Synthesis of bombesin-functionalized iron oxide nanoparticles and their specific uptake in prostate cancer cells

The imaging of molecular markers associated with disease offers the possibility for earlier detection and improved treatment monitoring. Receptors for gastrin-releasing peptide are overexpressed on prostate cancer cells offering a promising imaging target, and analogs of bombesin, an amphibian tetradecapeptide have been previously demonstrated to target these receptors. Therefore, the pan-bombesin analog [β-Ala11, Phe13, Nle14]bombesin-(7–14) was conjugated through a linker to dye-functionalized superparamagnetic iron oxide nanoparticles for the development of a new potential magnetic resonance imaging probe. The peptide was conjugated via click chemistry, demonstrating a complementary alternative methodology to conventional peptide-nanoparticle conjugation strategies. The peptide-functionalized nanoparticles were then demonstrated to be selectively taken up by PC-3 prostate cancer cells relative to unfunctionalized nanoparticles and this uptake was inhibited by the presence of free peptide, confirming the specificity of the interaction. This study suggests that these nanoparticles have the potential to serve as magnetic resonance imaging probes for the detection of prostate cancer.     

Multifunctional iron platinum stealth immunomicelles: targeted detection of human prostate cancer cells using both fluorescence and magnetic resonance imaging

Superparamagnetic iron oxide nanoparticles (SPIONs) are the most common type of contrast agents used in contrast agent-enhanced magnetic resonance imaging (MRI). Still, there is a great deal of room for improvement, and nanoparticles with increased MRI relaxivities are needed to increase the contrast enhancement in MRI applied to various medical conditions including cancer. We report the synthesis of superparamagnetic iron platinum nanoparticles (SIPPs) and subsequent encapsulation using PEGylated phospholipids to create stealth immunomicelles (DSPE-SIPPs) that can be specifically targeted to human prostate cancer cell lines and detected using both MRI and fluorescence imaging. SIPP cores and DSPE-SIPPs were 8.5 ± 1.6 nm and 42.9 ± 8.2 nm in diameter, respectively, and the SIPPs had a magnetic moment of 120 A m²/kg iron. J591, a monoclonal antibody against prostate specific membrane antigen (PSMA), was conjugated to the DSPE-SIPPs (J591-DSPE-SIPPs), and specific targeting of J591-DSPE-SIPPs to PSMA-expressing human prostate cancer cell lines was demonstrated using fluorescence confocal microscopy. The transverse relaxivity of the DSPE-SIPPs, measured at 4.7 Tesla, was 300.6 ± 8.5 s^?1 mM^?1, which is 13-fold better than commercially available SPIONs (23.8 ± 6.9 s^?1 mM^?1) and ~3-fold better than reported relaxivities for Feridex^® and Resovist^®. Our data suggest that J591-DSPE-SIPPs specifically target human prostate cancer cells in vitro, are superior contrast agents in T ₂-weighted MRI, and can be detected using fluorescence imaging. To our knowledge, this is the first report on the synthesis of multifunctional SIPP micelles and using SIPPs for the specific detection of prostate cancer.     

Biochemical and biomedical applications of multifunctional magnetic nanoparticles: a review

Nanotechnology offers tremendous potential for future medical diagnosis and therapy. Various types of nanoparticles have been extensively studied for numerous biochemical and biomedical applications. Magnetic nanoparticles are well-established nanomaterials that offer controlled size, ability to be manipulated by an external magnetic field, and enhancement of contrast in magnetic resonance imaging. As a result, these nanoparticles could have many applications including bacterial detection, protein purification, enzyme immobilization, contamination decorporation, drug delivery, hyperthermia, etc. All these biochemical and biomedical applications require that these nanoparticles should satisfy some prerequisites including high magnetization, good stability, biocompatibility, and biodegradability. Because of the potential benefits of multimodal functionality in biomedical applications, in this account highlights some general strategies to generate magnetic nanoparticle-based multifunctional nanostructures. After these magnetic nanoparticles are conjugated with proper ligands (e.g., nitrilotriacetate), polymers (e.g., polyacrylic acid, chitosan, temperature- and pH-sensitive polymers), antibodies, enzymes, and inorganic metals (e.g., gold), such biofunctional magnetic nanoparticles exhibit many advantages in biomedical applications. In addition, the multifunctional magnetic nanoparticles have been widely applied in biochemical fields including enzyme immobilization and protein purification.     

Synthesis of amino-group functionalized superparamagnetic iron oxide nanoparticles and applications as biomedical labeling probes

Superparamagnetic iron oxide (SPIO) nanoparticles were synthesized by coprecipitation technique and further functionalized with amino-group to obtain amino-group functionalized (amino-SPIO) nanoparticles. The X-ray diffraction results reveal the structure of amino-SPIO nanoparticles, from which the average iron core diameter is approximately 10 nm by calculation; while Zetasizer reveals their hydrodynamic diameter are mainly distributed in the range of 40?C60 nm. These nanoparticles can be taken up by liver tissue, resulting in dramatically darkening of liver tissue under T2-magnetic resonance imaging (MRI). The spin?Cspin relaxivity coefficient of these nanoparticles is 179.20 mM^?1 s^?1 in a 1.5 T magnetic resonance system. In addition, amino-SPIO nanoparticles were conjugated to Tat (FITC) peptide and incubated with neural stem cells in vitro, the authors can detect the positive-labeling (labeled) neural stem cells showing green fluorescence, which indicates Tat (FITC) peptide-derivated amino-SPIO nanoparticles are able to enter cells. Furthermore, it was also find significant negative T2 contrast enhancement when compared with the non-nanoparticles-labeled neural stem cells in T2-weighted MRI. The amino-SPIO nanoparticles show promising potential as a new type of labeling probes, which can be used in magnetic resonance-enhanced imaging and fluorescence diagnosis.     

Synthesis and bio-applications of targeted magnetic-fluorescent composite nanoparticles

Magnetic-fluorescent nanoparticles have a tremendous potential in biology. As the benefits of these materials gained recognition, increasing attention has been given to the conjugation of magnetic-fluorescent nanoparticles with targeting ligands. The magnetic and fluorescent properties of nanoparticles offer several functionalities, including imaging, separation, and visualization, while the presence of a targeting ligand allows for selective cell and tissue targeting. In this review, methods for the synthesis of targeted magnetic-fluorescent nanoparticles are explored, and recent applications of these nanocomposites to the detection and separation of biomolecules, fluorescent and magnetic resonance imaging, and cancer diagnosis and treatment will be summarized. As these materials are further optimized, targeted magnetic-fluorescent nanoparticles hold great promise for the diagnosis and treatment of some diseases.     

Nanosized cancer cell-targeted polymeric immunomicelles loaded with superparamagnetic iron oxide nanoparticles

Stable 30–50 nm polymeric polyethylene glycol–phosphatidylethanolamine (PEG–PE)-based micelles entrapping superparamagnetic iron oxide nanoparticles (SPION) have been prepared. At similar concentrations of SPION, the SPION-micelles had significantly better magnetic resonance imaging (MRI) T2 relaxation signal compared to ‘plain’ SPION. Freeze-fracture electron microscopy confirmed SPION entrapment in the lipid core of the PEG–PE micelles. To enhance the targeting capability of these micelles, their surface was modified with the cancer cell-specific anti-nucleosome monoclonal antibody 2C5 (mAb 2C5). Such mAb 2C5-SPION immunomicelles demonstrated specific binding with cancer cells in vitro and were able to bring more SPION to the cancer cells thus demonstrating the potential to be used as targeted MRI contrast agents for tumor imaging.     

Theranostic Iron@Gold Core–Shell Nanoparticles for Simultaneous Hyperthermia‐Chemotherapy upon Photo‐Stimulation

The challenges of nanoparticles, such as size‐dependent toxicity, nonbiocompatibility, or inability to undergo functionalization for drug conjugation, limit their biomedical application in more than one domain. Oval‐shaped iron@gold core–shell (oFe@Au) magnetic nanoparticles are engineered and their applications in magnetic resonance imaging (MRI), optical coherence tomography (OCT), and controlled drug release, are explored via photo stimulation‐generated hyperthermia. The oFe@Au nanoparticles have a size of 42.57 ± 5.99 nm and consist of 10.76 and 89.24 atomic % of Fe and Au, respectively. Upon photo‐stimulation for 10 and 15 minutes, the levels of cancer cell death induced by methotrexate‐conjugated oFe@Au nanoparticles are sixfold and fourfold higher, respectively, than oFe@Au nanoparticles alone. MRI and OCT confirm the application of these nanoparticles as a contrast agent. Finally, results of in vivo experiments reveal that the temperature is elevated by 13.2 °C, when oFe@Au nanoparticles are irradiated with a 167 mW cm^?2 808 nm laser, which results in a significant reduction in tumor volume and scab formation after 7 days, followed by complete disappearance after 14 days. The ability of these nanoparticles to generate heat upon photo‐stimulation also opens new doors for studying hyperthermia‐mediated controlled drug release for cancer therapy. Applications include biomedical engineering, cancer therapy, and theranostics fields.     

Synthesis,characterization, and in vitro biological evaluation of highly stable diversely functionalized superparamagnetic iron oxide nanoparticles

In this article, we report the design and synthesis of a series of well-dispersed superparamagnetic iron oxide nanoparticles (SPIONs) using chitosan as a surface modifying agent to develop a potential T ₂ contrast probe for magnetic resonance imaging (MRI). The amine, carboxyl, hydroxyl, and thiol functionalities were introduced on chitosan-coated magnetic probe via simple reactions with small reactive organic molecules to afford a series of biofunctionalized nanoparticles. Physico-chemical characterizations of these functionalized nanoparticles were performed by TEM, XRD, DLS, FTIR, and VSM. The colloidal stability of these functionalized iron oxide nanoparticles was investigated in presence of phosphate buffer saline, high salt concentrations and different cell media for 1 week. MRI analysis of human cervical carcinoma (HeLa) cell lines treated with nanoparticles elucidated that the amine-functionalized nanoparticles exhibited higher amount of signal darkening and lower T ₂ relaxation in comparison to the others. The cellular internalization efficacy of these functionalized SPIONs was also investigated with HeLa cancer cell line by magnetically activated cell sorting (MACS) and fluorescence microscopy and results established selectively higher internalization efficacy of amine-functionalized nanoparticles to cancer cells. These positive attributes demonstrated that these nanoconjugates can be used as a promising platform for further in vitro and in vivo biological evaluations.     

Effects of surfactants on properties of polymer-coated magnetic nanoparticles for drug delivery application

The objective of this research was to compare the effects of two different surfactants on the physicochemical properties of thermo-responsive poly(N-isopropylacrylamide-acrylamide-allylamine) (PNIPAAm-AAm-AH)-coated magnetic nanoparticles (MNPs). Sodium dodecyl sulfate (SDS) as a commonly used surfactant in nanoparticle formulation process and Pluronic F127 as an FDA approved material were used as surfactants to synthesize PNIPAAm-AAm-AH-coated MNPs (PMNPs). The properties of PMNPs synthesized using SDS (PMNPs-SDS) and PF127 (PMNPs-PF127) were compared in terms of size, polydispersity, surface charge, drug loading efficiency, drug release profile, biocompatibility, cellular uptake, and ligand conjugation efficiency. These nanoparticles had a stable core–shell structure with about a 100-nm diameter and were superparamagnetic in behavior with no difference in the magnetic properties in both types of nanoparticles. In vitro cell studies showed that PMNPs-PF127 were more cytocompatible and taken up more by prostate cancer cells than that of PMNPs-SDS. Cells internalized with these nanoparticles generated a dark negative contrast in agarose phantoms for magnetic resonance imaging. Furthermore, a higher doxorubicin release at 40 °C was observed from PMNPs-PF127, and the released drugs were pharmacologically active in killing cancer cells. Finally, surfactant type did not affect the conjugation efficiency to the nanoparticles when folic acid was used as a targeting ligand model. These results indicate that PF127 might be a better surfactant to form polymer-coated magnetic nanoparticles for targeted and controlled drug delivery.     

Aptamer-modified gold nanoparticles for targeting breast cancer cells through light scattering

In this study, we demonstrated the potential use of nucleic acid ligand (aptamers) conjugated gold nanoparticles (AuNPs) for cancer cell detection. Through specific binding of the aptamers toward platelet-derived growth factor (PDGF), MDA-MB-231 and Hs578T cells (cancer cells) that over-express PDGF, interact with Apt-AuNPs to a greater extent than do H184B5F5/M10 cells (normal cells). These results were confirmed through inductively coupled plasma mass spectrometry measurements of the gold ion concentrations within these cells. Aggregation of the Apt-AuNPs in the cytoplasm of the cancer cells led to the generation of an intense scattered light upon photo-illumination; this phenomenon allows the differentiation of cancer cells from normal cells using a dark field optical microscope. The presence of Apt-AuNPs suppressed the proliferation of MDA-MB-231 cancer cells, but not H184B5F5/M10 cells.     

In Vivo Targeted Cancer Theranostics by Core/Shell‐Structured Multifunctional Prussian Blue/PLGA “Nanococktails”

The construction of high‐performance nanotheranostic agent with Food and Drug Administration (FDA)‐approved materials for efficient treatment of breast cancer is still of great challenge. This work reports, for the first time, on the elaborate integration of two FDA‐approved materials together to construct a multifunctional core/shell‐structured “nanococktail” for cancer theranostics. The biocompatible Prussian blue nanoparticles with high photothermal‐conversion performance are coated by poly(lactic‐co‐glycolic acid) followed by further surface targeting engineering (folic acid conjugation). The anticancer drug paclitaxel is concurrently encapsulated into the nanocarrier with high efficiency and capacity. Especially, these “nanococktails” act as the desirable contrast agents for photoacoustic/magnetic resonance imaging dual‐mode diagnostic imaging, providing the potential for guidance and monitoring during the therapeutic process, which has been systematically demonstrated both in vitro and in vivo. Importantly, these “nanococktails” have demonstrated their high performance in synergistic in vivo photothermal therapy and chemotherapy against breast cancer tumor xenograft. This work not only provides a high‐performance theranostic “nanococktail” platform for efficient theranostic treatment of cancer but also paves a new way for the integration of various functional moieties together for realizing the specific diagnostic imaging‐guided and synergistic cancer therapy.     

Synthesis of Hexagonal ZnO-PQ7 Nano Disks Conjugated with Folic Acid to Image MCF – 7 Cancer Cells

Surface modified ZnO nanomaterial is widely used in the field of bioimaging worldwide due to its optical properties, electronic characteristics and biocompatibility. Fluorescent enhanced, Polyquaternium-7(PQ7) capped, ZnO hexagonal nano disks (ZnO-PQ7) were synthesised by simple wet chemical method. The structural and optical properties of ZnO-PQ7 hexagonal nano disks were characterized using XRD, UV-Visible, Fluorescence, HRTEM, EDAX and FTIR studies. The size of synthesised ZnO-PQ7 were around 30-45 nm as confirmed by HRTEM studies. Fluorescence emission intensity increased with increase in PQ7 concentration. ZnO-PQ7 was further conjugated with folic acid (FA) to target human breast cancer cell line (MCF-7) via EDC/NHS coupling chemistry. Conjugation of folic acid with ZnO-PQ7 was confirmed by FTIR studies. The cell viability study using Methyl thiazolyltetrazolium(MTT) assay has demonstrated that the ZnO-PQ7 conjugated FA composites (ZnO-PQ7-FA) exhibit low toxicity towards MCF-7 up to a concentration of 125 μg/mL. Confocal laser scanning microscopic images confirmed the uptake of ZnO-PQ7-FA nanoparticles by MCF-7 cells. This study reveals ZnO-PQ7-FA nano disks as a potential imaging agent for detection of cancer cells. The synthesis route reported in this article is simple and easy to follow for the synthesis of ZnO-PQ7-FA in bulk quantities with high purity.     

GoldMag nanoparticles with core/shell structure: characterization and application in MR molecular imaging

GoldMag is a kind of bi-functional nanoparticle, composed of a gold nanoshell and an iron oxide core. GoldMag combines the antibody immobilization property of gold nanoshell with the superparamagnetic feature of the iron oxide core. Rabbit anti-mouse IgG was immobilized on the surface of GoldMag to synthesize GoldMag-IgG in a single-step process. Transmission electron microscopy, UV/Vis spectrophotometry, zeta potential analysis, dynamic light scattering, enzyme-linked immunosorbent assay, and magnetic resonance imaging (MRI) were employed to characterize the nanostructures and the spectroscopic and magnetic properties of GoldMag and GoldMag-IgG. The antibody encapsulation efficiency of GoldMag was measured as 58.7%, and the antibody loading capacity was 88 μg IgG per milligram of GoldMag. The immunoactivity of GoldMag-IgG was estimated to be 43.3% of that of the original IgG. The cytotoxicity of GoldMag was assessed by MTT assay, which showed that it has only little influence on human dermal lymphatic endothelial cells. MR imaging of different concentrations of ultrasmall superparamagnetic iron oxide, GoldMag, and GoldMag-IgG showed that 3 μg/mL of nanoparticles could significantly affect the MRI signal intensity of GRE T2*WI. The results demonstrate that GoldMag nanoparticles can be effectively conjugated with biomacromolecules and possess great potential for MR molecular imaging.     

Preparation of epidermal growth factor (EGF) conjugated iron oxide nanoparticles and their internalization into colon cancer cells

Epidermal growth factor (EGF) was conjugated with carboxymethyldextran (CMDx) coated iron oxide magnetic nanoparticles using carbodiimide chemistry to obtain magnetic nanoparticles that target the epidermal growth factor receptor (EGFR). Epidermal growth factor modified magnetic nanoparticles were colloidally stable when suspended in biological buffers such as PBS and cell culture media. Both targeted and non-targeted nanoparticles were incubated with CaCo-2 cancer cells, known to overexpress EGFR. Nanoparticle localization within the cell was visualized by confocal laser scanning microscopy and light microscopy using Prussian blue stain. Results showed that targeted magnetic nanoparticles were rapidly accumulated in both flask-shaped small vesicles and large circular endocytic structures. Internalization patterns suggest that both clathrin-dependent and clathrin-independent receptors mediated endocytosis mechanisms are responsible for nanoparticle internalization.     

基于级联卷积神经网络的前列腺磁共振图像分类

针对深度学习训练成本高,以及基于磁共振图像的前列腺癌临床诊断需要大量医学常识且极为耗时的问题,本文提出了一种基于级联卷积神经网络（Convolutional Neural Network,CNN）和磁共振图像的前列腺癌（Prostate Cancer,PCa）自动分类诊断方法,该网络以Faster-RCNN作为前网络,对前列腺区域进行提取分割,用于排除前列腺附近组织器官的干扰;以基于ResNet改进的网络结构CNN40_bottleneck作为后网络,用于对前列腺区域病变进行分类.后网络由瓶颈结构串联组成,其中使用批量标准化（Batch Normalization,BN）、全局平均池化（Global Average Pooling,GAP）进行优化.实验结果证明,本文方法对前列腺癌诊断结果较好,而且缩减了训练时间和参数量,有效降低了训练成本.     

A novel magnetic fluid based on starch-coated magnetite nanoparticles functionalized with homing peptide

Preparation and characterization in vitro and in vivo of a novel magnetic fluid based on starch-coated magnetite nanoparticles functionalized with homing peptide is reported in this paper. Precursory magnetic fluids stabilized with starch were prepared, in a polymeric starch matrix, by controlled chemical coprecipitation of magnetite phase from aqueous solutions. The average hydrodynamic diameter of starch-coated iron oxide nanoparticles (SIONs) was 46 nm. As a homing peptide, A54 is the most effective peptide specific to the human hepatocellular carcinoma cell line BEL-7402. Final magnetic fluids were obtained through chemical coupling of homing peptide labeled with 5-carboxyl-fluorescein (FAM-A54) and SIONs. Magnetic measurements showed the saturation magnetization value of SIONs amounted to 45 emu/g and the FAM-A54-coupled SIONs showed a good magnetic response in magnetic field. The results of experiments in vitro and in vivo showed that SIONs were endowed with specific affinity to corresponding tumor cells after coupling with FAM-A54 and the FAM-A54-coupled SIONs could be accumulated in the tumor tissue with more efficiency than individual magnetic targeting or biomolecular targeting. This novel magnetic fluid with dual function has great potential applications in diagnostics and therapeutics of human tumor such as drug targeting, magnetic hyperthermia, and magnetic resonance imaging.     

Prostate cancer: comparison of pre-operative 0.35 T MRI with whole-mount histopathology.

Magnetic resonance imaging of the prostate was performed in eight patients prior to radical prostatectomy. The results of the imaging studies were then directly compared to histopathologic findings from whole-mount histologic sections. Magnetic resonance imaging identified 82% of cancers greater than 5 mm in minimal diameter. Cancers were identified as areas of decreased signal intensity compared to the high signal intensity peripheral zone on long TR/TE sequences. Cancers were best detected when they involved the middle level of the gland and the posterior half of the prostate. Of the individual tumors identified by imaging, the amount of tumor involvement was underestimated by 37% and overestimated by 22% by MRI. We conclude that magnetic resonance imaging can identify prostate cancer, but has limitations as a screening modality and in accurately assessing the amount of involvement of the prostate gland by cancer.     

Antibody immobilization on gold nanoparticles coated layer-by-layer with polyelectrolytes

Nanoscale materials are used in the biomedical field for magnetic resonance imaging, protein detection and drug/gene delivery. Gold nanoparticles (AuNPs) are particularly investigated in cancer treatment and imaging. In this study, we described a simple and reliable liquid method to coat AuNPs (diameter: 21 nm) layer-by-layer with alternative cationic polyallylamine and anionic polystyrenesulfonate. The C-terminal amino acid of the antibody directed against anti-bovine serum albumin was activated by EDC/NHS, and then condensed with the amino functions of the external polyallylamine layer. An ELISA test confirmed that the antigen recognition of the bioconjugate antibody was conserved. This AuNP coating and the covalently coupling could be used as a generic process for binding other specific antibodies, particularly those overexpressed in cancer cells and angiogenesis.     

Multifunctional nanoparticle platforms for in vivo MRI enhancement and photodynamic therapy of a rat brain cancer

A paradigm for brain cancer detection, treatment, and monitoring is established. Multifunctional biomedical nanoparticles (30–60 nm) containing photosensitizer externally deliver reactive oxygen species (ROS) to cancer cells while simultaneously enhancing magnetic resonance imaging (MRI) contrast providing real-time tumor kill measurement. Plasma residence time control and specific cell targeting are achieved. A 5 min treatment in rats halted and even reversed in vivo tumor growth after 3–4 days post-treatment.     

Emerging spectroscopic techniques for prostate cancer diagnosis

ABSTRACT

Over the past several decades, large efforts have been made to diagnose and overcome prostate cancer. Among all screening methods, the measurement of prostate-specific antigen (PSA) threshold has been stood out and contributed to diagnose prostate cancer (PCa) in a large number of men. Nevertheless, the early detection of prostate carcinoma and its focal imaging is remaining crucial to diminish the elevated number of PCa-related deaths. Because of the multifocal behavior of PCa development, a whole gland ablation has been practiced during previous years. Furthermore, there is an evidence of the likelihood of high-risk PCa that proves once again the importance of early diagnosis and accurate staging of the disease. So far, numerous advanced spectroscopic methods with different approaches have been reported as the alternative tools to conventional techniques of PCa diagnosis and imaging. In this review, we introduce innovative emerging techniques utilizing spectroscopic methods such as photoluminescence, surface-enhanced Raman spectroscopy, and surface plasmon resonance to measure the ultralow level of PSA. In addition, we review novel and alternative approaches of diagnosis such as imaging methods through photoluminescence, magnetic resonance imaging, and positron emission tomography.