Functionalized magnetic nanoparticles for the detection and quantitative analysis of cell surface antigen

Advances in antibody nanoconjugates for diagnosis and therapy: A review of recent studies and trends

Nowadays, the targeted imaging probe and drug delivery systems are the novel breakthrough area in the nanomedicine and treatment of various diseases. Conjugation of monoclonal antibodies and their fragments on nanoparticles (NPs) have a remarkable impact on personalized medicine, such that it provides specific internalization and accumulation in the tumor microenvironment. Targeted imaging and early detection of cancer is presumably the strong participant to a diminution in mortality and recurrence of cancer disease that will be the next generation of the imaging device in clinical application. These intelligent delivery systems can deliver therapeutic agents that target cancerous tissue with minimal side effects and a wide therapeutic window. Overall, the linkage between the antibody and NPs is a critical subject and requires precise design and development. The attachment of antibody nanoconjugates (Ab-NCs) on the antigen surface shouldn't affect the function of the antibody-antigen binding. Also, the stability of the antibody nanoconjugates in blood circulation is concerned to avoid the release of drug in non-targeted regions and the possible for specific toxicity while disposal to the desired site. Here, we update the recent progress of Ab-NCs to improve early detection and cancer therapy.

Synthesis and Cytotoxicity Assessment of Gold-coated Magnetic Iron Oxide Nanoparticles

INTRODUCTION

One class of magnetic nanoparticles is magnetic iron oxide nanoparticles (MIONs) which has been widely offered due to of their many advantages. Owing to the extensive application of MIONs in biomedicine, before they can be used in vivo, their cytotoxicity have to be investigated. Therefore, there is an urgent need for understanding the potential risks associated with MIONs.

MATERIALS AND METHODS

Firstly, gold-coated Fe₃O₄ nanoparticles (GMNP) were synthesized. The size, structure and spectroscopic properties of the nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffractometry (XRD) and UV-Visible spectrophotometer, respectively. Cytotoxicity of nanoparticles was studied with different concentrations ranging from 10 µg/mL up to 400 µg/mL and for different incubation times (12 hours and 24 hours) on MCF-7 and HFFF-PI6. Cytotoxicity study was performed by MTT assay.

RESULTS

XRD pattern confirmed the structure of GMNPs and TEM image shows that GMNPs are under 50 nm. For MCF-7 and HFFF-PI6 cells, at concentration of 300 and 400 µg/mL, Fe₃O₄ nanoparticles are toxic, respectively. Moreover, for both cells, cell viability for GMNPs is higher than %80, therefore, up to 400 µg/mL they are not toxic. Results show that for both cells, Fe₃O₄ nanoparticles have higher cytotoxicity than GMNPs.

CONCLUSION

This finding suggests that gold coating reduces the toxic effects of uncoated Fe₃O₄ nanoparticles. Less toxicity of GMNP may be attributed to controlled release from Fe²⁺ ions in intracellular space. Moreover, cell toxicity increased with raise in dose (concentration) and incubation time.

In vitro Study of SPIONs-C595 as Molecular Imaging Probe for Specific Breast Cancer (MCF-7) Cells Detection

Background

Magnetic resonance imaging (MRI) plays an essential role in molecular imaging by delivering the contrast agent into targeted cancer cells. The aim of this study was to evaluate the C595 monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles (SPIONs-C595) for the detection of breast cancer cell (MCF-7).

Methods

The conjugation of monoclonal antibody and nanoparticles was confirmed using X-ray diffraction, transmission electron microscopy, and photon correlation spectroscopy. The selectivity of the nanoprobe for breast cancer cells (MCF-7) was obtained by Prussian blue, atomic emission spectroscopy, and MRI relaxometry.

Results

The in vitro MRI showed that T2 relaxation time will be reduced 76% when using T2-weighed magnetic resonance images compared to the control group (untreated cells) at the dose of 200 μg Fe/ml, as the optimum dose. In addition, the results showed the high uptake of nanoprobe into MCF-7 cancer cells.

Conclusion

The SPIONs-C595 nanoprobe has potential for the detection of specific breast cancer.

Magnetic Iron Oxide Nanoparticles as T2 MR Imaging Contrast Agent for Detection of Breast Cancer (MCF-7) Cell

BACKGROUND

Advances of nanotechnology have led to the development of nano-materials with both potential diagnostic and therapeutic applications. Among them, Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) have received particular attention. Modified EDC coupling fraction was used to fabricate the SPION-C595 as an MR imaging contrast agent for breast cancer detection in early stages.

METHODS

Nanoprobe characterization was confirmed using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDAX), and Photon Correlation Spectroscopy (PCS). Protein and iron concentration of nanoprobe was examined by standard method. MTT assay was performed to evaluate the cytotoxicity of the nanoprobe in breast cancer cell line (MCF-7). T₂-weighted MR imaging was performed to evaluate the signal enhancement on T₂ relaxation time of nanoprobe using spin-echo pulse sequence.

RESULTS

As results showed, SPIONs-C595 provided active targeting of breast cancer cell (MCF-7) at a final concentration of 600 μgFe/ml. The final concentration of protein was calculated to be at 0.78 μgprotein/ml. The hydrodynamic size of the nanoprobe was 87.4±0.7 nm. The MR imaging results showed a good reduction of T₂ relaxation rates for the highest dose of SPIONs-C595.

DISCUSSION

Based on the results, SPIONs-C595 nanoprobe has a potential in T₂-weighted MR imaging contrast agent for breast cancer cell (MCF-7) detection.

In Vitro Evaluation of Gd(3+)-Anionic Linear Globular Dendrimer-Monoclonal Antibody: Potential Magnetic Resonance Imaging Contrast Agents for Prostate Cancer Cell Imaging

PURPOSE

Early stage prostate cancer diagnosis is of high global interest. Magnetic resonance imaging (MRI) is a non-invasive modality for early cancer diagnosis, in particular for prostate cancer detection. The research aim is to synthesize a nanodendrimer and its conjugate with C595 monoclonal antibody (mAb C595), against prostate cancer, followed by its chelating with Gd(3+).

PROCEDURES

Anti-MUC-1 mAb C595 was conjugated to an anionic linear globular dendrimer (ALGDG2). The polyethylene glycol core and citric acid shell were synthesized followed by loading with Gd(3+) to make novel contrast agents for functional MRI. The in vitro behavior and MRI parameters of the nanoconjugate were investigated performing several studies such as cell toxicity and TNF-alpha evaluations. The investigation of magnetic resonance imaging parameters indicated how well nanoconjugate performs in (1)H-NMR and (17)O-NMR in vitro.

RESULTS

Results showed a potential specific MRI activity by improving the swelling responses cell binding. The MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide) assay demonstrated that this contrast agent had significant cytotoxicity on prostate cancer cells.

CONCLUSIONS

These results showed that Gd(3+)-ALGDG2-C595 is a potential prostate molecular imaging agent and could be considered as an ideal functional nanoprobe. Additionally, further investigations by clinical trials are in the pipeline.

Versatile theranostics agents designed by coating ferrite nanoparticles with biocompatible polymers

Three biocompatible polymers, polyethylene glycol (PEG), dextran and chitosan, have been used in this work to control the colloidal stability of magnetic nanoparticles (14 ± 5 nm in diameter) and to vary the aggregation state in order to study their effect on relaxometric and heating properties. Two different coating strategies have been deeply developed; one based on the formation of an amide bond between citric acid coated nanoparticles (NPs) and amine groups present on the polymer surface and the other based on the NP encapsulation. Relaxometric properties revealed that proton relaxation rates strongly depend on the coating layer hydrophilicity and the aggregation state of the particles due to the presence of magnetic interactions. Thus, while PEG coating reduces particle aggregation by increasing inter-particle spacing leading to reduction of both T1 and T2 relaxation, dextran and chitosan lead to an increase mainly in T2 values due to the aggregation of particles in bigger clusters where they are in close contact. Dextran and chitosan coated NPs have also shown a remarkable heating effect during the application of an alternating magnetic field. They have proved to be potential candidates as theranostic agents for cancer diagnosis and treatment. Finally, cytotoxicity of PEG conjugated NPs, which seem to be ideal for intravenous administration because of their small hydrodynamic size, was investigated resulting in high cell viability even at 0.2 mg Fe ml(-1) after 24 h of incubation. This suspension can be used as drug/biomolecule carrier for in vivo applications.

Aptamer-conjugated Magnetic Nanoparticles as Targeted Magnetic Resonance Imaging Contrast Agent for Breast Cancer

Early detection of breast cancer is the most effective way to improve the survival rate in women. Magnetic resonance imaging (MRI) offers high spatial resolution and good anatomic details, and its lower sensitivity can be improved by using targeted molecular imaging. In this study, AS1411 aptamer was conjugated to Fe₃O₄@Au nanoparticles for specific targeting of mouse mammary carcinoma (4T1) cells that overexpress nucleolin. In vitro cytotoxicity of aptamer-conjugated nanoparticles was assessed on 4T1 and HFFF-PI6 (control) cells. The ability of the synthesized nanoprobe to target specifically the nucleolin overexpressed cells was assessed with the MRI technique. Results show that the synthesized nanoprobe produced strongly darkened T₂-weighted magnetic resonance (MR) images with 4T1 cells, whereas the MR images of HFFF-PI6 cells incubated with the nanoprobe are brighter, showing small changes compared to water. The results demonstrate that in a Fe concentration of 45 μg/mL, the nanoprobe reduced by 90% MR image intensity in 4T1 cells compared with the 27% reduction in HFFF-PI6 cells. Analysis of MR signal intensity showed statistically significant signal intensity difference between 4T1 and HFFF-PI6 cells treated with the nanoprobe. MRI experiments demonstrate the high potential of the synthesized nanoprobe as a specific MRI contrast agent for detection of nucleolin-expressing breast cancer cells.

Multiple MTS Assay as the Alternative Method to Determine Survival Fraction of the Irradiated HT-29 Colon Cancer Cells

A multiple colorimetric assay has been introduced to evaluate the proliferation and determination of survival fraction (SF) of irradiated cells. The estimation of SF based on the cell-growth curve information is the major advantage of this assay. In this study, the utility of multiple-MTS assay for the SF estimation of irradiated HT-29 colon cancer cells, which were plated before irradiation, was evaluated. The SF of HT-29 colon cancer cells under irradiation with 9 MV photon was estimated using multiple-MTS assay and colony assay. Finally, the correlation between two assays was evaluated. Results showed that there are no significant differences between the SF obtained by two assays at different radiation doses (P > 0.05), and the survival curves have quite similar trends. In conclusion, multiple MTS-assay can be a reliable method to determine the SF of irradiated colon cancer cells that plated before irradiation.

Monoclonal antibody conjugated magnetic nanoparticles could target MUC-1-positive cells in vitro but not in vivo

MUC1 antigen is recognized as a high-molecular-weight glycoprotein that is unexpectedly over-expressed in human breast and other carcinomas. In contrast, C595 a monoclonal antibody (mAb) against the protein core of the human urinary epithelial machine, is commonly expressed in breast carcinomas. The aim of this study was to conjugate ultra-small super paramagnetic iron oxide nanoparticles (USPIO) with C595 mAb, in order to detect in vivo MUC1 expression. A dual contrast agent (the C595 antibody-conjugated USPIO labeled with 99mTc) was prepared for targeted imaging and therapy of anti-MUC1-expressing cancers. The C595 antibody-conjugated USPIO had good stability and reactivity in the presence of blood plasma at 37 °C. No significant differences were observed in immunoreactivity results between conjugated and nonconjugated nanoparticles. The T1 and T2 measurements show >79 and 29% increments (for 0.02 mg/ml iron concentrations) in T1 and T2 values for USPIO-C595 in comparison with USPIO, respectively. The nanoprobes showed the interesting targeting capability of finding the MUC1-positive cell line in vitro. However, we found disappointing in vivo results (i.e. very low accumulation of nanoprobes in the targeted site while >80% of the injected dose per gram was taken up by the liver and spleen), not only due to the coverage of targeting site by protein corona but also because of absorption of opsonin-based proteins at the surface of nanoprobes.

Modeling the efficiency of a magnetic needle for collecting magnetic cells

As new magnetic nanoparticle-based technologies are developed and new target cells are identified, there is a critical need to understand the features important for magnetic isolation of specific cells in fluids, an increasingly important tool in disease research and diagnosis. To investigate magnetic cell collection, cell-sized spherical microparticles, coated with superparamagnetic nanoparticles, were suspended in (1) glycerine-water solutions, chosen to approximate the range of viscosities of bone marrow, and (2) water in which 3, 5, 10 and 100% of the total suspended microspheres are coated with magnetic nanoparticles, to model collection of rare magnetic nanoparticle-coated cells from a mixture of cells in a fluid. The magnetic microspheres were collected on a magnetic needle, and we demonstrate that the collection efficiency versus time can be modeled using a simple, heuristically-derived function, with three physically-significant parameters. The function enables experimentally-obtained collection efficiencies to be scaled to extract the effective drag of the suspending medium. The results of this analysis demonstrate that the effective drag scales linearly with fluid viscosity, as expected. Surprisingly, increasing the number of non-magnetic microspheres in the suspending fluid results increases the collection of magnetic microspheres, corresponding to a decrease in the effective drag of the medium.

Superparamagnetic iron oxide-C595: Potential MR imaging contrast agents for ovarian cancer detection

Superparamagnetic iron oxide nanoparticles (SPIONs), have played an important role in the promotion of image contrast in magnetic resonance imaging modality. The objective of present study is describing SPIONs conjugated with C595 monoclonal antibody (mAb) against MUC1-expressing ovarian cancer (OVCAR3) cell. Magnetic resonance imaging parameters of the prepared nanoconjugate was investigated in vitro: characterization, cell toxicity, flow cytometry, Prussian blue staining, and cellular uptake as well as biodistribution and magnetic resonance signal intensities under in vivo conditions were also investigated. Magnetic resonance imaging and biodistribution results showed good tumor accumulation and detection, no cytotoxicity, and potential selective as anti-ovarian cancer. In conclusion, based on the findings SPIONs-C595 nanosized-probe is potentially, a selective ovarian molecular imaging tool. Further subsequent in vivo studies and clinical trials are warranted.

MR imaging and targeting of a specific alveolar macrophage subpopulation in LPS-induced COPD animal model using antibody-conjugated magnetic nanoparticles

Purpose

Targeting and noninvasive imaging of a specific alveolar macrophage subpopulation in the lung has revealed the importance for early and better diagnosis and therapy of chronic obstructive pulmonary disease (COPD). In this study, the in vivo effect of pulmonary administration of iron oxide nanoparticles on the polarization profile of macrophages was assessed, and a noninvasive free-breathing magnetic resonance imaging (MRI) protocol coupled with the use of biocompatible antibody-conjugated superparamagnetic iron oxide (SPIO) nanoparticles was developed to enable specific targeting and imaging of a particular macrophage subpopulation in lipopolysaccharide-induced COPD mice model.

Materials and methods

Enzyme-linked immunosorbent assay, Real-time polymerase chain reaction, and flow cytometry analysis were performed to assess the biocompatibility of PEGylated dextran-coated SPIO nanoparticles. Specific biomarkers for M1 and M2 macrophages subsets were selected for conjugation with magnetic nanoparticles. MRI protocol using ultra-short echo time sequence was optimized to enable simultaneous detection of inflammation progress in the lung and detection of macrophages subsets. Flow cytometry and immunohistochemistry analysis were finally performed to confirm MRI readouts and to characterize the polarization profile of targeted macrophages.

Results

The tested SPIO nanoparticles, under the current experimental conditions, were found to be biocompatible for lung administration in preclinical settings. Cluster of differentiation (CD)86- and CD206-conjugated magnetic nanoparticles enabled successful noninvasive detection of M1 and M2 macrophage subpopulations, respectively, and were found to co-localize with inflammatory regions induced by lipopolysaccharide challenge. No variation in the polarization profile of targeted macrophages was observed, even though a continuum switch in their polarization might occur. However, further confirmatory studies are required to conclusively establish this observation.

Conclusion

Coupling of magnetic iron oxide nanoparticles with a specific antibody targeted to a particular macrophage subpopulation could offer a promising strategy for an early and better diagnosis of pulmonary inflammatory diseases using noninvasive MRI.

Detection of MUC1-expressing ovarian cancer by C595 monoclonal antibody-conjugated SPIONs using MR imaging

The aim of this study is to find out the development and application of MUC1-expressing ovarian cancer (OVCAR3) by C595 monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles (SPIONs) using MR imaging. At the end, its use as a nanosized contrast agent MR imaging probe for ovarian cancer detection was investigated. The strategy is to use SPIONs attached to C595 mAb that binds to the MUC1, to specifically detect ovarian cancer cells. Anticancer effects and MR imaging parameters of the prepared nanoconjugate was investigated both under in vitro and in vivo experiments. The characterization of nanoconjugate includes its size, cell toxicity, flow cytometry, Prussian blue staining test and its cellular uptake as well as its biodistribution, and MR imaging was also investigated. The findings of the study showed good tumor accumulation and detection, no in vivo toxicity, and potential selective antiovarian cancer activity. Overall, based on the findings SPIONs-C595 nanosized probe is a selective ovarian molecular imaging modality. Further subsequent clinical trials appear warranted.

HTCC-modified nanoclay for tissue engineering applications: a synergistic cell growth and antibacterial efficiency

This paper deals with the synthesis of a biocompatible chitosan ammonium salt N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) and using it in montmorillonite ion-exchange process. HTCC-modified montmorillonite (Mt) with different chemical ratios was successfully synthesized, and their characteristics have been verified by XRD and FTIR analyses. Produced samples have been evaluated in terms of antibacterial efficiency and biocompatibility (cell culture test). Antibacterial efficiency of synthesized HTCC/Mt samples has been confirmed against both gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). The results disclosed that the antibacterial efficiency of HTCC-modified montmorillonite was unexpectedly even more than HTCC. This excellent synergistic effect has been referred to entrapping bacteria between the intercalated structures of HTCC-modified montmorillonite. Then HTCC on clay layers can seriously attack and damage the entrapped bacteria. An extraordinary biocompatibility, cell attachment, and cell growth even more than tissue culture polystyrene (TCPS) have been recorded in the case of this novel kind of modified clay. Due to existing concerns about serious and chronic infections after implant placement, this natural-based bioactive and antibacterial modified clay can be used in electrospun nanofibers and other polymeric implants with promising mechanical properties for tissue engineering applications.