Reconstruction of TNF-α with specific isoelectric point released from SPIONs basing on variable charge to enhance pH-sensitive controlled-release.

The clinical application of tumor necrosis factor-α (TNF-α) is limited by its short half-life, subeffective concentration in the targeted area and severe systemic toxicity. In this study, the recombinant polypeptide S4-TNF-α was constructed and coupled with chitosan-modified superparamagnetic iron oxide nanoparticles (S4-TNF-α-SPIONs) to achieve pH-sensitive controlled release and active tumor targeting activity. The isoelectric point (pI) of S4-TNF-α was reconstructed to approach the pH of the tumor microenvironment. The negative-charge S4-TNF-α was adsorbed to chitosan-modified superparamagnetic iron oxide nanoparticles (CS-SPIONs) with a positive charge through electrostatic adsorption at physiological pH. The acidic tumor microenvironment endowed S4-TNF-α with a zero charge, which accelerated S4-TNF-α release from CS-SPIONs. Our studies showed that S4-TNF-α-SPIONs displayed an ideal pH-sensitive controlled release capacity and improved antitumor effects. Our study presents a novel approach to enhance the pH-sensitive controlled-release of genetically engineered drugs by adjusting their pI to match the pH of the tumor microenvironment.

Magnetic Resonance Imaging-Based Monitoring of the Accumulation of Polyethylene Terephthalate Nanoplastics.

Polyethylene terephthalate (PET) is one of the most produced plastic materials in the world. The emergence of microplastics and nanoplastics (MPs/NPs) as a significant environmental contaminant has become a matter of increasing concern. While the toxicological effects of PET NPs have been widely researched, there is a lack of methodologies for studying their accumulation. The present study introduces a novel method to monitor the distribution of PET NPs in germinating wheat (Triticum aestivum L.) seeds. This involves the functionalization of superparamagnetic iron oxide nanoparticles (SPIONs) with PET NPs (PET-fSPIONs) coupled with magnetic resonance microimaging (µMRI) to provide insight into their distribution within the seed. The present study has demonstrated that PET-fSPIONs accumulate in specific regions of germinating wheat seeds, including the shoot apical meristem, the radicle, the coleoptile, the plumule, and the scutellum. Furthermore, the accumulation of PET-fSPIONs has been shown to exert a discernible effect on spin-spin relaxation (T2), as observed via MRI and quantitative T2 relaxation time analysis. The accumulation of PET NPs in embryo regions was also confirmed by SEM. Diffusion-weighted magnetic resonance imaging (DW-MRI) and non-invasive chemical shift imaging analyses demonstrated that PET NPs resulted in restricted diffusion within the highlighted areas, as well as an impact on lipid content. Our study reveals that using µMRI with fSPIONs provides a non-invasive method to monitor the biodistribution of PET nanoparticles in wheat seeds. Additionally, it offers valuable insights into the microstructural interactions of PET.

Enhanced 129 Xe T1 relaxation in whole blood and in the presence of SPIONs at low magnetic field strengths.

PURPOSE: To compare the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on the T1 of 129 Xe and 1 H and to measure the relaxation of 129 Xe in blood at low and high magnetic field strengths. METHODS: 129 Xe and 1 H T1 relaxometry was performed at low- and high-field strengths in samples containing different SPION concentrations, while imaging was used to compare the contrast obtainable in these two field regimes. In vivo experiments at variable field strengths were performed to determine the depolarization of 129 Xe in blood and the feasibility of in vivo dissolved-phase spectroscopy and imaging at low field. RESULTS: The SPION relaxivity was substantially greater at low field for 1 H, increasing from 0.92 ± 0.06 mM s-1 at 11.7T to 31.5 ± 1.8 mM s-1 at 0.6 mT, and for 129 Xe, which increased from 0.13 ± 0.03 mM s-1 at 11.7T to 7.32 ± 0.71 mM s-1 at 2.1 mT. The additional MR signal loss increased from 0.7% at 9.4T to 20.6 ± 4.2% at 0.6 mT for 1 H and from -0.7 ± 3.4% at 9.4T to 12.7 ± 3.5% at 2.1 mT for 129 Xe. Blood was found to depolarize 129 Xe below 3T in a manner inversely proportional to the field strength. In vitro studies at 2.1 mT suggest 129 Xe relaxation times below 5 s in blood dilutions as low as 0.4% volume. CONCLUSION: SPIONs longitudinal relaxivity increases at low field both for 1 H and 129 Xe. The depolarization of xenon in blood, which is found to increase below 3T, effectively prevents in vivo dissolved-phase spectroscopy and imaging at low-field strengths.

A new bimodal approach for sentinel lymph node imaging in prostate cancer using a magnetic and fluorescent hybrid tracer.

PURPOSE: To obtain initial data on sentinel lymph node (SLN) visualisation by pre-operative magnetic resonance imaging (MRI) and intra-operative bimodal SLN identification using a new magnetic fluorescent hybrid tracer in prostate cancer (PCa) patients. METHODS: Ten patients at > 5% risk for lymph node (LN) invasion were included. The day before surgery, a magnetic fluorescent hybrid tracer consisting of superparamagnetic iron oxide nanoparticles (SPION) and indocyanine green was transrectally injected into the prostate. Five hours after injection, transversal pelvic MRI scans were recorded and T2*-weighed images were screened for pelvic LNs with SPION uptake. Intra-operatively, magnetically active and/or fluorescent SLNs were detected by a handheld magnetometer and near-infrared fluorescence imaging (FI). Extended pelvic lymph node dissection (PLND) and radical prostatectomy completed the surgery. All resected specimens were checked ex situ for magnetic activity and fluorescence and were histopathologically examined. RESULTS: Pre-operative MRI identified 145 pelvic LNs with SPION uptake. In total, 75 (median 6, range 3‒13) magnetically active SLNs were resected, including 14 SLNs not seen on MRI. FI identified 89 fluorescent LNs (median 8.5, range 4‒13) of which 15 LNs were not magnetically active. Concordance of the different techniques was 70% for pre-operative MRI vs. magnetometer-guided PLND and 88% for magnetic vs. fluorescent SLN detection. CONCLUSION: These are the first promising results of bimodal, magnetic fluorescent SLN detection in PCa patients. Our magnetic fluorescent hybrid approach provides the surgeon a pre-operative lymphatic roadmap by using MRI and intra-operative visual guidance through the application of a fluorescent lymphatic agent. The diagnostic accuracy of our new hybrid approach has to be evaluated in further studies. TRIAL REGISTRATION: DRKS00032808. Registered 04 October 2023, retrospectively registered.

Imaging the Magnetization of Single Magnetite Nanoparticle Clusters via Photothermal Circular Dichroism.

Magnetic imaging is a versatile tool in biological and condensed-matter physics. Existing magnetic imaging techniques either require demanding experimental conditions which restrict the range of their applications or lack the spatial resolution required for single-particle measurements. Here, we combine photothermal (PT) microscopy with magnetic circular dichroism (MCD) to develop a versatile magnetic imaging technique using visible light. Unlike most magnetic imaging techniques, photothermal magnetic circular dichroism (PT MCD) microscopy works particularly well for single nanoparticles immersed in liquids. As a proof of principle, we demonstrate magnetic CD imaging of superparamagnetic magnetite nanoparticulate clusters immersed in microscope immersion oil. The sensitivity of our method allowed us to probe the magnetization curve of single ∼400-nm-diameter magnetite nanoparticulate clusters.

Upcycling of Acid-Leaching Solutions from Li-Ion Battery Waste Treatment through the Facile Synthesis of Magnetorheological Fluid.

The rapidly growing production and usage of lithium-ion batteries (LIBs) dramatically raises the number of harmful wastes. Consequently, the LIBs waste management processes, taking into account reliability, efficiency, and sustainability criteria, became a hot issue in the context of environmental protection as well as the scarcity of metal resources. In this paper, we propose for the first time a functional material-a magnetorheological fluid (MRF) from the LIBs-based liquid waste containing heavy metal ions. At first, the spent battery waste powder was treated with acid-leaching, where the post-treatment acid-leaching solution (ALS) contained heavy metal ions including cobalt. Then, ALS was used during wet co-precipitation to obtain cobalt-doped superparamagnetic iron oxide nanoparticles (SPIONs) and as an effect, the harmful liquid waste was purified from cobalt. The obtained nanoparticles were characterized with SEM, TEM, XPS, and magnetometry. Subsequently, superparamagnetic nanoparticles sized 15 nm average in diameter and magnetization saturation of about 91 emu g-1 doped with Co were used to prepare the MRF that increases the viscosity by about 300% in the presence of the 100 mT magnetic fields. We propose a facile and cost-effective way to utilize harmful ALS waste and use them in the preparation of superparamagnetic particles to be used in the magnetorheological fluid. This work describes for the first time the second life of the battery waste in the MRF and a facile way to remove the harmful ingredients from the solutions obtained after the acid leaching of LIBs as an effective end-of-life option for hydrometallurgical waste utilization.

SPION based magnetic PLGA nanofibers for neural differentiation of mesenchymal stem cells.

Recently, magnetic platforms have been widely investigated in diagnostic, therapeutic and research applications due to certain properties, such as cell and tissue tracking and imaging, thermal therapy and being dirigible. In this study, the incorporation of magnetic nanoparticles (MNPs) in nanofibers has been proposed to combine the advantages of both nanofibers and MNPs to induce neural differentiation of mesenchymal stem cells. Magnetic poly (lactic-co-glycolic acid) nanofibers (containing 0%, 5% and 10% SPION) were fabricated and utilized as the matrix for the differentiation of mesenchymal stem cells (MSCs). Morphological, magnetic and mechanical properties were analyzed using FESEM, VSM and tensile test, respectively. The expression of neural markers (TUJ-1, NSE, MAP-2) was assessed quantitative and qualitatively utilizing RT-PCR and immunocytochemistry. Results confirmed the incorporation of MNPs in nanofibrous scaffold, presenting a saturation magnetization of 9.73 emu g-1. Also, with increase in magnetic particle concentration (0%-10%), tensile strength increased from 4.08 to 5.85 MPa, whereas the percentage of elongation decreased. TUJ-1 expression was 3.8 and 1.8 fold for 10% and 5% magnetic scaffold (versus non-magnetic scaffold) respectively, and the expression of NSE was 6.3 and 1.2-fold for 10% and 5%, respectively. Consequently, it seems that incorporation of magnetic biomaterial can promote the neural differentiation of MSCs, during which the augmentation of super paramagnetic iron oxide concentration from 0% to 10% accelerates the neural differentiation process.

Atranorin driven by nano materials SPION lead to ferroptosis of gastric cancer stem cells by weakening the mRNA 5-hydroxymethylcytidine modification of the Xc-/GPX4 axis and its expression.

Gastric cancer is a highly malignant tumor. Gastric cancer stem cells (GCSCs) are the main causes of drug resistance, metastasis, recurrence, and poor prognosis. As a secondary metabolite of lichen, Atranorin has a variety of biological effects, such as antibacterial, anti-inflammatory, analgesic, and wound healing; however, its killing effect on GCSCs has not been reported. In this study, we constructed Atranorin complexes comprising superparamagnetic iron oxide nanoparticles (SPION) (Atranorin@SPION). In vitro and in vivo experiments confirmed that Atranorin@SPION could significantly inhibit the proliferation, invasion, angiogenesis, and tumorigenicity of CD44+/ CD24+ GCSCs, and induce oxidative stress injury, Fe2+ accumulation, and ferroptosis. Quantitative real-time reverse transcription PCR and western blotting results showed that Atranorin@SPION not only reduced the expression levels of GCSC stem cell markers and cell proliferation and division markers, but also significantly inhibited the expression levels of key molecules in the cystine/glutamate transporter (Xc-)/glutathione peroxidase 4 (GPX4) and Tet methylcytosine dioxygenase (TET) family proteins. The results of high performance liquid chromatography-mass spectrometry and Dot blotting showed that Atranorin@SPION significantly inhibited the mRNA 5­hydroxymethylcytidine modification of GCSCs. Meanwhile, the results of RNA immunoprecipitation-PCR also indicated that Atranorin@SPIONs significantly reduced the 5-hydroxymethylcytidine modification level of GPX4 and SLC7A11 mRNA 3' untranslated region in GCSCs, resulting in a decrease in their stability, shortening their half-lives and reducing translation activity. Therefore, this study revealed that Atranorin@SPIONs induced ferroptosis of GCSCs by weakening the expression of the Xc-/GPX4 axis and the 5-hydroxymethylcytidine modification of mRNAs in the pathway, thereby achieving their therapeutic effect on gastric cancer.

Toxicological effects of the mixed iron oxide nanoparticle (Fe3O4 NP) on murine fibroblasts LA-9.

The increase in large-scale production of magnetic nanoparticles (NP) associated with the incomplete comprehensive knowledge regarding the potential risks of their use on environmental and human health makes it necessary to study the biological effects of these particles on organisms at the cellular level. The aim of this study to examine the cellular effects on fibroblast lineage LA-9 after exposure to mixed iron oxide NP (Fe3O4 NP). The following analyses were performed: field emission gun-scanning electron microscopy (SEM-FEG), dynamic light scattering (DLS), zeta potential, ultraviolet/visible region spectroscopy (UV/VIS), and attenuated total reactance-Fourier transform infrared (ATR-FTIR) spectroscopy analyses for characterization of the NP. The assays included cell viability, morphology, clonogenic potential, oxidative stress as measurement of reactive oxygen species (ROS) and nitric oxide (NO) levels, cytokines quantification interleukin 6 (IL-6) and tumor necrosis factor (TNF), NP uptake, and cell death. The size of Fe3O4 NP was 26.3 nm when evaluated in water through DLS. Fe3O4 NP did not reduce fibroblast cell viability until the highest concentration tested (250 µg/ml), which showed a decrease in clonogenic potential as well as small morphological changes after exposure for 48 and 72 hr. The NP concentration of 250 µg/ml induced enhanced ROS and NO production after 24 hr treatment. The uptake assay exhibited time-dependent Fe3O4 NP internalization at all concentrations tested with no significant cell death. Hence, exposure of fibroblasts to Fe3O4 NP-induced oxidative stress but not reduced cell viability or death. However, the decrease in the clonogenic potential at the highest concentration demonstrates cytotoxic effects attributed to Fe3O4 NP which occurred on the 7th day after exposure.

Intravenous SPION-labeled adipocyte-derived stem cells targeted to the brain by magnetic attraction in a rat stroke model: An ultrastructural insight into cell fate within the brain.

Mesenchymal stem cell therapy after stroke is a promising option investigated in animal models and clinical trials. The intravenous route is commonly used in clinical settings guaranteeing an adequate safety profile although low yields of engraftment. In this report, rats subjected to ischemic stroke were injected with adipose-derived stem cells (ADSCs) labeled with superparamagnetic iron oxide nanoparticles (SPIONs) applying an external magnetic field in the skull to retain the cells. Although most published studies demonstrate viability of ADSCs, only a few have used ultrastructural techniques. In our study, the application of a local magnetic force resulted in a tendency for higher yields of SPION-ADSCs targeting the brain. However, grafted cells displayed morphological signs of death, one day after administration, and correlative microscopy showed active microglia and astrocytes associated in the process of scavenging. Thus, we conclude that, although successfully targeted within the brain, SPION-ADSCs viability was rapidly compromised.

Anticancer Nanotherapeutics in Clinical Trials: The Work behind Clinical Translation of Nanomedicine.

The ultimate goal of nanomedicine has always been the generation of translational technologies that can ameliorate current therapies. Cancer disease represented the primary target of nanotechnology applied to medicine, since its clinical management is characterized by very toxic therapeutics. In this effort, nanomedicine showed the potential to improve the targeting of different drugs by improving their pharmacokinetics properties and to provide the means to generate new concept of treatments based on physical treatments and biologics. In this review, we considered different platforms that reached the clinical trial investigation, providing an objective analysis about their physical and chemical properties and the working mechanism at the basis of their tumoritr opic properties. With this review, we aim to help other scientists in the field in conceiving their delivering platforms for clinical translation by providing solid examples of technologies that eventually were tested and sometimes approved for human therapy.

Controlling Macrophage Polarization to Modulate Inflammatory Cues Using Immune-Switch Nanoparticles.

The persistence of inflammatory mediators in tissue niches significantly impacts regenerative outcomes and contributes to chronic diseases. Interleukin-4 (IL4) boosts pro-healing phenotypes in macrophages (Mφ) and triggers the activation of signal transducer and activator of transcription 6 (STAT6). Since the IL4/STAT6 pathway reduces Mφ responsiveness to inflammation in a targeted and precise manner, IL4 delivery offers personalized possibilities to overcome inflammatory events. Despite its therapeutic potential, the limited success of IL4-targeted delivery is hampered by inefficient vehicles. Magnetically assisted technologies offer precise and tunable nanodevices for the delivery of cytokines by combining contactless modulation, high tissue penetration, imaging features, and low interference with the biological environment. Although superparamagnetic iron oxide nanoparticles (SPION) have shown clinical applicability in imaging, SPION-based approaches have rarely been explored for targeted delivery and cell programming. Herein, we hypothesized that SPION-based carriers assist in efficient IL4 delivery to Mφ, favoring a pro-regenerative phenotype (M2φ). Our results confirmed the efficiency of SPION-IL4 and Mφ responsiveness to SPION-IL4 with evidence of STAT6-mediated polarization. SPION-IL4-treated Mφ showed increased expression of M2φ associated-mediators (IL10, ARG1, CCL2, IL1Ra) when compared to the well-established soluble IL4. The ability of SPION-IL4 to direct Mφ polarization using sophisticated magnetic nanotools is valuable for resolving inflammation and assisting innovative strategies for chronic inflammatory conditions.

Heparin-Superparamagnetic Iron Oxide Nanoparticles for Theranostic Applications.

In this study, superparamagnetic iron oxide nanoparticles (SPIONs) were engineered with an organic coating composed of low molecular weight heparin (LMWH) and bovine serum albumin (BSA), providing heparin-based nanoparticle systems (LMWH@SPIONs). The purpose was to merge the properties of the heparin skeleton and an inorganic core to build up a targeted theranostic nanosystem, which was eventually enhanced by loading a chemotherapeutic agent. Iron oxide cores were prepared via the co-precipitation of iron salts in an alkaline environment and oleic acid (OA) capping. Dopamine (DA) was covalently linked to BSA and LMWH by amide linkages via carbodiimide coupling. The following ligand exchange reaction between the DA-BSA/DA-LMWH and OA was conducted in a biphasic system composed of water and hexane, affording LMWH@SPIONs stabilized in water by polystyrene sulfonate (PSS). Their size and morphology were investigated via dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The LMWH@SPIONs' cytotoxicity was tested, showing marginal or no toxicity for samples prepared with PSS at concentrations of 50 µg/mL. Their inhibitory activity on the heparanase enzyme was measured, showing an effective inhibition at concentrations comparable to G4000 (N-desulfo-N-acetyl heparin, a non-anticoagulant and antiheparanase heparin derivative; Roneparstat). The LMWH@SPION encapsulation of paclitaxel (PTX) enhanced the antitumor effect of this chemotherapeutic on breast cancer cells, likely due to an improved internalization of the nanoformulated drug with respect to the free molecule. Lastly, time-domain NMR (TD-NMR) experiments were conducted on LMWH@SPIONs obtaining relaxivity values within the same order of magnitude as currently used commercial contrast agents.

Fabrication of deferasirox-decorated aptamer-targeted superparamagnetic iron oxide nanoparticles (SPION) as a therapeutic and magnetic resonance imaging agent in cancer therapy.

In the current study, the synthesis of a theranostic platform composed of superparamagnetic iron oxide nanoparticles (SPION)-deferasirox conjugates targeted with AS1411 DNA aptamer was reported. In this regard, SPION was amine-functionalized by (3-aminopropyl)trimethoxysilane (ATPMS), and then deferasirox was covalently conjugated onto its surface. Finally, to provide guided drug delivery to cancerous tissue, AS1411 aptamer was conjugated to the complex of SPION-deferasirox. The cellular toxicity assay on CHO, C-26 and AGS cell lines verified higher cellular toxicity of targeted complex in comparison with non-targeted one. The evaluation of in vivo tumor growth inhibitory effect in C26 tumor-bearing mice illustrated that the aptamer-targeted complex significantly enhanced the therapeutic outcome in comparison with both non-targeted complex and free drug. The diagnostic capability of the prepared platform was also evaluated implementing C26-tumor-bearing mice. Obtained data confirmed higher tumor accumulation and higher tumor residence time for targeted complex through MRI imaging due to the existence of SPION as a contrast agent in the core of the prepared complex. The prepared multimodal theranostic system provides a safe and effective platform for fighting against cancer.

Fabrication and evaluation of aptamer-conjugated paclitaxel-loaded magnetic nanoparticles for targeted therapy on breast cancer cells.

Targeted drug delivery vehicles make it possible to deliver anti-cancer drugs to the cells or tissues of interest. Aptamers are peptide or oligonucleotide molecules that can serve as targeting elements of drug carriers. In the current study, we evaluated the capacity of an aptamer-based drug carrier to deliver Paclitaxel (PTX) to cancer cells. After being synthesized, SPIONs@PTX-SYL3C aptamer was characterized using different methods, including differential light scattering (DLS), infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Encapsulation efficiency (EE) and loading efficiency (LE) were also evaluated. The carrier was applied on 4T1, MCF 7, and MCF-10A breast cell lines to evaluate its drug delivery potency and specificity. EE and LE were calculated to be 77.6% and 7.76%, respectively. MTT results revealed that aptameric SPIONs@PTX was more toxic than non-aptameric SPIONs@PTX. Flowcytometry analysis and DAPI staining confirmed that SPIONs@PTX-Aptamer had higher cell internalization rate when compared to non-targeted SPIONs@PTX. Our results indicate that aptamer-conjugated SPIONs@PTX has a good capacity in recognizing its target cells and inhibiting their growth and division.

Blockade of HIF-1α and STAT3 by hyaluronate-conjugated TAT-chitosan-SPION nanoparticles loaded with siRNA molecules prevents tumor growth.

HIF-1α and STAT3 are two of the critical factors in the growth, proliferation, and metastasis of cancer cells and play a crucial role in inhibiting anti-cancer immune responses. Therefore, we used superparamagnetic iron oxide (SPION) nanoparticles (NPs) coated with thiolated chitosan (ChT) and trimethyl chitosan (TMC) and functionalized with hyaluronate (H) and TAT peptide for delivery of siRNA molecules against STAT3 and HIF-1α to cancer cells both in vivo and in vitro. The results indicated that tumor cell transfection with siRNA-encapsulated NPs robustly inhibited proliferation and migration and induced apoptosis in tumor cells. Furthermore, simultaneous silencing of HIF-1α and STAT3 significantly repressed cancer development in two different tumor types (4T1 breast cancer and CT26 colon cancer) which were associated with upregulation of cytotoxic T lymphocytes and IFN-γ secretion. The findings suggest inhibiting the HIF-1α/STAT3 axis by SPION-TMC-ChT-TAT-H NPs as an effective way to treat cancer.

Theranostics for Breast Cancer Stem Cells.

Effectively targeting and treating breast cancer stem cells (BCSCs), which have been linked to tumor development and metastasis, and recurrence still remains a challenging issue in preclinic and clinic. Screening and identifying characteristic BCSC biomarkers is important for distinguishing BCSCs from differentiated tumor cells within the tumor mass. Molecular imaging and nanotechnology are evolving as new fields that have a potentially high research and clinical impact. Developing the biocompatible contrast agents conjugated with high-affinity biomarker to selectively target BCSCs and is one of the key prerequisites for image-guided diagnosis and monitoring therapy of BCSCs. Very recently, we documented the extra domain-B fibronectin (EDB-FN), which is considered as a new putative biomarker for BCSCs (NDY-1 cell) derived from human breast carcinosarcoma. We here review BCSC-targeted theranostics in vitro and in vivo by delivering siRNA or drug using the nanoparticles conjugated with a small peptide specific to EDB-FN.

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.

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.

Treatment of breast cancer with autophagy inhibitory microRNAs carried by AGO2-conjugated nanoparticles.

Nanoparticle based gene delivery systems holds great promise. Superparamagnetic iron oxide nanoparticles (SPIONs) are being heavily investigated due to good biocompatibility and added diagnostic potential, rendering such nanoparticles theranostic. Yet, commonly used cationic coatings for efficient delivery of such anionic cargos, results in significant toxicity limiting translation of the technology to the clinic. Here, we describe a highly biocompatible, small and non-cationic SPION-based theranostic nanoparticles as novel gene therapy agents. We propose for the first-time, the usage of the microRNA machinery RISC complex component Argonaute 2 (AGO2) protein as a microRNA stabilizing agent and a delivery vehicle. In this study, AGO2 protein-conjugated, anti-HER2 antibody-linked and fluorophore-tagged SPION nanoparticles were developed (SP-AH nanoparticles) and used as a carrier for an autophagy inhibitory microRNA, MIR376B. These functionalized nanoparticles selectively delivered an effective amount of the microRNA into HER2-positive breast cancer cell lines in vitro and in a xenograft nude mice model of breast cancer in vivo, and successfully blocked autophagy. Furthermore, combination of the chemotherapy agent cisplatin with MIR376B-loaded SP-AH nanoparticles increased the efficacy of the anti-cancer treatment both in vitro in cells and in vivo in the nude mice. Therefore, we propose that AGO2 protein conjugated SPIONs are a new class of theranostic nanoparticles and can be efficiently used as innovative, non-cationic, non-toxic gene therapy tools for targeted therapy of cancer.