silica nanoparticles (MSNs) loading doxorubicin (DMNs) to overcome the MDR of MCF-7/ADR (a DOX-resistant and P-glycoprotein (P-gp) over-expression cancer cell line). The experimental results showed that DMNs could enhance the cellular uptake of doxorubicin (DOX) and increase the cell proliferation suppression effect of DOX against MCF-7/ADR cells. The IC(50) of DMNs against MCF-7/ADR cells was 8-fold lower than that of free DOX. However, an improved effect of DOX in DMNs against MCF-7 cells (a DOX-sensitive cancer cell line) was not found. The increased cellular uptake and nuclear accumulation of DOX delivered by DMNs in MCF-7/ADR cells was confirmed by confocal laser scanning microscopy, and could result from the down-regulation of P-gp and bypassing the efflux action by MSNs themselves. The cellular uptake mechanism of DMNs indicated that the macropinocytosis was one of the pathways for the uptake of DMNs by MCF-7/ADR cells. The in vivo biodistribution showed that DMNs induced a higher accumulation of DOX in drug resistant tumors than free DOX. These results suggested that MSNs could be an effective delivery system to overcome multidrug resistance.

Prevention of acute graft-versus-host disease by magnetic nanoparticles of Fe₃O₄ combined with cyclosporin A in murine models

Objective

To investigate the effect of magnetic nanoparticles (MNPs) of Fe₃O₄ combined with cyclosporin A (CsA) on acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in murine models.

Methods

BALB/c mice preconditioned with total-body irradiation generated aGVHD and then were followed with allo-HSCT from allogeneic C57BL/6. Recipient mice were randomly divided into five groups and then given different supportive care and followed up. The physical signs and median survival time (MST) were recorded, peripheral blood cell counts were assessed, and histological changes of the main tissues were evaluated with hematoxylin-eosin staining. Furthermore, fluorescence polarization immunoassay was used to monitor the concentration of CsA.

Results

The irradiated-only mice developed typical aGVHD, and the typical signs of aGVHD in the skin, liver, and intestine were observed by histopathological examination. Both CsA alone and in combination with Fe₃O₄ MNPs significantly prolonged the MST of recipient mice compared with both the control and the Fe₃O₄ MNPs groups. Notably, a combination of CsA with Fe₃O₄ MNPs can elevate the peripheral white blood cells and alleviate the symptoms of GVHD and the pathological damage after allo-HSCT. In addition, the concentration of CsA was higher in plasma, heart, liver, and spleen of recipient mice with supporting care of the combination of CsA with Fe₃O₄ MNPs than with CsA alone.

Conclusion

Taken together, Fe₃O₄ MNPs may be used as a carrier of immunosuppressive agents to alleviate GVHD after allo-HSCT in murine models.

Effect of magnetic Fe3O4 nanoparticles with 2-methoxyestradiol on the cell-cycle progression and apoptosis of myelodysplastic syndrome cells

This study aims to evaluate the potential benefit of combination therapy of 2-methoxyestradiol (2ME) and magnetic nanoparticles of Fe₃O₄ (MNPs-Fe₃O₄) on myelodysplastic syndrome (MDS) SKM-1 cells and its underlying mechanisms. The effect of the unique properties of tetraheptylammonium-capped MNPs-Fe₃O₄ with 2ME on cytotoxicity was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell-cycle distribution and apoptosis were assessed by flow cytometry. The expression of cell-cycle marker protein was measured by Western blotting. Growth inhibition rate of SKM-1 cells treated with the 2ME-loaded MNPs-Fe₃O₄ was enhanced when compared with 2ME alone. 2ME led to an increase of caspase-3 expression, followed by apoptosis, which was significantly increased when combined with an MNPs-Fe₃O₄ carrier. Moreover, the copolymer of 2ME with MNPs- Fe₃O₄ blocked a nearly two-fold increase in SKM-1 cells located in G₂/M phase than in 2ME alone, which may be associated with an accompanying increase of p21 as well as a decrease in cyclin B1 and cdc2 expression, but there was no obvious difference between the MNPs-Fe₃O₄ and control group. These findings suggest that the unique properties of MNPs-Fe₃O₄ as a carrier for 2ME, a new anticancer agent currently in clinical trials, may be a logical strategy to enhance the therapeutic activity of MDS.

Inorganic-organic hybrid nanomaterials for therapeutic and diagnostic imaging applications

Nanotechnology offers outstanding potential for future biomedical applications. In particular, due to their unique characteristics, hybrid nanomaterials have recently been investigated as promising platforms for imaging and therapeutic applications. This class of nanoparticles can not only retain valuable features of both inorganic and organic moieties, but also provides the ability to systematically modify the properties of the hybrid material through the combination of functional elements. Moreover, the conjugation of targeting moieties on the surface of these nanomaterials gives them specific targeted imaging and therapeutic properties. In this review, we summarize the recent reports in the synthesis of hybrid nanomaterials and their applications in biomedical areas. Their applications as imaging and therapeutic agents in vivo will be highlighted.

Effect of interaction of magnetic nanoparticles of Fe₃O₄ and artesunate on apoptosis of K562 cells

The present study evaluated whether the magnetic nanoparticles of Fe₃O₄ (MNPs-Fe₃O₄) could enhance the activity of artesunate (ART), and to explore its potential mechanisms. Cytotoxicity of the copolymer of ART with MNPs-Fe₃O₄ on K562 cells was detected by MTT assay and the apoptosis rate of K562 cells was measured by flow cytometry. Protein expression levels of bcl-2, bax, bcl-rambo, caspase-3, and survivin in K562 cells were measured by Western blot. After being incubated with the copolymer of ART with MNPs-Fe₃O₄ for 48 hours, the growth inhibition rate of K562 cells was significantly increased compared with that of K562 cells treated with ART alone (P < 0.05), and the apoptosis rate of K562 cells was increased significantly compared with that of K562 cells treated with ART alone, suggesting that MNPs-Fe₃O₄ can enhance the activity of ART. Interestingly, the copolymer-induced cell death was attenuated by caspase inhibitor Z-VAD-FMK. Our results also showed that treatment with the copolymer of MNPs-Fe₃O₄ and ART increased the expression of bcl-2, bax, bcl-rambo, and caspase-3 proteins, and decreased the expression of survivin protein in K562 cells compared with ART treatment alone. These results suggest that MNPs-Fe₃O₄ can enhance ART-induced apoptosis, which may be related to the upregulation of bcl-rambo and downregulation of survivin.

Nanomedicine for targeted cancer therapy: towards the overcoming of drug resistance

Anticancer drug resistance almost invariably emerges and poses major obstacles towards curative therapy of various human malignancies. In the current review we will distinguish between mechanisms of chemoresistance that are predominantly mediated by ATP-driven multidrug resistance (MDR) efflux transporters, typically of the ATP-binding cassette (ABC) superfamily, and those that are independent of such drug efflux pumps. In recent years, multiple nanoparticle (NP)-based therapeutic systems have been developed that were rationally designed to overcome drug resistance by neutralizing, evading or exploiting various drug efflux pumps and other resistance mechanisms. NPs are being exploited for selective drug delivery to tumor cells, to cancer stem/tumor initiating cells and/or to the supportive cancer cell microenvironment, i.e. stroma or tumor vasculature. Some of these NPs are currently undergoing preclinical in vivo studies as well as advanced stages of clinical evaluation with promising results. Nanovehicles harboring a payload of therapeutic drug combinations for the selective targeting and elimination of tumor cells as well as the simultaneous overcoming of mechanisms of drug resistance are a subject of intense research efforts, some of which are expected to enter clinical trials in the near future. In the present review we highlight novel approaches to selectively target cancer cells and overcome drug resistance phenomena, through the use of various nanometric drug delivery systems. In the near future, it is anticipated that innovative theragnostic nanovehicles will be developed which will harbor four major components: (1) a selective targeting moiety, (2) a diagnostic imaging aid for the localization of the malignant tumor and its micro- or macrometastases, (3) a cytotoxic, small molecule drug(s) or novel therapeutic biological(s), and (4) a chemosensitizing agent aimed at neutralizing a resistance mechanism, or exploiting a molecular "Achilles hill" of drug resistant cells. We propose to name these envisioned four element-containing nanovehicle platform, "quadrugnostic" nanomedicine. This targeted strategy holds promise in paving the way for the introduction of highly effective nanoscopic vehicles for cancer therapeutics while overcoming drug resistance.

Doxorubicin loaded iron oxide nanoparticles overcome multidrug resistance in cancer in vitro

Multidrug resistance (MDR) is characterized by the overexpression of ATP-binding cassette (ABC) transporters that actively pump a broad class of hydrophobic chemotherapeutic drugs out of cancer cells. MDR is a major mechanism of treatment resistance in a variety of human tumors, and clinically applicable strategies to circumvent MDR remain to be characterized. Here we describe the fabrication and characterization of a drug-loaded iron oxide nanoparticle designed to circumvent MDR. Doxorubicin (DOX), an anthracycline antibiotic commonly used in cancer chemotherapy and substrate for ABC-mediated drug efflux, was covalently bound to polyethylenimine via a pH sensitive hydrazone linkage and conjugated to an iron oxide nanoparticle coated with amine terminated polyethylene glycol. Drug loading, physiochemical properties and pH lability of the DOX-hydrazone linkage were evaluated in vitro. Nanoparticle uptake, retention, and dose-dependent effects on viability were compared in wild-type and DOX-resistant ABC transporter over-expressing rat glioma C6 cells. We found that DOX release from nanoparticles was greatest at acidic pH, indicative of cleavage of the hydrazone linkage. DOX-conjugated nanoparticles were readily taken up by wild-type and drug-resistant cells. In contrast to free drug, DOX-conjugated nanoparticles persisted in drug-resistant cells, indicating that they were not subject to drug efflux. Greater retention of DOX-conjugated nanoparticles was accompanied by reduction of viability relative to cells treated with free drug. Our results suggest that DOX-conjugated nanoparticles could improve the efficacy of chemotherapy by circumventing MDR.

Reversal of multidrug resistance by magnetic Fe3O4 nanoparticle copolymerizating daunorubicin and MDR1 shRNA expression vector in leukemia cells

In many instances, multidrug resistance (MDR) is mediated by increasing the expression at the cell surface of the MDR1 gene product, P-glycoprotein (P-gp), a 170-kD energy-dependent efflux pump. The aim of this study was to investigate the potential benefit of combination therapy with magnetic Fe₃O₄ nanoparticle [MNP (Fe₃O₄)] and MDR1 shRNA expression vector in K562/A02 cells. For stable reversal of “classical” MDR by short hairpin RNA (shRNA) aiming directly at the target sequence (3491–3509, 1539–1557, and 3103–3121 nucleotide) of MDR1 mRNA. PGC silencer-U6-neo-GFP-shRNA/MDR1 called PGY1–1, PGY1–2, and PGY1–3 were constructed and transfected into K562/A02 cells by lipofectamine 2000. After transfected and incubated with or without MNP (Fe₃O₄) for 48 hours, the transcription of MDR1 mRNA and the expression of P-gp were detected by quantitative real-time PCR and Western-blot assay respectively. Meanwhile intracellular concentration of DNR in K562/A02 cells was detected by flow cytometry (FCM). PGC silencer-U6-neo-GFP-shRNA/MDR1 was successfully constructed, which was confirmed by sequencing and PGY1–2 had the greatest MDR1 gene inhibitory ratio. Analysis of the reversal ratio of MDR, the concentration of daunorubicin (DNR) and the transcription of MDR1 gene and expression of P-gp in K562/A02 showed that combination of DNR with either MNP (Fe₃O₄) or PGY1–2 exerted a potent cytotoxic effect on K562/A02 cells, while combination of MNP (Fe₃O₄) and PGY1–2 could synergistically reverse multidrug resistance. Thus our in vitro data strongly suggested that a combination of MNP (Fe₃O₄) and shRNA expression vector might be a more sufficient and less toxic anti-MDR method on leukemia.

Daunorubicin-loaded magnetic nanoparticles of Fe3O4 overcome multidrug resistance and induce apoptosis of K562-n/VCR cells in vivo

Multidrug resistance (MDR) is a major obstacle to cancer chemotherapy. We evaluated the effect of daunorubicin (DNR)-loaded magnetic nanoparticles of Fe₃O₄ (MNPs-Fe₃O₄) on K562-n/VCR cells in vivo. K562-n and its MDR counterpart K562-n/VCR cell were inoculated into nude mice subcutaneously. The mice were randomly divided into four groups: group A received normal saline, group B received DNR, group C received MNPs-Fe₃O₄, and group D received DNR-loaded MNPs-Fe₃O₄. For K562-n/VCR tumor, the weight was markedly lower in group D than that in groups A, B, and C. The transcriptions of Mdr-1 and Bcl-2 gene were significantly lower in group D than those in groups A, B, and C. The expression of Bcl-2 was lower in group D than those in groups A, B, and C, but there was no difference in the expression of P-glycoprotein. The transcriptions and expressions of Bax and caspase-3 in group D were increased significantly when compared with groups A, B, and C. In conclusion, DNR-loaded MNPs-Fe₃O₄ can overcome MDR in vivo.

Pulmonary toxicity and kinetic study of Cy5.5-conjugated superparamagnetic iron oxide nanoparticles by optical imaging

Recent advances in the development of nanotechnology and devices now make it possible to accurately deliver drugs or genes to the lung. Magnetic nanoparticles can be used as contrast agents, thermal therapy for cancer, and be made to concentrate to target sites through an external magnetic field. However, these advantages may also become problematic when taking into account safety and toxicological factors. This study demonstrated the pulmonary toxicity and kinetic profile of anti-biofouling polymer coated, Cy5.5-conjugated thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) by optical imaging. Negatively charged, 36 nm-sized, Cy5.5-conjugated TCL-SPION was prepared for optical imaging probe. Cy5.5-conjugated TCL-SPION was intratracheally instilled into the lung by a non-surgical method. Cy5.5-conjugated TCL-SPION slightly induced pulmonary inflammation. The instilled nanoparticles were distributed mainly in the lung and excreted in the urine via glomerular filtration. Urinary excretion was peaked at 3 h after instillation. No toxicity was found under the concentration of 1.8 mg/kg and the half-lives of nanoparticles in the lung and urine were estimated to be about 14.4+/-0.54 h and 24.7+/-1.02 h, respectively. Although further studies are required, our results showed that Cy5.5-conjugated TCL-SPION can be a good candidate for use in pulmonary delivery vehicles and diagnostic probes.

Polysaccharide surface modified Fe3O4 nanoparticles for camptothecin loading and release

Fe(3)O(4) nanoparticles were stabilized using different functional polysaccharides, such as chitosan (CS), O-carboxymethylchitosan (OCMCS) and (N-succinyl-O-carboxymethylchitosan (NSOCMCS) to improve their bioactivity. The release profile and the in vitro cancer cell inhibition activity of camptothecin (CPT) loaded polysaccharide modified Fe(3)O(4) nanoparticles were systematically studies. The particle size and size distribution of CPT-loaded polysaccharide modified Fe(3)O(4) nanoparticles were found to be strongly dependent on polysaccharide character. Such polysaccharide character could also affect CPT adsorption efficiency, CPT release behavior and bovine serum albumin (BSA) unspecific binding capacity. After 24 h incubation of 7721 cancer cells with CPT-loaded polysaccharide modified Fe(3)O(4) nanoparticles, significant changes in cell morphology could be discernible from phase contrast microscopy. Cytotoxicity assay showed these polysaccharide modified Fe(3)O(4) nanoparticles did not exhibit noteworthy cytotoxicity against 7721, however, the in vitro inhibition rate of CPT-loaded polysaccharide modified Fe(3)O(4) nanoparticles against 7721 liver cancer cell increased significantly in comparison with that of CPT-free drug.

Reversal of multidrug resistance by magnetic Fe3O4 nanoparticle copolymerizating daunorubicin and 5-bromotetrandrine in xenograft nude-mice

In this paper we establish the xenograft leukemia model with stable multidrug resistance in nude mice and to investigate the reversal effect of 5-bromotetrandrine (5-BrTet) and magnetic nanoparticle of Fe₃O₄ (MNP-Fe₃O₄) combined with daunorubicin (DNR) in vivo. Two subclones of K562 and K562/A02 cells were inoculated subcutaneously into the back of athymic nude mice (1 × 10⁷ cells/each) respectively to establish leukemia xenograft models. Drug-resistant and sensitive tumor-bearing nude mice were assigned randomly into five groups which were treated with normal saline; DNR; NP-Fe₃O₄ combined with DNR; 5-BrTet combined with DNR; 5-BrTet and MNP-Fe₃O₄ combined with DNR, respectively. The incidence of formation, growth characteristics, weight, and volume of tumors were observed. The histopathologic examination of tumors and organs were detected. For resistant tumors, the protein levels of Bcl-2, and BAX were detected by Western blot. Bcl-2, BAX, and caspase-3 genes were also detected. For K562/A02 cells xenograft tumors, 5-BrTet and MNP-Fe₃O₄ combined with DNR significantly suppressed growth of tumor. A histopathologic examination of tumors clearly showed necrosis of the tumors. Application of 5-BrTet and MNP-Fe₃O₄ inhibited the expression of Bcl-2 protein and upregulated the expression of BAX and caspase-3 proteins in K562/A02 cells xenograft tumor. It is concluded that 5-BrTet and MNP-Fe₃O₄ combined with DNR had a significant tumor-suppressing effect on a MDR leukemia cells xenograft model.