Recent progress of the preparation and applications of superparamagnetic iron oxide（SPIO） clusters as magnetic resonance imaging（MRI） probes is reviewed with regard to their applications in labeling and tracking c...Recent progress of the preparation and applications of superparamagnetic iron oxide（SPIO） clusters as magnetic resonance imaging（MRI） probes is reviewed with regard to their applications in labeling and tracking cells in vivo, in diagnosis of cardiovascular diseases and tumors, and in drug delivery systems. Magnetic nanoparticles（NPs）, especially SPIO nanoparticles, have long been used as MRI contrast agents and as an advantageous nanoplatform for drug delivery,taking advantage of their unique magnetic properties and ability to function at the molecular and cellular levels. Due to advances in nanotechnology, various means to control SPIO NPs＇ size, composition, magnetization and relaxivity have been developed, as well as ways to usefully modify their surface. Recently, self-assembly of SPIO NP clusters in particulate carriers — such as polymeric micelles, vesicles, liposomes, and layer-by-layer（Lb L） capsules — have been widely studied for application as ultrasensitive MRI probes, owing to their remarkably high spin–spin（T2） relaxivity and convenience for further functionalization.展开更多
Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs ...Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs that primarily function as T2/T2*negative contrast agents,usSPIONs with core diameters below 5 nm can effectively shorten T1 relaxation times,producing bright signals in T1‐weighted images.This distinct behavior stems from their unique magnetic properties,including single‐domain configurations,surface spin canting,and rapid Néel relaxation dynamics,which are particularly enhanced at low magnetic field strengths.The biocompatibility of iron oxide,efficient renal clearance pathways,and versatility for surface functionalization offer potential advantages over gadolinium‐based agents,especially regarding safety concerns related to nephrogenic systemic fibrosis and gadolinium deposition.These nanoparticles show particular promise for applications in lowfield MRI,vascular imaging,targeted molecular imaging,and theranostic platforms.Although challenges remain in optimizing synthesis methods for consistent production of monodisperse usSPIONs with tailored surface chemistry,ongoing research continues to advance their potential for clinical translation.This review explores the mechanisms,synthesis approaches,applications,and future perspectives of usSPIONs as positive contrast agents in MRI.展开更多
Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in hu...Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.展开更多
Microflowers made of interconnected MnO2 nanosheets have been successfully synthesized in a microwave reactor through a hydrothermal reduction of KMnO4 with aqueous HCI at elevated temperatures in the presence of supe...Microflowers made of interconnected MnO2 nanosheets have been successfully synthesized in a microwave reactor through a hydrothermal reduction of KMnO4 with aqueous HCI at elevated temperatures in the presence of superparamagnetic Fe3O4SiO2 core-shell nanoparticles.Due to the chemical compatibility between SiO2 and MnO2,the heterogeneous reaction leads to the spontaneous encapsulation of the Fe3O4@SiO2 core-shell nanoparticles in the MnO2 microflowers.The resulting hybrid particles exhibit multiple properties including high surface area associated with the MnO2nanosheets and superparamagnetism originated from the Fe3O4@SiO2 core-shell nanoparticles.which are beneficial for applications requiring both high surface area and magnetic separation.展开更多
Superparamagnetic iron oxide nanoparticles （SPIONs） are one of the most versatile and safe nanoparticles in a wide variety of biomedical applications. In the past decades, considerable efforts have been made to inve...Superparamagnetic iron oxide nanoparticles （SPIONs） are one of the most versatile and safe nanoparticles in a wide variety of biomedical applications. In the past decades, considerable efforts have been made to investigate the potential adverse biological effects and safety issues associated with SPIONs, which is essential for the development of next-generation SPIONs and for continued progress in translational research. In this mini review, we summarize recent developments in toxicity studies on SPIONs, focusing on the relationship between the physicochemical properties of SPIONs and their induced toxic biological responses for a better toxicological understanding of SPIONs.展开更多
Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that...Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that are citrate coated for electrostatic stabilization.To determine their influence on murine blood-derived monocytes,which easily enter the injured central nervous system,we applied VSOP and carboxydextran-coated superparamagnetic iron oxide nanoparticles(Resovist).We assessed their impact on the viability,cytokine,and chemokine secretion,as well as iron uptake of murine blood-derived monocytes.We found that(1)the monocytes accumulated VSOP and Resovist,(2)this uptake seemed to be nanoparticle-and time-dependent,(3)the decrease of monocytes viability was treatment-related,(4)VSOP and Resovist incubation did not alter cytokine homeostasis,and(5)overall a 6-hour treatment with 0.75 mM VSOP-R1 was probably sufficient to effectively label monocytes for future experiments.Since homeostasis is not altered,it is safe to label blood-derived monocles with VSOP.VSOP labeled monocytes can be used to study injured central nervous system sites further,for example with drug-carrying VSOP.展开更多
Currently,we know that neuronal outgrowth during development and regeneration requires a complex interaction of intra-and extracellular molecules such as growth factors,neurotransmitters and extracellular matrix prote...Currently,we know that neuronal outgrowth during development and regeneration requires a complex interaction of intra-and extracellular molecules such as growth factors,neurotransmitters and extracellular matrix proteins（O’Donnell et al.,2009）.Furthermore,the discovery of a broad spectrum of growth-promoting cues has led to novel concepts for thera-peutic strategies.展开更多
Superparamagnetic iron oxide nanoparticles(SPIONs)have immeasurable potentials in many fields such as nanobiotechnology and biomedical engineering because of their superparamagnetic properties and small particle size....Superparamagnetic iron oxide nanoparticles(SPIONs)have immeasurable potentials in many fields such as nanobiotechnology and biomedical engineering because of their superparamagnetic properties and small particle size.This review introduces the methods for SPIONs synthesis,including co-precipitation,thermal decomposition,microemulsion and hydrothermal reaction,and surface modification of SPIONs with organometallic and inorganic metals,surface modification for targeted drug delivery,and the use of SPIONs as a contrast agent.In addition,this article also provides an overview of recent progress in SPIONs for the treatment of glioma,lung cancer and breast cancer.展开更多
In the late 1980s,superparamagnetic iron oxide nanoparticles（SPIO）moved into focus as contrast agents in magnetic resonance imaging（MRI）,due to their strong relaxivity and resulting higher resolution of images.At ...In the late 1980s,superparamagnetic iron oxide nanoparticles（SPIO）moved into focus as contrast agents in magnetic resonance imaging（MRI）,due to their strong relaxivity and resulting higher resolution of images.At the time,no one anticipated their high potential in basic research or for medical diagnostic andtreatment. Since then, SPIO have been evaluated notonly as spe- cific markers for MRI, but also for cell labeling and tracking （Li et al., 2013）.展开更多
Although iron oxide(Fe_(3)O_(4)) nanoparticles have broad application prospects as magnetic resonance imaging(MRI) contrast agent, their biocompatibility and biotoxicity still need to be improved. In this study, we pr...Although iron oxide(Fe_(3)O_(4)) nanoparticles have broad application prospects as magnetic resonance imaging(MRI) contrast agent, their biocompatibility and biotoxicity still need to be improved. In this study, we prepared Fe_(3)O_(4)@Angelica sinensis polysaccharide nanoparticles(Fe_(3)O_(4)@ASP NPs) with a 9 nm Fe_(3)O_(4) core and ASP as the coating material. The Fe_(3)O_(4)@ASP NPs are superparamagnetic, can be taken up by liver and spleen macrophages in the circulatory system in vivo, and are a good-biocompatibility and low-toxicity transverse relaxation time(T_(2)) and T_(2)-star(T_(2)^(*)) magnetic resonance imaging(MRI) contrast agent for the liver. The cytotoxicity assessment using HeLa cells and the pathological tests in mice validate that Fe_(3)O_(4)@ASP NPs have low toxicity and good biocompatibility in vivo, which can be attributed to the ASP as a natural polysaccharide with good biocompatibility and its function of protecting the liver. Fe_(3)O_(4)@ASP NPs are a potential new MRI contrast agent with high signal intensity in vivo.展开更多
Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures...Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures with narrow size distributions. At room temperature, the 8-nm ferrofluid shows superparamagnetic behaviour, whereas the others display hysteresis properties and the coercivity increases with the increasing particle size. The spin glass-like behaviour and cusps near 190K are observed on all ferrofluids according to the temperature variation of field-cooled （FC） and zero-field-cooled （ZFC） magnetization measurements. The cusps are found to be associated with the freezing point of the solvent. As a comparison, the ferrofluids are dried and the FC and ZFC magnetization curves of powdery samples are also investigated. It is found that the blocking temperatures for the powdery samples are higher than those for their corresponding ferrofluids. Moreover, the size dependent heating effect of the ferrofluids is also investigated in ac magnetic field with a frequency of 55 kHz and amplitude of 200 Oe.展开更多
Erectile dysfunction （ED） is a major complication of diabetes, and many diabetic men with ED are refractory to common ED therapies. Adipose tissue-derived stem cells （ADSCs） have been shown to improve erectile fun...Erectile dysfunction （ED） is a major complication of diabetes, and many diabetic men with ED are refractory to common ED therapies. Adipose tissue-derived stem cells （ADSCs） have been shown to improve erectile function in diabetic animal models. However, inadequate cell homing to damaged sites has limited their efficacy. Therefore, we explored the effect of ADSCs labeled with superparamagnetic iron oxide nanoparticles （SPIONs） on improving the erectile function of streptozotocin-induced diabetic rats with an external magnetic field. We found that SPIONs effectively incorporated into ADSCs and did not exert any negative effects on stem cell properties. Magnetic targeting of ADSCs contributed to long-term cell retention in the corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. In addition, the paracrine effect of ADSCs appeared to play the major role in functional and structural recovery. Accordingly, magnetic field-guided ADSC therapy is an effective approach for diabetes-associated ED therapy.展开更多
Age-related macular degeneration（AMD） is the leading cause of vision loss in the elderly throughout the world. Treatment of AMD utilizing retinal pigment epithelium（RPE） transplantation represents a promising ther...Age-related macular degeneration（AMD） is the leading cause of vision loss in the elderly throughout the world. Treatment of AMD utilizing retinal pigment epithelium（RPE） transplantation represents a promising therapy. However, simplex RPE transplantation can only replace the diseased RPE cells, but has no abilities to stop the development of AMD. It has been indicated that oxidization triggers the development of AMD by inducing the dysfunction and degeneration of RPE cells, which results in the upregulation of local monocyte chemotactic protein-1（MCP-1） expression. MCP-1 induces macrophage recruiment which triggers local inflammation. As a result, the expression of vascular endothelial growth factor（VEGF） is upregulated by MCP-1mediated inflammation and results in the formation of choroidal neovascularization（CNV）. We accordingly propose a targeted therapy of AMD by subretinal transplanting the compound of RPE cell, MCP-1 antibody, and VEGF antibody and using a magnetic system to guide RPE cell compounds conjugated with superparamagnetic iron oxide nanoparticles（SPIONs）. Furthermore, SPION-labelled RPE cells can be tracked and detected in vivo by non-invasive magnetic resonance imaging（MRI）. This novel RPE cell transplantation methodology seems very promising to provide a new therapeutic approach for the treatment of AMD.展开更多
Background:In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies.This study invest...Background:In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies.This study investigated tracking of human Wharton’s jelly stem cells(hWJSCs)seeded onto an acellular dermal matrix(ADM)and labeled with superparamagnetic iron oxide nanoparti-cles(SPIONs)by magnetic resonance imaging(MRI)in burn injury.Method:The hWJSCs were characterized and assessed for growth kinetics.A total of 30 rats were enrolled in three equal groups.Group 1 underwent scald burn injury left without treatment,the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an ADM.Tensile strength was evaluated before and after interventions,real time PCR assessed apoptosis,and Prussian blue staining,scanning electron microscopy(SEM)and MRI were used for the tracking of labeled cells.Results:The hWJSCs exhibited mesenchymal stem cell properties.Population doubling time was 40.1 hours.SPIONs did not show any toxic effect.The hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene expression.Internalization of SPIONs within hWJSCs was confirmed by Prussian blue staining,SEM and MRI until day 21.There was a significant difference between the Young’s moduli of normal skin and the group receiving hWJSCs seeded onto an ADM.Histological observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in vivo.Conclusions:This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.展开更多
hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug d...hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug delivery systems can use a specific magnetic field to attract the drug to the target site,increasing the drug concentration.In this study,we found that the double-labeling using superparamagnetic iron oxide nanoparticle and poly-L-lysine(SPIO-PLL)of bone marrow-derived mesenchymal stem cells had no effect on cell survival but decreased cell proliferation 48 hours after labeling.Rat models of hypoxic-ischemic brain injury were established by ligating the left common carotid artery.One day after modeling,intraventricular and caudal vein injections of 1×105 SPIO-PLL-labeled bone marrow-derived mesenchymal stem cells were performed.Twenty-four hours after the intraventricular injection,magnets were fixed to the left side of the rats’heads for 2 hours.Intravoxel incoherent motion magnetic resonance imaging revealed that the perfusion fraction and the diffusion coefficient of rat brain tissue were significantly increased in rats treated with SPIO-PLL-labeled cells through intraventricular injection combined with magnetic guidance,compared with those treated with SPIO-PLL-labeled cells through intraventricular or tail vein injections without magnetic guidance.Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining revealed that in rats treated with SPIO-PLL-labeled cells through intraventricular injection under magnetic guidance,cerebral edema was alleviated,and apoptosis was decreased.These findings suggest that targeted magnetic guidance can be used to improve the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for hypoxic-ischemic brain injury.This study was approved by the Animal Care and Use Committee of The Second Hospital of Dalian Medical University,China(approval No.2016-060)on March 2,2016.展开更多
A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed...A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed from the test results of X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transimission electron microscopy （HRTEM）, hysteresis loop, and photoluminescence （PL） spectrum, these nanocomposites exhibit superparamagnetic and photoluminescent properties.展开更多
A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmissi...A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.展开更多
On the growing clinical demands,superparamagnetic iron oxide nanoparticles(SPIONs)have a vital role due to their infinite physical and chemical properties at the nanoscale.The researchers have started to focus more on...On the growing clinical demands,superparamagnetic iron oxide nanoparticles(SPIONs)have a vital role due to their infinite physical and chemical properties at the nanoscale.The researchers have started to focus more on the magnetite nanoparticle applications with unique shape and size in various filed such as biomedicine,food and environment to synthesize Fe_(3)O_(4)NP.Here we synthesized SPIONs-Fe_(3)O_(4)NP successfully by co-precipitation technique.The prepared nanoparticles were characterized using suitable analytical tools for structural,morphological,elemental,optical and thermogravimetric analysis.Moreover,the genotoxicity and hemolysis assay test has been carried out to estimate the toxicity of SPIONs-Fe_(3)O_(4)NP at various concentrations.The results found that 25 μg/mL concentration of SPIONs-Fe_(3)O_(4)NP shows good hemocompatibility than other concentrations.The genotoxicity assay was examined in Allium cepa(onion root tips)for chromosomal aberration.Hence,the present study discusses the synthesis characterization,assessing the genotoxicity and hemocompatibility potential for the synthesized Fe_(3)O_(4)NPs.展开更多
Superparamagnetic iron oxide nanoparticles(SPIONs),due to their controllable sizes,relatively long in vivo half-life and limited agglomeration,are ideal for biomedical applications such as magnetic labeling,hypertherm...Superparamagnetic iron oxide nanoparticles(SPIONs),due to their controllable sizes,relatively long in vivo half-life and limited agglomeration,are ideal for biomedical applications such as magnetic labeling,hyperthermia cancer treatment,targeted drug delivery and for magnetic resonance imaging(MRI)as contrast enhancement agents.In order to understand how SPIONs interact with cells and cellular membranes it would be of interest to characterize individual SPIONs at the nanoscale in physiologically relevant conditions without labeling them.We demonstrate that Magnetic Force Microscopy(MFM)can be used to image SPIONs in air as well as in liquid.The magnetic properties of bare and SiO2 coated SPIONs are compared using MFM.We report that surface modification using(3-mercaptopropyl)-trimethoxysilane significantly improves adsorption and distribution of SPIONs on gold surfaces.To obtain proof of principle that SPIONS can be imaged with MFM inside the cell we imaged SPIONs buried in thin polymer films(polystyrene(PS)and poly methyl-methacrylate(PMMA)).This opens the possibility of visualizing SPIONs inside the cell without any labeling or modifications and present MFM as a potential magnetic analogue for fluorescence microscopy.The results of these studies may have a valuable impact for characterization and further development of biomedical applications of SPIONs and other magnetic nanoparticles.展开更多
Over the past few decades,engineered,(super)paramagnetic nanoparticles have drawn extensive research attention for a broad range of applications based on their tunable size and shape,surface chemistries,and magnetic p...Over the past few decades,engineered,(super)paramagnetic nanoparticles have drawn extensive research attention for a broad range of applications based on their tunable size and shape,surface chemistries,and magnetic properties.This review summaries our recent work on the synthesis,surface modification,and environmental application of(super)paramagnetic nanoparticles.By utilizing high-temperature thermo-decomposition methods,first,we have broadly demonstrated the synthesis of highly monodispersed,(super)paramagnetic nanoparticles,via the pyrolysis of metal carboxylate salts in an organic phase.Highly uniform magnetic nanoparticles with various size,composition,and shape can be precisely tuned by controlled reaction parameters,such as the initial precursors,heating rate,final reaction temperature,reaction time,and the additives.These materials can be further rendered water stable via functionalization with surface mono/bi-layer coating structure using a series of tunable ionic/non-ionic surfactants.Finally,we have demonstrated platform potential of these materials for heavy metal ions sensing,sorption,and separation from the aqueous phase.展开更多
基金Project supported by the National Key Basic Research Program of China(Grant No.2013CB933903)the National Natural Science Foundation of China(Grant Nos.20974065+2 种基金51173117and 50830107)the Scientific Research Start-up Fund of Kunming University of Science and Technology(Grant No.KKSY201305089)
文摘Recent progress of the preparation and applications of superparamagnetic iron oxide（SPIO） clusters as magnetic resonance imaging（MRI） probes is reviewed with regard to their applications in labeling and tracking cells in vivo, in diagnosis of cardiovascular diseases and tumors, and in drug delivery systems. Magnetic nanoparticles（NPs）, especially SPIO nanoparticles, have long been used as MRI contrast agents and as an advantageous nanoplatform for drug delivery,taking advantage of their unique magnetic properties and ability to function at the molecular and cellular levels. Due to advances in nanotechnology, various means to control SPIO NPs＇ size, composition, magnetization and relaxivity have been developed, as well as ways to usefully modify their surface. Recently, self-assembly of SPIO NP clusters in particulate carriers — such as polymeric micelles, vesicles, liposomes, and layer-by-layer（Lb L） capsules — have been widely studied for application as ultrasensitive MRI probes, owing to their remarkably high spin–spin（T2） relaxivity and convenience for further functionalization.
文摘Ultrasmall superparamagnetic iron oxide nanoparticles(usSPIONs)are promising alternatives to gadolinium‐based contrast agents for positive contrast enhancement in magnetic resonance imaging(MRI).Unlike larger SPIONs that primarily function as T2/T2*negative contrast agents,usSPIONs with core diameters below 5 nm can effectively shorten T1 relaxation times,producing bright signals in T1‐weighted images.This distinct behavior stems from their unique magnetic properties,including single‐domain configurations,surface spin canting,and rapid Néel relaxation dynamics,which are particularly enhanced at low magnetic field strengths.The biocompatibility of iron oxide,efficient renal clearance pathways,and versatility for surface functionalization offer potential advantages over gadolinium‐based agents,especially regarding safety concerns related to nephrogenic systemic fibrosis and gadolinium deposition.These nanoparticles show particular promise for applications in lowfield MRI,vascular imaging,targeted molecular imaging,and theranostic platforms.Although challenges remain in optimizing synthesis methods for consistent production of monodisperse usSPIONs with tailored surface chemistry,ongoing research continues to advance their potential for clinical translation.This review explores the mechanisms,synthesis approaches,applications,and future perspectives of usSPIONs as positive contrast agents in MRI.
基金supported by the National Key R&D Program of China,Nos.2017YFA0104302(to NG and XM)and 2017YFA0104304(to BW and ZZ)
文摘Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.
基金supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,under Contract No.DE-AC02-06CH11357
文摘Microflowers made of interconnected MnO2 nanosheets have been successfully synthesized in a microwave reactor through a hydrothermal reduction of KMnO4 with aqueous HCI at elevated temperatures in the presence of superparamagnetic Fe3O4SiO2 core-shell nanoparticles.Due to the chemical compatibility between SiO2 and MnO2,the heterogeneous reaction leads to the spontaneous encapsulation of the Fe3O4@SiO2 core-shell nanoparticles in the MnO2 microflowers.The resulting hybrid particles exhibit multiple properties including high surface area associated with the MnO2nanosheets and superparamagnetism originated from the Fe3O4@SiO2 core-shell nanoparticles.which are beneficial for applications requiring both high surface area and magnetic separation.
基金Project supported by the Major State Basic Research Development Program of China(Grant Nos.2013CB733802 and 2014CB744503)the National Natural Science Foundation of China(Grant Nos.81101101 and 51273165)+1 种基金the Key Project of Chinese Ministry of Education(Grant No.212149)the Fundamental Research Funds for the Central Universities,China(Grant Nos.2013121039 and ZK1002)
文摘Superparamagnetic iron oxide nanoparticles （SPIONs） are one of the most versatile and safe nanoparticles in a wide variety of biomedical applications. In the past decades, considerable efforts have been made to investigate the potential adverse biological effects and safety issues associated with SPIONs, which is essential for the development of next-generation SPIONs and for continued progress in translational research. In this mini review, we summarize recent developments in toxicity studies on SPIONs, focusing on the relationship between the physicochemical properties of SPIONs and their induced toxic biological responses for a better toxicological understanding of SPIONs.
基金supported by Deutsche Forschungsgemeinschaft(DFG)grant Klinische Forschergruppe(KFO)213(to JG).
文摘Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that are citrate coated for electrostatic stabilization.To determine their influence on murine blood-derived monocytes,which easily enter the injured central nervous system,we applied VSOP and carboxydextran-coated superparamagnetic iron oxide nanoparticles(Resovist).We assessed their impact on the viability,cytokine,and chemokine secretion,as well as iron uptake of murine blood-derived monocytes.We found that(1)the monocytes accumulated VSOP and Resovist,(2)this uptake seemed to be nanoparticle-and time-dependent,(3)the decrease of monocytes viability was treatment-related,(4)VSOP and Resovist incubation did not alter cytokine homeostasis,and(5)overall a 6-hour treatment with 0.75 mM VSOP-R1 was probably sufficient to effectively label monocytes for future experiments.Since homeostasis is not altered,it is safe to label blood-derived monocles with VSOP.VSOP labeled monocytes can be used to study injured central nervous system sites further,for example with drug-carrying VSOP.
文摘Currently,we know that neuronal outgrowth during development and regeneration requires a complex interaction of intra-and extracellular molecules such as growth factors,neurotransmitters and extracellular matrix proteins（O’Donnell et al.,2009）.Furthermore,the discovery of a broad spectrum of growth-promoting cues has led to novel concepts for thera-peutic strategies.
基金Supported by National Natural Science Foundation of China(32060228)。
文摘Superparamagnetic iron oxide nanoparticles(SPIONs)have immeasurable potentials in many fields such as nanobiotechnology and biomedical engineering because of their superparamagnetic properties and small particle size.This review introduces the methods for SPIONs synthesis,including co-precipitation,thermal decomposition,microemulsion and hydrothermal reaction,and surface modification of SPIONs with organometallic and inorganic metals,surface modification for targeted drug delivery,and the use of SPIONs as a contrast agent.In addition,this article also provides an overview of recent progress in SPIONs for the treatment of glioma,lung cancer and breast cancer.
基金supported by deutsche Forschungsgemeinschaft Grant Klinische Forschungsgruppe 213 to JG
文摘In the late 1980s,superparamagnetic iron oxide nanoparticles（SPIO）moved into focus as contrast agents in magnetic resonance imaging（MRI）,due to their strong relaxivity and resulting higher resolution of images.At the time,no one anticipated their high potential in basic research or for medical diagnostic andtreatment. Since then, SPIO have been evaluated notonly as spe- cific markers for MRI, but also for cell labeling and tracking （Li et al., 2013）.
基金financially supported by the National Key Research and Development Program of China(No.2019YFB2005801)the National Natural Science Foundation of China(Nos.51671019,51731003,51971024,51927802 and 51971023)+1 种基金Beijing Natural Science Foundation Key Program(No.Z190007)Fundamental Research Funds for the Central Universities(No.FRF-MP-19-004)。
文摘Although iron oxide(Fe_(3)O_(4)) nanoparticles have broad application prospects as magnetic resonance imaging(MRI) contrast agent, their biocompatibility and biotoxicity still need to be improved. In this study, we prepared Fe_(3)O_(4)@Angelica sinensis polysaccharide nanoparticles(Fe_(3)O_(4)@ASP NPs) with a 9 nm Fe_(3)O_(4) core and ASP as the coating material. The Fe_(3)O_(4)@ASP NPs are superparamagnetic, can be taken up by liver and spleen macrophages in the circulatory system in vivo, and are a good-biocompatibility and low-toxicity transverse relaxation time(T_(2)) and T_(2)-star(T_(2)^(*)) magnetic resonance imaging(MRI) contrast agent for the liver. The cytotoxicity assessment using HeLa cells and the pathological tests in mice validate that Fe_(3)O_(4)@ASP NPs have low toxicity and good biocompatibility in vivo, which can be attributed to the ASP as a natural polysaccharide with good biocompatibility and its function of protecting the liver. Fe_(3)O_(4)@ASP NPs are a potential new MRI contrast agent with high signal intensity in vivo.
文摘Fe3O4 ferrofluids containing monodisperse Fe3O4 nanoparticles with different diameters of 8, 12, 16 and 18nm are prepared by using high-temperature solution phase reaction. The particles have single crystal structures with narrow size distributions. At room temperature, the 8-nm ferrofluid shows superparamagnetic behaviour, whereas the others display hysteresis properties and the coercivity increases with the increasing particle size. The spin glass-like behaviour and cusps near 190K are observed on all ferrofluids according to the temperature variation of field-cooled （FC） and zero-field-cooled （ZFC） magnetization measurements. The cusps are found to be associated with the freezing point of the solvent. As a comparison, the ferrofluids are dried and the FC and ZFC magnetization curves of powdery samples are also investigated. It is found that the blocking temperatures for the powdery samples are higher than those for their corresponding ferrofluids. Moreover, the size dependent heating effect of the ferrofluids is also investigated in ac magnetic field with a frequency of 55 kHz and amplitude of 200 Oe.
文摘Erectile dysfunction （ED） is a major complication of diabetes, and many diabetic men with ED are refractory to common ED therapies. Adipose tissue-derived stem cells （ADSCs） have been shown to improve erectile function in diabetic animal models. However, inadequate cell homing to damaged sites has limited their efficacy. Therefore, we explored the effect of ADSCs labeled with superparamagnetic iron oxide nanoparticles （SPIONs） on improving the erectile function of streptozotocin-induced diabetic rats with an external magnetic field. We found that SPIONs effectively incorporated into ADSCs and did not exert any negative effects on stem cell properties. Magnetic targeting of ADSCs contributed to long-term cell retention in the corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. In addition, the paracrine effect of ADSCs appeared to play the major role in functional and structural recovery. Accordingly, magnetic field-guided ADSC therapy is an effective approach for diabetes-associated ED therapy.
基金Supported by the National Natural Science Foundation of China(No.81100670)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry of China
文摘Age-related macular degeneration（AMD） is the leading cause of vision loss in the elderly throughout the world. Treatment of AMD utilizing retinal pigment epithelium（RPE） transplantation represents a promising therapy. However, simplex RPE transplantation can only replace the diseased RPE cells, but has no abilities to stop the development of AMD. It has been indicated that oxidization triggers the development of AMD by inducing the dysfunction and degeneration of RPE cells, which results in the upregulation of local monocyte chemotactic protein-1（MCP-1） expression. MCP-1 induces macrophage recruiment which triggers local inflammation. As a result, the expression of vascular endothelial growth factor（VEGF） is upregulated by MCP-1mediated inflammation and results in the formation of choroidal neovascularization（CNV）. We accordingly propose a targeted therapy of AMD by subretinal transplanting the compound of RPE cell, MCP-1 antibody, and VEGF antibody and using a magnetic system to guide RPE cell compounds conjugated with superparamagnetic iron oxide nanoparticles（SPIONs）. Furthermore, SPION-labelled RPE cells can be tracked and detected in vivo by non-invasive magnetic resonance imaging（MRI）. This novel RPE cell transplantation methodology seems very promising to provide a new therapeutic approach for the treatment of AMD.
文摘Background:In vivo cell tracking after transplantation in regenerative medicine remains an unmet challenge and limits current understanding of the wound healing mechanism through cell-based therapies.This study investigated tracking of human Wharton’s jelly stem cells(hWJSCs)seeded onto an acellular dermal matrix(ADM)and labeled with superparamagnetic iron oxide nanoparti-cles(SPIONs)by magnetic resonance imaging(MRI)in burn injury.Method:The hWJSCs were characterized and assessed for growth kinetics.A total of 30 rats were enrolled in three equal groups.Group 1 underwent scald burn injury left without treatment,the group 2 was treated by an ADM that was prepared from cosmetic surgery skin samples and the group 3 received hWJSCs labeled with SPIONs seeded onto an ADM.Tensile strength was evaluated before and after interventions,real time PCR assessed apoptosis,and Prussian blue staining,scanning electron microscopy(SEM)and MRI were used for the tracking of labeled cells.Results:The hWJSCs exhibited mesenchymal stem cell properties.Population doubling time was 40.1 hours.SPIONs did not show any toxic effect.The hWJSCs seeded onto an ADM decreased Bax and increased Bcl-2 gene expression.Internalization of SPIONs within hWJSCs was confirmed by Prussian blue staining,SEM and MRI until day 21.There was a significant difference between the Young’s moduli of normal skin and the group receiving hWJSCs seeded onto an ADM.Histological observations and SEM imaging confirmed that MRI is an accurate method to track SPION-labeled hWJSCs in vivo.Conclusions:This study showed that SPION labeling coupled with MRI can be used to further understand the fate of stem cells after transplantation in a burn model.
文摘hypoxicischemic brain injury;however,the therapeutic efficacy of bone marrow-derived mesenchymal stem cells largely depends on the number of cells that are successfully transferred to the target.Magnet-targeted drug delivery systems can use a specific magnetic field to attract the drug to the target site,increasing the drug concentration.In this study,we found that the double-labeling using superparamagnetic iron oxide nanoparticle and poly-L-lysine(SPIO-PLL)of bone marrow-derived mesenchymal stem cells had no effect on cell survival but decreased cell proliferation 48 hours after labeling.Rat models of hypoxic-ischemic brain injury were established by ligating the left common carotid artery.One day after modeling,intraventricular and caudal vein injections of 1×105 SPIO-PLL-labeled bone marrow-derived mesenchymal stem cells were performed.Twenty-four hours after the intraventricular injection,magnets were fixed to the left side of the rats’heads for 2 hours.Intravoxel incoherent motion magnetic resonance imaging revealed that the perfusion fraction and the diffusion coefficient of rat brain tissue were significantly increased in rats treated with SPIO-PLL-labeled cells through intraventricular injection combined with magnetic guidance,compared with those treated with SPIO-PLL-labeled cells through intraventricular or tail vein injections without magnetic guidance.Hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining revealed that in rats treated with SPIO-PLL-labeled cells through intraventricular injection under magnetic guidance,cerebral edema was alleviated,and apoptosis was decreased.These findings suggest that targeted magnetic guidance can be used to improve the therapeutic efficacy of bone marrow-derived mesenchymal stem cell transplantation for hypoxic-ischemic brain injury.This study was approved by the Animal Care and Use Committee of The Second Hospital of Dalian Medical University,China(approval No.2016-060)on March 2,2016.
基金Project supported by the National Natural Science Foundation of China (Grant No.50872129)
文摘A luminescent superparamagnetic nanocomposite with an Fe3O4 SiO2-CdS structure is synthesised. Coated with a silica shell, Fe3O4 nanoparticles and CdS quantum dots （QDs） are successfully assembled together. Analysed from the test results of X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high resolution transimission electron microscopy （HRTEM）, hysteresis loop, and photoluminescence （PL） spectrum, these nanocomposites exhibit superparamagnetic and photoluminescent properties.
基金supported by the Ho Chi Minh City Department of Science and Technology, Viet Nam
文摘A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.
基金Funding was provided by the RUSA 2.0-BEICH Government of India and Department of Science and Technology(DST)PURSE-Phase-Ⅱ.
文摘On the growing clinical demands,superparamagnetic iron oxide nanoparticles(SPIONs)have a vital role due to their infinite physical and chemical properties at the nanoscale.The researchers have started to focus more on the magnetite nanoparticle applications with unique shape and size in various filed such as biomedicine,food and environment to synthesize Fe_(3)O_(4)NP.Here we synthesized SPIONs-Fe_(3)O_(4)NP successfully by co-precipitation technique.The prepared nanoparticles were characterized using suitable analytical tools for structural,morphological,elemental,optical and thermogravimetric analysis.Moreover,the genotoxicity and hemolysis assay test has been carried out to estimate the toxicity of SPIONs-Fe_(3)O_(4)NP at various concentrations.The results found that 25 μg/mL concentration of SPIONs-Fe_(3)O_(4)NP shows good hemocompatibility than other concentrations.The genotoxicity assay was examined in Allium cepa(onion root tips)for chromosomal aberration.Hence,the present study discusses the synthesis characterization,assessing the genotoxicity and hemocompatibility potential for the synthesized Fe_(3)O_(4)NPs.
基金funded by Natural Science and Engineering Council of Canada(NSERC).
文摘Superparamagnetic iron oxide nanoparticles(SPIONs),due to their controllable sizes,relatively long in vivo half-life and limited agglomeration,are ideal for biomedical applications such as magnetic labeling,hyperthermia cancer treatment,targeted drug delivery and for magnetic resonance imaging(MRI)as contrast enhancement agents.In order to understand how SPIONs interact with cells and cellular membranes it would be of interest to characterize individual SPIONs at the nanoscale in physiologically relevant conditions without labeling them.We demonstrate that Magnetic Force Microscopy(MFM)can be used to image SPIONs in air as well as in liquid.The magnetic properties of bare and SiO2 coated SPIONs are compared using MFM.We report that surface modification using(3-mercaptopropyl)-trimethoxysilane significantly improves adsorption and distribution of SPIONs on gold surfaces.To obtain proof of principle that SPIONS can be imaged with MFM inside the cell we imaged SPIONs buried in thin polymer films(polystyrene(PS)and poly methyl-methacrylate(PMMA)).This opens the possibility of visualizing SPIONs inside the cell without any labeling or modifications and present MFM as a potential magnetic analogue for fluorescence microscopy.The results of these studies may have a valuable impact for characterization and further development of biomedical applications of SPIONs and other magnetic nanoparticles.
基金supported by American Chemical Society's Petroleum Research Fund(#52640-DNI10)the US National Science Foundation(CBET,#1236653 and#1437820)US Army Corps of Engineers(W912HZ-13-2-0009-P00001).
文摘Over the past few decades,engineered,(super)paramagnetic nanoparticles have drawn extensive research attention for a broad range of applications based on their tunable size and shape,surface chemistries,and magnetic properties.This review summaries our recent work on the synthesis,surface modification,and environmental application of(super)paramagnetic nanoparticles.By utilizing high-temperature thermo-decomposition methods,first,we have broadly demonstrated the synthesis of highly monodispersed,(super)paramagnetic nanoparticles,via the pyrolysis of metal carboxylate salts in an organic phase.Highly uniform magnetic nanoparticles with various size,composition,and shape can be precisely tuned by controlled reaction parameters,such as the initial precursors,heating rate,final reaction temperature,reaction time,and the additives.These materials can be further rendered water stable via functionalization with surface mono/bi-layer coating structure using a series of tunable ionic/non-ionic surfactants.Finally,we have demonstrated platform potential of these materials for heavy metal ions sensing,sorption,and separation from the aqueous phase.
