Therapeutic Efficiency of Multiple Applications of Magnetic Hyperthermia Technique in Glioblastoma Using Aminosilane Coated Iron Oxide Nanoparticles: In Vitro and In Vivo Study

Magnetic hyperthermia (MHT) has been shown as a promising alternative therapy for glioblastoma (GBM) treatment. This study consists of three parts: The first part evaluates the heating potential of aminosilane-coated superparamagnetic iron oxide nanoparticles (SPIONa). The second and third parts comprise the evaluation of MHT multiple applications in GBM model, either in vitro or in vivo. The obtained heating curves of SPIONa (100 nm, +20 mV) and their specific absorption rates (SAR) stablished the best therapeutic conditions for frequencies (309 kHz and 557 kHz) and magnetic field (300 Gauss), which were stablished based on three in vitro MHT application in C6 GBM cell line. The bioluminescence (BLI) signal decayed in all applications and parameters tested and 309 kHz with 300 Gauss have shown to provide the best therapeutic effect. These parameters were also established for three MHT applications in vivo, in which the decay of BLI signal correlates with reduced tumor and also with decreased tumor glucose uptake assessed by positron emission tomography (PET) images. The behavior assessment showed a slight improvement after each MHT therapy, but after three applications the motor function displayed a relevant and progressive improvement until the latest evaluation. Thus, MHT multiple applications allowed an almost total regression of the GBM tumor in vivo. However, futher evaluations after the therapy acute phase are necessary to follow the evolution or tumor total regression. BLI, positron emission tomography (PET), and spontaneous locomotion evaluation techniques were effective in longitudinally monitoring the therapeutic effects of the MHT technique.

Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance

Superparamagnetic iron oxide nanoparticles (SPION) are extensively used for magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), as well as for magnetic fluid hyperthermia (MFH). We here describe a sequential centrifugation protocol to obtain SPION with well-defined sizes from a polydisperse SPION starting formulation, synthesized using the routinely employed co-precipitation technique. Transmission electron microscopy, dynamic light scattering and nanoparticle tracking analyses show that the SPION fractions obtained upon size-isolation are well-defined and almost monodisperse. MRI, MPI and MFH analyses demonstrate improved imaging and hyperthermia performance for size-isolated SPION as compared to the polydisperse starting mixture, as well as to commercial and clinically used iron oxide nanoparticle formulations, such as Resovist® and Sinerem®. The size-isolation protocol presented here may help to identify SPION with optimal properties for diagnostic, therapeutic and theranostic applications.

Influence of Magnetic Micelles on Assembly and Deposition of Porphyrin J-Aggregates

Clusters of superparamagnetic iron oxide nanoparticles (SPIONs) have been incorporated into the hydrophobic core of polyethylene glycol (PEG)-modified phospholipid micelles. Two different PEG-phospholipids have been selected to guarantee water solubility and provide an external corona, bearing neutral (SPIONs@PEG-micelles) or positively charged amino groups (SPIONs@NH2-PEG-micelles). Under acidic conditions and with specific mixing protocols (porphyrin first, PF, or porphyrin last, PL), the water-soluble 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin (TPPS) forms chiral J-aggregates, and in the presence of the two different types of magnetic micelles, an increase of the aggregation rates has been generally observed. In the case of the neutral SPIONs@PEG-micelles, PL protocol affords a stable nanosystem, whereas PF protocol is effective with the charged SPIONs@NH2-PEG-micelles. In both cases, chiral J-aggregates embedded into the magnetic micelles (TPPS@SPIONs@micelles) have been characterized in solution through UV/vis absorption and circular/linear dichroism. An external magnetic field allows depositing films of the TPPS@SPIONs@micelles that retain their chiroptical properties and exhibit a high degree of alignment, which is also confirmed by atomic force microscopy.

Toxicity of superparamagnetic iron oxide nanoparticles to the microalga Chlamydomonas reinhardtii

Superparamagnetic iron oxide nanoparticles (SPION) have been widely studied for different biomedical and environmental applications. In this study we evaluated the toxicity and potential alterations of relevant physiological parameters caused to the microalga Chlamydomonas reinhardtii (C. reinhardtii) upon exposure to SPION. The results showed dose-dependent toxicity. A mechanistic study combining flow cytometry and physiological endpoints showed a toxic response consisting of a decrease in metabolic activity, increased oxidative stress and alterations in the mitochondrial membrane potential. Additionally, and due to the light absorption of SPION suspensions, we observed a significant shading effect, causing a marked decrease in photosynthetic activity. In this work, we demonstrated for the first time, the internalization of SPION by endocytosis in C. reinhardtii. These results demonstrated that SPION pose a potential risk for the environment if not managed properly.

Accuracy of Magnetometer-Guided Sentinel Lymphadenectomy after Intraprostatic Injection of Superparamagnetic Iron Oxide Nanoparticles in Prostate Cancer: The SentiMag Pro II Study

Radioisotope-guided sentinel lymph node dissection (sLND) has shown high diagnostic reliability in prostate (PCa) and other cancers. To overcome the limitations of the radioactive tracers, magnetometer-guided sLND using superparamagnetic iron oxide nanoparticles (SPIONs) has been successfully used in PCa. This prospective study (SentiMag Pro II, DRKS00007671) determined the diagnostic accuracy of magnetometer-guided sLND in intermediate- and high-risk PCa. Fifty intermediate- or high-risk PCa patients (prostate-specific antigen (PSA) ≥ 10 ng/mL and/or Gleason score ≥ 7; median PSA 10.8 ng/mL, IQR 7.4–19.2 ng/mL) were enrolled. After the intraprostatic SPIONs injection a day earlier, patients underwent magnetometer-guided sLND and extended lymph node dissection (eLND, followed by radical prostatectomy. SLNs were detected in in vivo and in ex vivo samples. Diagnostic accuracy of sLND was assessed using eLND as the reference. SLNs were detected in all patients (detection rate 100%), with 447 sentinel lymph nodes SLNs (median 9, IQR 6–12) being identified and 966 LNs (median 18, IQR 15–23) being removed. Thirty-six percent (18/50) of patients had LN metastases (median 2, IQR 1–3). Magnetometer-guided sLND had 100% sensitivity, 97.0% specificity, 94.4% positive predictive value, 100% negative predictive value, 0.0% false negative rate, and 3.0% additional diagnostic value (LN metastases only in SLNs outside the eLND template). In vivo, one positive SLN/LN-positive patient was missed, resulting in a sensitivity of 94.4%. In conclusion, this new magnetic sentinel procedure has high accuracy for nodal staging in intermediate- and high-risk PCa. The reliability of intraoperative SLN detection using this magnetometer system requires verification in further multicentric studies.

Incorporation of SPION-casein core-shells into silk-fibroin nanofibers for cardiac tissue engineering

Mimicking the structure of extracellular matrix (ECM) of myocardium is necessary for fabrication of functional cardiac tissue. The superparamagnetic iron oxide nanoparticles (SPIONs, Fe₃ O₄ ), as new generation of magnetic nanoparticles (NPs), are highly intended in biomedical studies. Here, SPION NPs (1 wt%) were synthesized and incorporated into silk-fibroin (SF) electrospun nanofibers to enhance mechanical properties and topography of the scaffolds. Then, the mouse embryonic cardiac cells (ECCs) were seeded on the scaffolds for in vitro studies. The SPION NPs were studied by scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM). SF nanofibers were characterized after incorporation of SPIONs by SEM, TEM, water contact angle measurement, and tensile test. Furthermore, cytocompatibility of scaffolds was confirmed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. SEM images showed that ECCs attached to the scaffolds with elongated morphologies. Also, the real-time PCR and immunostaining studies approved upregulation of cardiac functional genes in ECCs seeded on the SF/SPION-casein scaffolds including GATA-4, cardiac troponin T, Nkx 2.5, and alpha-myosin heavy chain, compared with the ones in SF. In conclusion, incorporation of core-shells in SF supports cardiac differentiation, while has no negative impact on ECCs' proliferation and self-renewal capacity.

Co-encapsulation of superparamagnetic nanoparticles and doxorubicin in PLGA nanocarriers: Development, characterization and in vitro antitumor efficacy in glioma cells

With a very poor prognosis and no clear etiology, glioma is the most aggressive cancer in the brain. Thanks to its versatility, nanomedicine is a promising option to overcome the limitations on chemotherapy imposed by the blood brain barrier (BBB). The objective of this paper was to obtain monitored tumor-targeted therapeutic nanoparticles (NPs). To that end, theranostic surfactant-coated polymer poly-Lactic-co-Glycolic Acid (PLGA) nanoplatform encapsulating doxorubicin hydrochloride (DOX) and superparamagnetic iron oxide NPs (SPIONs) were developed. Different non-ionic surfactants known as BBB crossing enhancers (Tween 80, Brij-35, Pluronic F68 or Vitamin E-TPGS) were used to develop 4 types of theranostic nanoplatforms, which were characterized in terms of size and morphology by DLS, TEM and STEM-HAADF analyses. Moreover, the 3-month stability test, the therapeutic efficacy against different glioma cell lines (U87-MG, 9L/LacZ and patient derived-neuronal stem cells) and the Magnetic Resonance Imaging (MRI) relaxivity were studied. Results showed that the synthesised nanoplatforms were stable at 4 °C after their lyophilization, being that of paramount importance to ensure a long-term stability in a future in vivo application. Furthermore, the theranostic nanoplatforms were efficient in the in vitro treatment of glioma cells, proving to have imaging efficacy as MRI contrast agents. Our results show an efficient loading of drugs and good value of the relaxivity. Therefore, the efficient theranostic hybrid nanoplatform developed here could be used to perform MRI-guided delivery of hydrophobic drugs.

Pegylated magnetic mesoporous silica nanoparticles decorated with AS1411 Aptamer as a targeting delivery system for cytotoxic agents

Fulfilling the purpose of developing a NP with theragnostic capabilities, the current study describes the synthesis of an aptamer-functionalized PEG-coated SPION/mesoporous silica core-shell nanoparticle for concurrent cancer targeted therapy and magnetic resonance imaging. SPIONs were synthesized according to a thermal decomposition method and served as cores for SPION/mesoporous silica core/shell nanoparticles (MMSNs). Doxorubicin was then successfully loaded in MMSNs which were then coated with di-carboxylic acid functionalized polyethylene glycol (PEG-MMSNs). AS1411 aptamers were at the end covalently attached to NPs (APT-PEG-MMSNs). The mean diameter of synthesized NPs was about 89 nm and doxorubicin encapsulation efficacy was ≈67.47%. Results of MTT based cell cytotoxicity assay demonstrated a significantly higher toxicity profile for APT-PEG-MMSNs against MCF7 cells compared to non-decorated MMSNs, while no significant differences were spotted against NIH-3T3 cells. Meanwhile, formation of protein corona around APT-PEG-MMSNs in biological medium significantly attenuated observed cytotoxicity against MCF7 cell line. Examining NPs uptake by MCF7 cells using confocal laser scanning microscopy also confirmed superiority of APT-PEG-MMSNs over PEG-MMSNs. Finally, APT decorated NPs induced highest signal intensity reduction in T₂-weighted images during in vitro MRI assay. In conclusion, developed NPs may serve as promising multifunctional vehicles for simultaneous cancer targeted therapy and MRI imaging.

Strategies to enhance efficacy of SPION-labeled stem cell homing by magnetic attraction: a systemic review with meta-analysis

Stem cells possess a promising potential in the clinical field. The application and effective delivery of stem cells to the desired target organ or site of injury plays an important role. This review describes strategies on understanding the effective delivery of stem cells labeled with superparamagnetic iron oxide nanoparticles (SPION) using an external magnet to enhance stem cell migration in vivo and in vitro. Fourteen total publications among 174 articles were selected. Stem cell type, SPION characteristics, labeling time, and magnetic force in vivo are considered important factors affecting the effective delivery of stem cells to the homing site. Most papers reported that the efficiency was increased when magnet is applied compared to those without. Ten studies analyzed the homing competency of SPION-labeled MSCs in vitro by observing the migration of the cell toward the external magnet. In cell-based experiments, the mechanism of magnetic attraction, the kind of nanoparticles, and various stem cells were studied well. Meta-analysis has shown the mean size of nanoparticles and degree of recovery or regeneration of damaged target organs upon in vivo studies. This strategy may provide a guideline for designing studies involving stem cell homing and further expand stem cell.

Carbodiimide Conjugation of Latent Transforming Growth Factor β1 to Superparamagnetic Iron Oxide Nanoparticles for Remote Activation

Conjugation of latent growth factors to superparamagnetic iron oxide nanoparticles (SPIONs) is potentially useful for magnetically triggered release of bioactive macromolecules. Thus, the goal of this work was to trigger the release of active Transforming Growth-Factor Beta (TGF-β) via magnetic hyperthermia by binding SPIONs to the latent form of TGF-β, since heat has been shown to induce release of TGF-β from the latent complex. Commercially available SPIONS with high specific absorption rates (SAR) were hydrolyzed in 70% ethanol to create surface carboxylic acid conjugation sites for carbodiimide chemistry. Fourier-Transform Infra-Red (FTIR) analysis verified the conversion of maleic anhydride to maleic acid. 1-Ethyl-2-(3-dimethyulaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (Sulfo-NHS) were used to bind to the open conjugation sites of the SPION in order to graft latent TGF-β onto the particles. The resulting conjugated particles were imaged with transmission electron microscopy (TEM), and the complexed particles were characterized by dynamic light scattering (DLS) and superconducting quantum interference device (SQUID) magnetometry. Enzyme-linked immunosorbent assay (ELISA) was used to assess the thermally triggered release of active TGF-β from the latent complex, demonstrating that conjugation did not interfere with release. Results showed that latent TGF-β was successfully conjugated to the iron oxide nanoparticles, and magnetically triggered release of active TGF-β was achieved.

Pluronic F127-Folate Coated Super Paramagenic Iron Oxide Nanoparticles as Contrast Agent for Cancer Diagnosis in Magnetic Resonance Imaging

Contrast agents have been widely used in medicine to enhance contrast in magnetic resonance imaging (MRI). Among them, super paramagnetic iron oxide nanoparticles (SPION) have been reported to have low risk in clinical use. In our study, F127-Folate coated SPION was fabricated in order to efficiently target tumors and provide imaging contrast in MRI. SPION alone have an average core size of 15 nm. After stabilizing with Pluronic F127, the nanoparticles reached a hydrodynamic size of 180 nm and dispersed well in various kinds of media. The F127-Folate coated SPION were shown to specifically target folate receptor expressing cancer cells by flow cytometry analysis, confocal laser scanning microscope, as well as in vitro MRI. Furthermore, in vivo MRI images have shown the enhanced negative contrast from the F127-Folate coated SPION in tumor-bearing mice. In conclusion, our F127-Folate coated SPION have shown great potential as a contrast agent in MRI, as well as in the combination with drug delivery for cancer therapy.

Magnetic Dehydrodipeptide-Based Self-Assembled Hydrogels for Theragnostic Applications

Self-assembled peptide hydrogels have emerged in recent years as the new paradigm in biomaterials research. We have contributed to this field the development of hydrogels based on dehydrodipeptides N-capped with naproxen. The dehydrodipeptide hydrogels can be loaded with drugs, thus being potential nanocarriers for drug delivery. In this work novel dehydrodipeptides containing tyrosine and aspartic acid amino acid residues N-capped with naproxen and C-terminal dehydrophenylalanine were prepared and characterized. Superparamagnetic iron oxide nanoparticles (SPIONs) were incorporated into the dehydrodipeptide-based hydrogels and their effect on the self-assembly, structure and rheological and magnetic properties of the hydrogels was studied. Magnetic hydrogels, with incorporated SPIONs, displayed concentration-dependent T₂-MRI contrast enhancement. Moreover, upon magnetic excitation (alternating magnetic field -AMF-) the SPIONs were able to generate a significant amount of heat. Hence, magnetic hyperthermia can be used as a remote trigger for release of drug cargos and SPIONs incorporated into the self-assembled dehydrodipeptide hydrogels.

Homogeneous Embedding of Magnetic Nanoparticles into Polymer Brushes during Simultaneous Surface-Initiated Polymerization

Here we present a facile and efficient method of controlled embedding of inorganic nanoparticles into an ultra-thin (<15 nm) and flat (~1.0 nm) polymeric coating that prevents unwanted aggregation. Hybrid polymer brushes-based films were obtained by simultaneous incorporation of superparamagnetic iron oxide nanoparticles (SPIONs) with diameters of 8⁻10 nm into a polycationic macromolecular matrix during the surface initiated atom transfer radical polymerization (SI-ATRP) reaction in an ultrasonic reactor. The proposed structures characterized with homogeneous distribution of separated nanoparticles that maintain nanometric thickness and strong magnetic properties are a good alternative for commonly used layers of crosslinked nanoparticles aggregates or bulk structures. Obtained coatings were characterized using atomic force microscopy (AFM) working in the magnetic mode, secondary ion mass spectrometry (SIMS), and X-ray photoelectron spectroscopy (XPS).

Superparamagnetic Iron Oxide Nanoparticles-Current and Prospective Medical Applications

The recent, fast development of nanotechnology is reflected in the medical sciences. Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are an excellent example. Thanks to their superparamagnetic properties, SPIONs have found application in Magnetic Resonance Imaging (MRI) and magnetic hyperthermia. Unlike bulk iron, SPIONs do not have remnant magnetization in the absence of the external magnetic field; therefore, a precise remote control over their action is possible. This makes them also useful as a component of the advanced drug delivery systems. Due to their easy synthesis, biocompatibility, multifunctionality, and possibility of further surface modification with various chemical agents, SPIONs could support many fields of medicine. SPIONs have also some disadvantages, such as their high uptake by macrophages. Nevertheless, based on the ongoing studies, they seem to be very promising in oncological therapy (especially in the brain, breast, prostate, and pancreatic tumors). The main goal of our paper is, therefore, to present the basic properties of SPIONs, to discuss their current role in medicine, and to review their applications in order to inspire future developments of new, improved SPION systems.

Effect of superparamagnetic nanoparticles coated with various electric charges on α-synuclein and β-amyloid proteins fibrillation process

Background

Most of nanoparticles are nontoxic and have high absorption capability. Therefore, nanoparticles binding can effectively restrain fibrillation of β-amyloid and α-synuclein proteins and eventually prevent the toxicity of pathogenesis peptide of Alzheimer. Super paramagnetic iron oxide nanoparticles (SPIONs) contain iron oxide core which can be connected to a special part through magnetic coating.

Materials and methods

In this study, the effect of SPIONs with different charges was simultaneously examined on the fibrillation of both β-amyloid and α-synuclein proteins by applying Thioflavin-T assay.

Results

According to the results of the investigation on amyloid-fibrillation mechanism in both β-amyloids and α-synucleins, it was revealed that negatively-charged nanoparticles encoded to –COOH by dextran-coating were able to have a considerable absorption decrease from 17,000–12,000 after 320 minutes delay to lag phase and decrease in binding level of thioflavin-T particles to β-sheets.

Conclusion

The different concentrations of these nanoparticles and special coating of each particle had an effect on the kinetics of β-amyloid and α-synuclein fibrillations.

Cell-Promoted Nanoparticle Aggregation Decreases Nanoparticle-Induced Hyperthermia under an Alternating Magnetic Field Independently of Nanoparticle Coating, Core Size, and Subcellular Localization

Magnetic hyperthermia has a significant potential to be a new breakthrough for cancer treatment. The simple concept of nanoparticle-induced heating by the application of an alternating magnetic field has attracted much attention, as it allows the local heating of cancer cells, which are considered more susceptible to hyperthermia than healthy cells, while avoiding the side effects of traditional hyperthermia. Despite the potential of this therapeutic approach, the idea that local heating effects due to the application of alternating magnetic fields on magnetic nanoparticle-loaded cancer cells can be used as a treatment is controversial. Several studies indicate that the heating capacity of magnetic nanoparticles is largely reduced in the cellular environment because of increased viscosity, aggregation, and dipolar interactions. However, an increasing number of studies, both in vitro and in vivo, show evidence of successful magnetic hyperthermia treatment on several different types of cancer cells. This apparent contradiction might be due to the use of different experimental conditions. Here, we analyze the effects of several parameters on the cytotoxic efficiency of magnetic nanoparticles as heat inductors under an alternating magnetic field. Our results indicate that the cell-nanoparticle interaction reduces the cytotoxic effects of magnetic hyperthermia, independent of nanoparticle coating and core size, the cell line used, and the subcellular localization of nanoparticles. However, there seems to occur a synergistic effect between the application of an external source of heat and the presence of magnetic nanoparticles, leading to higher toxicities than those induced by heat alone or the accumulation of nanoparticles within cells.

Iron oxide nanoparticles: Diagnostic, therapeutic and theranostic applications

Many different iron oxide nanoparticles have been evaluated over the years, for a wide variety of biomedical applications. We here summarize the synthesis, surface functionalization and characterization of iron oxide nanoparticles, as well as their (pre-) clinical use in diagnostic, therapeutic and theranostic settings. Diagnostic applications include liver, lymph node, inflammation and vascular imaging, employing mostly magnetic resonance imaging but recently also magnetic particle imaging. Therapeutic applications encompass iron supplementation in anemia and advanced cancer treatments, such as modulation of macrophage polarization, magnetic fluid hyperthermia and magnetic drug targeting. Because of their properties, iron oxide nanoparticles are particularly useful for theranostic purposes. Examples of such setups, in which diagnosis and therapy are intimately combined and in which iron oxide nanoparticles are used, are image-guided drug delivery, image-guided and microbubble-mediated opening of the blood-brain barrier, and theranostic tissue engineering. Together, these directions highlight the versatility and the broad applicability of iron oxide nanoparticles, and indicate the integration in future medical practice of multiple iron oxide nanoparticle-based materials.

Iron oxide nanoparticles: Diagnostic, therapeutic and theranostic applications

Many different iron oxide nanoparticles have been evaluated over the years, for a wide variety of biomedical applications. We here summarize the synthesis, surface functionalization and characterization of iron oxide nanoparticles, as well as their (pre-) clinical use in diagnostic, therapeutic and theranostic settings. Diagnostic applications include liver, lymph node, inflammation and vascular imaging, employing mostly magnetic resonance imaging but recently also magnetic particle imaging. Therapeutic applications encompass iron supplementation in anemia and advanced cancer treatments, such as modulation of macrophage polarization, magnetic fluid hyperthermia and magnetic drug targeting. Because of their properties, iron oxide nanoparticles are particularly useful for theranostic purposes. Examples of such setups, in which diagnosis and therapy are intimately combined and in which iron oxide nanoparticles are used, are image-guided drug delivery, image-guided and microbubble-mediated opening of the blood-brain barrier, and theranostic tissue engineering. Together, these directions highlight the versatility and the broad applicability of iron oxide nanoparticles, and indicate the integration in future medical practice of multiple iron oxide nanoparticle-based materials.

A Hybrid System for Magnetic Hyperthermia and Drug Delivery: SPION Functionalized by Curcumin Conjugate

Cancer is among the leading causes of death worldwide, thus there is a constant demand for new solutions, which may increase the effectiveness of anti-cancer therapies. We have designed and successfully obtained a novel, bifunctional, hybrid system composed of colloidally stabilized superparamagnetic iron oxide nanoparticles (SPION) and curcumin containing water-soluble conjugate with potential application in anticancer hyperthermia and as nanocarriers of curcumin. The obtained nanoparticulate system was thoroughly studied in respect to the size, morphology, surface charge, magnetic properties as well as some biological functions. The results revealed that the obtained nanoparticles, ca. 50 nm in diameter, were the agglomerates of primary particles with the magnetic, iron oxide cores of ca. 13 nm, separated by a thin layer of the applied cationic derivative of chitosan. These agglomerates were further coated with a thin layer of the sodium alginate conjugate of curcumin and the presence of both polymers was confirmed using thermogravimetry. The system was also proven to be applicable in magnetic hyperthermia induced by the oscillating magnetic field. A high specific absorption rate (SAR) of 280 [W/g] was registered. The nanoparticles were shown to be effectively uptaken by model cells. They were found also to be nontoxic in the therapeutically relevant concentration in in vitro studies. The obtained results indicate the high application potential of the new hybrid system in combination of magnetic hyperthermia with delivery of curcumin active agent.

Magnetic resonance sentinel lymph node imaging and magnetometer-guided intraoperative detection in prostate cancer using superparamagnetic iron oxide nanoparticles

Purpose

Sentinel lymph node (LN) dissection (sLND) using a magnetometer and superpara-magnetic iron oxide nanoparticles (SPION) as a tracer was successfully applied in prostate cancer (PCa). The feasibility of sentinel LN (SLN) visualization on MRI after intraprostatic SPION injection has been reported. In the present study, results of preoperative MRI identification of SLNs and the outcome of subsequent intraoperative magnetometer-guided sLND following intraprostatic SPION injection were studied in intermediate- and high-risk PCa.

Patients and methods

A total of 50 intermediate- and high-risk PCa patients (prostate-specific antigen >10 ng/mL and/or Gleason score ≥7) scheduled for radical prostatectomy with magnetometer-guided sLND and extended pelvic LND (eLND), were included. Patients underwent MRI before and one day after intraprostatic SPION injection using T1-, T2-, and T2*-weighted sequences. Diagnostic rate per patient was established. Distribution of SLNs per anatomic region was registered. Diagnostic accuracy of sLND was assessed by using eLND as a reference standard.

Results

SPION-MRI identified a total of 890 SLNs (median 17.5; IQR 12–22.5). SLNs could be successfully detected using MRI in all patients (diagnostic rate 100%). Anatomic SLN distribution: external iliac 19.2%, common iliac 16.6%, fossa obturatoria 15.8%, internal iliac 13.8%, presacral 12.1%, perirectal 12.0%, periprostatic 3.7%, perivesical 2.3%, and other regions 4.4%. LN metastases were intraoperatively found in 15 of 50 patients (30%). sLND had a 100% diagnostic rate, 85.7% sensitivity, 97.2% specificity, 92.3% positive predictive value, 94.9% negative predictive value, false negative rate 14.3%, and 2.8% additional diagnostic value (LN metastases only outside the eLND template).

Conclusion

MR scintigraphy after intraprostatic SPION injection provides a roadmap for intraoperative magnetometer-guided SLN detection and can be useful to characterize a reliable lymphadenectomy template. Draining LN from the prostate can be identified in an unexpectedly high number, especially outside the established eLND template. Further studies are required to analyze discordance between the number of pre- and intraoperatively identified SLNs.

Using superparamagnetic iron oxide nanoparticles to enhance bioavailability of quercetin in the intact rat brain

Background

Quercetin (QT) as a bioactive flavonoid has a potential therapeutic activity for numerous neuronal injuries and neurodegenerative diseases. However, the low absorption rate of QT, especially through the blood-brain barrier, restricts its bioactivity in the body. The current research took the advantage of superparamagnetic iron oxide nanoparticles (SPIONs) to enhance the bioavailability of quercetin.

Methods

Quercetin conjugated with SPIONs was prepared by means of nanoprecipitation method and was characterized by X-ray diffractometer, scanning electron microscope, and Fourier transformed infrared spectrometer analyses. Wistar male rats were orally fed by gavage with QT and QT-SPION at 50 and 100 mg/kg daily doses for 7 days. Using high-performance liquid chromatography (HPLC) method, biodistribution of QT was evaluated in plasma and brain tissue.

Results

The outcomes of this research revealed a higher concentration in the plasma and brain of the rats fed with QT-SPION in comparison to free QT.

Conclusion

The results of this study confirm that SPION as a targeted drug delivery system enhances the bioavailability of quercetin in the brain about ten folds higher than free quercetin and could be used for the treatment of neurodegenerative disorders.

Formulation and in vitro evaluation of a siRNA delivery nanosystem decorated with gH625 peptide for triple negative breast cancer theranosis

The development of an efficient small interfering RNA (siRNA) delivery system has held scientists interest since the discovery of the RNA interference mechanism (RNAi). This strategy gives hope for the treatment of many severe diseases. Herein, we developed hybrid nanovectors able to deliver siRNA to triple negative breast cancer cells. The nanovectors are based on PEGylated superparamagnetic iron oxide nanoparticles (SPION) functionalized with gH625 peptide, chitosan and poly-l-arginine. Every component has a key role and specific function: SPION is the core scaffolding the nanovector; PEG participates in the colloidal stability and the immune stealthiness; gH625 peptide promotes the nanovector internalization into cancer cells; cationic polymers provide the siRNA protection and favor siRNA endosomal escape and delivery to cytosol. The formulation was optimized by varying the amount of each compound. The efficacy of the siRNA retention and protection were investigated in the presence of high concentration of serum. Optimized nanovectors show a high uptake by MDA-MB-231 cells. The resulting down regulation of GFP expression was 73 ± 3% with our nanovector compared to 59 ± 8% obtained with the siRNA-Oligofectamine™ complex in the same conditions.

Simultaneous Preclinical Positron Emission Tomography-Magnetic Resonance Imaging Study of Lymphatic Drainage of Chelator-Free 64Cu-Labeled Nanoparticles

BACKGROUND

Hybrid positron emission tomography (PET)-magnetic resonance imaging (MRI) systems have been taken in use as new clinical diagnostic tools including detection and therapy planning of cancer. To reduce the amount of contrast agents injected in patients while fully benefitting both modalities, dual-modality probes are required.

MATERIAL AND METHODS

This study was first aimed at developing a hybrid PET-MRI probe by labeling superparamagnetic iron oxide nanoparticles (SPIONs) with ⁶⁴Cu using a fast and chelator-free conjugation method, and second, to demonstrate the ability of the agent to target sentinel lymph nodes (SLNs) in vivo using simultaneous PET-MRI imaging.

RESULTS

High labeling efficiency of 97% produced within 10-15 min was demonstrated at room temperature. ⁶⁴Cu-SPIONs were chemically stable in mouse serum for 24 h and after intradermal injection in the hind paw of C57BL/6J mice, demonstrated specific accumulation in the SLN. Simultaneous PET-MRI clearly demonstrated visualization of ⁶⁴Cu-SPIONs, in dynamic and static imaging sequences up to 24 h after administration.

CONCLUSION

The use of a single hybrid probe and simultaneous hybrid imaging provides an efficient, complementary integration of quantitation and is expected to improve preoperative planning and intraoperative guidance of cancer treatments.

NRP-1 targeted and cargo-loaded exosomes facilitate simultaneous imaging and therapy of glioma in vitro and in vivo

Currently, glioma treatment is limited by two main factors: timely detection at onset or relapse and restriction of drugs by the blood-brain barrier (BBB) from entering the brain and influencing tumor growth. However, a safe BBB-traversing drug delivery system has brought new hope to glioma treatment. Exosomes have strong cargo-loading capacity and have the ability to cross the BBB. They can also be conferred with the ability for targeted delivery. Therefore, exosomes have great promise to be a targeted drug delivery vehicles. In this study, we firstly loaded superparamagnetic iron oxide nanoparticles (SPIONs) and curcumin (Cur) into exosomes and then conjugated the exosome membrane with neuropilin-1-targeted peptide (RGERPPR, RGE) by click chemistry to obtain glioma-targeting exosomes with imaging and therapeutic functions. When administered to glioma cells and orthotopic glioma models, we found that these engineered exosomes could cross the BBB smoothly and provided good results for targeted imaging and therapy of glioma. Furthermore, SPION-mediated magnetic flow hyperthermia (MFH) and Cur-mediated therapy also showed a potent synergistic antitumor effect. Therefore, the diagnostic and therapeutic effects on glioma were significantly improved, while reducing the side effects. We have designed a new type of glioma-targeting exosomes, which can carry nanomaterials and chemical agents for simultaneous diagnosis and treatment of glioma, thus providing a potential approach for improving the diagnosis and treatment effects of intracranial tumors.

Mucin-1 aptamer-armed superparamagnetic iron oxide nanoparticles for targeted delivery of doxorubicin to breast cancer cells

Introduction: Superparamagnetic iron oxide nanoparticles (SPIONs) can be functionalized with various agents (e.g., targeting and therapeutic agents) and used for targeted imaging/therapy of cancer. In the present study, we engineered doxorubicin (DOX)-conjugated anti-mucin -1 (MUC-1) aptamer (Ap)-armed PEGylated SPIONs for targeted delivery of DOX molecules to the breast cancer MCF-7 cells. Methods: The SPIONs were synthesized using the thermal decomposition method and modified by polyethylene glycol (PEG) to maximize their biocompatibility and minimize any undesired cytotoxicity effects. Subsequently, DOX molecules were loaded onto the SPIONs, which were further armed with amine-modified MUC-1 aptamer by EDC/NHS chemistry. Results: The morphologic and size analyses of nanoparticles (NPs) by transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed spherical and monodisperse MNPs with a size range of 5-64 nm. The FT-IR spectrophotometry and 1 HNMR analysis confirmed the surface modification of NPs. The cytotoxicity assay of the aptamer-armed MNPs exhibited a higher death rate in the MUC-1 over-expressing MCF-7 cells as compared to the MUC-1 under-expressing MDA-MB-231 cells. The flow cytometry analysis of the engineered Ap-armed SPIONs revealed a higher uptake as compared to the SPIONs alone. Conclusion: Based on our findings, the anti-MUC-1 Ap-armed PEGylated SPIONs loaded with DOX molecules could serve as an effective multifunctional theranostics for simultaneous detection and eradication of MUC-1-positive breast cancer cells.