共查询到20条相似文献，搜索用时 15 毫秒
1.
Lucia Cardo Lydia Martínez-Parra Michele Cesco Begoña M. Echeverría-Beistegui Marta Martínez-Moro Natalia Herrero-Álvarez Marta-Beraza Cabrerizo Susana Carregal-Romero Pedro Ramos-Cabrer Jesús Ruiz-Cabello Maurizio Prato 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(31):2206442
Carbon Dots (CDs) are luminescent quasi-spherical nanoparticles, possessing water solubility, high biocompatibility, and tunable chemical and physical properties for a wide range of applications, including nanomedicine and theranostics. The evaluation of new purification criteria, useful to achieve more reliable CDs, free from the interference of artifacts, is currently an object of debate in the field. Here, new CDs doped with gadolinium (Gd (III)), named Gd@CNDs, are presented as multifunctional probes for Magnetic Resonance Imaging (MRI). This new system is a case of study, to evaluate and/or combine different purification strategies, as a crucial approach to generate CDs with a better performance. Indeed, these new amorphous Gd@CNDs display good homogeneity, and they are free from emissive side products. Gd@CNDs (7–10 nm) contain 7% of Gd (III) w/w, display suitable and stable longitudinal relaxivity (r1) and with emissive behavior, therefore potentially useful for both MR and fluorescence imaging. They show good biocompatibility in both cellular and in vivo studies, cell permeability, and the ability to generate contrast in cellular pellets. Finally, MRI recording T1-weighted images on mice after intravenous injection of Gd@CNDs, show signal enhancement in the liver, spleen, and kidney 30 min postinjection. 相似文献
2.
Albert Moussaron Sandip Vibhute Andrea Bianchi Serhat Gündüz Shady Kotb Lucie Sancey Vincent Motto‐Ros Silvia Rizzitelli Yannick Crémillieux Francois Lux Nikos K. Logothetis Olivier Tillement Goran Angelovski 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(37):4900-4909
The preparation of ultrasmall and rigid platforms (USRPs) that are covalently coupled to macrocycle‐based, calcium‐responsive/smart contrast agents (SCAs), and the initial in vitro and in vivo validation of the resulting nanosized probes (SCA‐USRPs) by means of magnetic resonance imaging (MRI) is reported. The synthetic procedure is robust, allowing preparation of the SCA‐USRPs on a multigram scale. The resulting platforms display the desired MRI activity—i.e., longitudinal relaxivity increases almost twice at 7 T magnetic field strength upon saturation with Ca2+. Cell viability is probed with the MTT assay using HEK‐293 cells, which show good tolerance for lower contrast agent concentrations over longer periods of time. On intravenous administration of SCA‐USRPs in living mice, MRI studies indicate their rapid accumulation in the renal pelvis and parenchyma. Importantly, the MRI signal increases in both kidney compartments when CaCl2 is also administrated. Laser‐induced breakdown spectroscopy experiments confirm accumulation of SCA‐USRPs in the renal cortex. To the best of our knowledge, these are the first studies which demonstrate calcium‐sensitive MRI signal changes in vivo. Continuing contrast agent and MRI protocol optimizations should lead to wider application of these responsive probes and development of superior functional methods for monitoring calcium‐dependent physiological and pathological processes in a dynamic manner. 相似文献
3.
Mengxing Wei Lulu Wang Yanfang Wang Tong Zhang Chenchen Wang Chengfan Wu Changlin Tian Gaolin Liang Yue Yuan 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(29):2300015
Magnetic resonance imaging (MRI) is a superior and noninvasive imaging technique with unlimited tissue penetration depth and superb spatiotemporal resolution, however, using intracellular self-assembly of Gd-containing nanoparticles to enhance the T2-weighted MR contrast of cancer cells in vivo for precise tumor MRI is rarely reported. The lysosomal cysteine protease cathepsin B (CTSB) is regarded as an attractive biomarker for the early diagnosis of cancers and metastasis. Herein, taking advantage of a biocompatible condensation reaction, a “smart” Gd-based CTSB-responsive small molecular contrast agent VC-Gd-CBT is developed, which can self-assemble into large intracellular Gd-containing nanoparticles by glutathione reduction and CTSB cleavage to enhance the T2-weighted MR contrast of CTSB-overexpressing MDA-MB-231 cells at 9.4 T. In vivo T2-weighted MRI studies using MDA-MB-231 murine xenografts show that the T2-weighted MR contrast change of tumors in VC-Gd-CBT-injected mice is distinctly larger than the mice injected with the commercial agent gadopentetate dimeglumine, or co-injected with CTSB inhibitor and VC-Gd-CBT, indicating that the accumulation of self-assembled Gd-containing nanoparticles at tumor sites effectively enhances the T2-weighted MR tumor imaging. Hence, this CTSB-targeted small molecule VC-Gd-CBT has the potential to be employed as a T2 contrast agent for the clinical diagnosis of cancers at an early stage. 相似文献
4.
Zheyu Shen Wenpei Fan Zhen Yang Yijing Liu Vladimir I. Bregadze Swadhin K. Mandal Bryant C. Yung Lisen Lin Ting Liu Wei Tang Lingling Shan Yuan Liu Shoujun Zhu Sheng Wang Weijing Yang L. Henry Bryant Duong T. Nguyen Aiguo Wu Xiaoyuan Chen 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(41)
Gd chelates have occupied most of the market of magnetic resonance imaging (MRI) contrast agents for decades. However, there have been some problems (nephrotoxicity, non‐specificity, and low r1) that limit their applications. Herein, a wet‐chemical method is proposed for facile synthesis of poly(acrylic acid) (PAA) stabilized exceedingly small gadolinium oxide nanoparticles (ES‐GON‐PAA) with an excellent water dispersibility and a size smaller than 2.0 nm, which is a powerful T1‐weighted MRI contrast agent for diagnosis of diseases due to its remarkable relaxivities (r1 = 70.2 ± 1.8 mM?1 s?1, and r2/r1 = 1.02 ± 0.03, at 1.5 T). The r1 is much higher and the r2/r1 is lower than that of the commercial Gd chelates and reported gadolinium oxide nanoparticles (GONs). Further ES‐GON‐PAA is developed with conjugation of RGD2 (RGD dimer) (i.e., ES‐GON‐PAA@RGD2) for T1‐weighted MRI of tumors that overexpress RGD receptors (i.e., integrin αvβ3). The maximum signal enhancement (ΔSNR) for T1‐weighted MRI of tumors reaches up to 372 ± 56% at 2 h post‐injection of ES‐GON‐PAA@RGD2, which is much higher than commercial Gd‐chelates (<80%). Due to the high biocompatibility and high tumor accumulation, ES‐GON‐PAA@RGD2 with remarkable relaxivities is a promising and powerful T1‐weighted MRI contrast agent. 相似文献
5.
Hsiao JK Tsai CP Chung TH Hung Y Yao M Liu HM Mou CY Yang CS Chen YC Huang DM 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(9):1445-1452
The progress of using gadolinium (Gd)-based nanoparticles in cellular tracking lags behind that of superparamagnetic iron oxide (SPIO) nanoparticles in magnetic resonance imaging (MRI). Here, dual functional Gd-fluorescein isothiocyanate mesoporous silica nanoparticles (Gd-Dye@MSN) that possess green fluorescence and paramagnetism are developed in order to evaluate their potential as effective T1-enhancing trackers for human mesenchymal stem cells (hMSCs). hMSCs are labeled efficiently with Gd-Dye@MSN via endocytosis. Labeled hMSCs are unaffected in their viability, proliferation, and differentiation capacities into adipocytes, osteocytes, and chondrocytes, which can still be readily MRI detected. Imaging, with a clinical 1.5-T MRI system and a low incubation dosage of Gd, low detection cell numbers, and short incubation times is demonstrated on both loaded cells and hMSC-injected mouse brains. This study shows that the advantages of biocompatibility, durability, high internalizing efficiency, and pore architecture make MSNs an ideal vector of T1-agent for stem-cell tracking with MRI. 相似文献
6.
Srivastava S Awasthi R Tripathi D Rai MK Agarwal V Agrawal V Gajbhiye NS Gupta RK 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(7):1099-1109
A novel and facile approach is developed to synthesize a magnetic nanoparticle (iron oxide)-doped carbogenic nanocomposite (IO-CNC) for magnetic resonance (MR)/fluorescence imaging applications. IO-CNC is synthesized by thermal decomposition of organic precursors in the presence of Fe(3) O(4) nanoparticles with an average size of 6 nm. IO-CNC shows wavelength-tunable fluorescence properties with high quantum yield. Magnetic studies confirm the superparamagnetic nature of IO-CNC at room temperature. IO-CNC shows MR contrast behavior by affecting the proton relaxation phenomena. The measured longitudinal (r(1) ) and transverse (r(2) ) relaxivity values are 4.52 and 34.75 mM(-1) s(-1) , respectively. No apparent cytotoxicity is observed and the nanocomposite shows a biocompatible nature. In vivo MR studies show both T(1) and T(2) * contrast behavior of the nanocomposite. Fluorescence imaging indicates selective uptake of IO-CNC by macrophages in spleen. 相似文献
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Erwin Peng Eugene Shi Guang Choo Prashant Chandrasekharan Chang‐Tong Yang Jun Ding Kai‐Hsiang Chuang Jun Min Xue 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(23):3620-3630
In this study, MnFe2O4 nanoparticle (MFNP)‐decorated graphene oxide nanocomposites (MGONCs) are prepared through a simple mini‐emulsion and solvent evaporation process. It is demonstrated that the loading of magnetic nanocrystals can be tuned by varying the ratio of graphene oxide/magnetic nanoparticles. On top of that, the hydrodynamic size range of the obtained nanocomposites can be optimized by varying the sonication time during the emulsion process. By fine‐tuning the sonication time, MGONCs as small as 56.8 ± 1.1 nm, 55.0 ± 0.6 nm and 56.2 ± 0.4 nm loaded with 6 nm, 11 nm, and 14 nm MFNPs, respectively, are successfully fabricated. In order to improve the colloidal stability of MGONCs in physiological solutions (e.g., phosphate buffered saline or PBS solution), MGONCs are further conjugated with polyethylene glycol (PEG). Heating by exposing MGONCs samples to an alternating magnetic field (AMF) show that the obtained nanocomposites are efficient hyperthermia agents. At concentrations as low as 0.1 mg Fe mL?1 and under an 59.99 kA m?1 field, the highest specific absorption rate (SAR) recorded is 1588.83 W g?1 for MGONCs loaded with 14 nm MFNPs. It is also demonstrated that MGONCs are promising as magnetic resonance imaging (MRI) T2 contrast agents. A T2 relaxivity value (r2) as high as 256.2 (mM Fe)?1 s?1 could be achieved with MGONCs loaded with 14 nm MFNPs. The cytotoxicity results show that PEGylated MGONCs exhibit an excellent biocompatibility that is suitable for biomedical applications. 相似文献
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Sandrine Dufort Pierre Mowat Aurélie Dutour Gautier Laurent Elke Bräuer‐Krisch Nirmitha Herath Jean‐Luc Coll Marie Dutreix François Lux Rana Bazzi Claire Billotey Marc Janier Pascal Perriat Géraldine Le Duc Stéphane Roux Olivier Tillement 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(6):1116-1124
Owing to the high atomic number (Z) of gold element, the gold nanoparticles appear as very promising radiosensitizing agents. This character can be exploited for improving the selectivity of radiotherapy. However, such an improvement is possible only if irradiation is performed when the gold content is high in the tumor and low in the surrounding healthy tissue. As a result, the beneficial action of irradiation (the eradication of the tumor) should occur while the deleterious side effects of radiotherapy should be limited by sparing the healthy tissue. The location of the radiosensitizers is therefore required to initiate the radiotherapy. Designing gold nanoparticles for monitoring their distribution by magnetic resonance imaging (MRI) is an asset due to the high resolution of MRI which permits the accurate location of particles and therefore the determination of the optimal time for the irradiation. We recently demonstrated that ultrasmall gold nanoparticles coated by gadolinium chelates (Au@DTDTPA‐Gd) can be followed up by MRI after intravenous injection. Herein, Au@DTDTPA and Au@DTDTPA‐Gd were prepared in order to evaluate their potential for radiosensitization. Comet assays and in vivo experiments suggest that these particles appear well suited for improving the selectivity of the radiotherapy. The dose which is used for inducing similar levels of DNA alteration is divided by two when cells are incubated with the gold nanoparticles prior to the irradiation. Moreover, the increase in the lifespan of tumor bearing rats is more important when the irradiation is performed after the injection of the gold nanoparticles. In the case of treatment of rats with a brain tumor (9L gliosarcoma, a radio‐resistant tumor in a radiosensitive organ), the delay between the intravenous injection and the irradiation was determined by MRI. 相似文献
11.
Weisheng Guo ;Weitao Yang ;Yu Wang ;Xiaolian Sun ;Zhongyun Liu ;Bingbo Zhang ;Jin Chang ;Xiaoyuan Chen 《Nano Research》2014,(11):1581-1591
Inorganic nanoparticles have been introduced into biological systems as useful probes for in vitro diagnosis and in vivo imaging, due to their relatively small size and exceptional physical and chemical properties. A new kind of color- tunable Gd-Zn-Cu-In-S/ZnS （GZCIS/ZnS） quantum dots （QDs） with stable crystal structure has been successfully synthesized and utilized for magnetic resonance （MR） and fluorescence dual modality imaging. This strategy allows successful fabrication of GZCIS/ZnS QDs by incorporating Gd into ZCIS/ZnS QDs to achieve great MR enhancement without compromising the fluorescence properties of the initial ZCIS/ZnS QDs. The as-prepared GZCIS/ZnS QDs show high T1 MR contrast as well as ＂color-tunable＂ photoluminescence （PL） in the range of 550-725 nm by adjusting the Zn/Cu feeding ratio with high PL quantum yield （QY）. The GZCIS/ZnS QDs were transferred into water via a bovine serum albumin （BSA） coating strategy. The resulting Cd-free GZCIS/ZnS QDs reveal negligible cytotoxicity on both HeLa and A549 cells. Both fluorescence and MR imaging studies were successfully performed in vitro and in vivo. The results demonstrated that GZCIS/ZnS QDs could be a dual-modal contrast agent to simultaneously produce strong MR contrast enhancement as well as fluorescence emission for in vivo imaging. 相似文献
12.
Sang‐Yoon Kim Jaemoon Yang Bongjune Kim Jungmin Park Jin‐Suck Suh Yong‐Min Huh Seungjoo Haam Jungho Hwang 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(13):2325-2330
An electrohydrodynamic atomization (EHDA) system that generates an electrospray can achieve particle formation and encapsulation by accumulating an electric charge on liquid flowing out from the nozzle. A novel coaxial EHDA system for continuous fabrication of water‐stable magnetic nanoparticles (MNPs) is established, based on a cone‐jet mode of electrospraying. Systemic variables, such as flow rates from dual nozzles and inducing voltages, are controlled to enable the preparation of water‐soluble MNPs coated by polysorbate 80. The PEGylated MNPs exhibit water stability. The magnetic resonance imaging potential of these MNPs is confirmed by in vivo imaging using a gastric cancer xenograft mouse model. Thus, this advanced coaxial EHDA system demonstrates remarkable capabilities for the continuous encapsulation of MNPs to render them water‐stable while preserving their properties as imaging agents. 相似文献
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Manasmita Das Debasish Mishra Prasanta Dhak Satyajit Gupta Tapas Kumar Maiti Amit Basak Panchanan Pramanik 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(24):2883-2893
A novel, inexpensive biofunctionalization approach is adopted to develop a multimodal and theranostic nanoagent, which combines cancer‐targeted magnetic resonance/optical imaging and pH‐sensitive drug release into one system. This multifunctional nanosystem, based on an ultrasmall superparamagnetic iron oxide (USPIO) nanocore, is modified with a hydrophilic, biocompatible, and biodegradable coating of N‐phosphonomethyl iminodiacetic acid (PMIDA). Using appropriate spacers, functional molecules, such as rhodamine B isothiocyanate, folic acid, and methotrexate, are coupled to the amine‐derivatized USPIO–PMIDA support with the aim of endowing simultaneous targeting, imaging, and intracellular drug‐delivering capability. For the first time, phosphonic acid chemistry is successfully exploited to develop a stealth, multifunctional nanoprobe that can selectively target, detect, and kill cancer cells overexpressing the folate receptor, while allowing real‐time monitoring of tumor response to drug treatment through dual‐modal fluorescence and magnetic resonance imaging. 相似文献
15.
Sheng Wang Zijian Zhou Zhantong Wang Yijing Liu Orit Jacobson Zheyu Shen Xiao Fu Zhi‐Yi Chen Xiaoyuan Chen 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(16)
Activatable imaging probes are promising to achieve increased signal‐to‐noise ratio for accurate tumor diagnosis and treatment monitoring. Magnetic resonance imaging (MRI) is a noninvasive imaging technique with excellent anatomic spatial resolution and unlimited tissue penetration depth. However, most of the activatable MRI contrast agents suffer from metal ion‐associated potential long‐term toxicity, which may limit their bioapplications and clinical translation. Herein, an activatable MRI agent with efficient MRI performance and high safety is developed for drug (doxorubicin) loading and tumor signal amplification. The agent is based on pH‐responsive polymer and gadolinium metallofullerene (GMF). This GMF‐based contrast agent shows high relaxivity and low risk of gadolinium ion release. At physiological pH, both GMF and drug molecules are encapsulated into the hydrophobic core of nanoparticles formed by the pH‐responsive polymer and shielded from the aqueous environment, resulting in relatively low longitudinal relativity and slow drug release. However, in acidic tumor microenvironment, the hydrophobic‐to‐hydrophilic conversion of the pH‐responsive polymer leads to amplified MR signal and rapid drug release simultaneously. These results suggest that the prepared activatable MRI contrast agent holds great promise for tumor detection and monitoring of drug release. 相似文献
16.
Schellenberger E Schnorr J Reutelingsperger C Ungethüm L Meyer W Taupitz M Hamm B 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(2):225-230
Magnetic resonance imaging (MRI) of a target in vivo depends on the surface, size, and particle relaxivity of the target-specific nanoparticles for MRI. Here a new method for decorating very small iron oxide particles (VSOPs) with target-specific ligands is described. The method is based on the electrostatic attraction of the strongly positively charged peptide protamine to the anionic citrate shell of the electrostatically stabilized VSOPs. The protamine coat allows linkage chemistry and chimera technology to functionalize VSOPs or other negative charged surfaces with biologics. Annexin A5 (anxA5)-VSOP utilizing thiol chemistry was generated to couple biologically active anxA5 to VSOPs for in vivo MRI of apoptosis. Annexin A5-VSOP comprises five anxA5 molecules per iron oxide nanoparticle with a high R2 particle relaxivity of 180 000 mM(-1) s(-1) yet small hydrodynamic diameter of only 14.7+/-2.9 nm beneficial for in vivo MRI of extravascular targets. 相似文献
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Derfogail Delcassian Igor Luzhansky Virginia Spanoudaki Matthew Bochenek Collin McGladrigan Amy Nguyen Samuel Norcross Yuhan Zhu Crystal Shuo Shan Reed Hausser Kevin M. Shakesheff Robert Langer Daniel G. Anderson 《Advanced materials (Deerfield Beach, Fla.)》2020,32(16):1904502
Encapsulated beta cell transplantation offers a potential cure for a subset of diabetic patients. Once transplanted, beta cell grafts can help to restore glycemic control; however, locating and retrieving cells in the event of graft failure may pose a surgical challenge. Here, a dual-function nanoparticle-loaded hydrogel microcapsule is developed that enables graft retrieval under an applied magnetic field. Additionally, this system facilitates graft localization via magnetic resonance imaging (MRI), and graft isolation from the immune system. Iron oxide nanoparticles encapsulated within alginate hydrogel capsules containing viable islets are transplanted and the in vitro and in vivo retrieval of capsules containing nanoparticles functionalized with various ligands are compared. Capsules containing islets co-encapsulated with COOH-coated nanoparticles restore normal glycemia in immunocompetent diabetic mice for at least 6 weeks, can be visualized using MRI, and are retrievable in a magnetic field. Application of a magnetic field for 90 s via a magnetically assisted retrieval device facilitates rapid retrieval of up to 94% (±3.1%) of the transplant volume 24 h after surgical implantation. This strategy aids monitoring of cell-capsule locations in vivo, facilitates graft removal at the end of the transplant lifetime, and may be applicable to many encapsulated cell transplant systems. 相似文献
19.
Yasir Javed Lénaic Lartigue Pierre Hugounenq Quoc Lam Vuong Yves Gossuin Rana Bazzi Claire Wilhelm Christian Ricolleau Damien Alloyeau 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(16):3325-3337
Understanding the relation between the structure and the reactivity of nanomaterials in the organism is a crucial step towards efficient and safe biomedical applications. The multi‐scale approach reported here, allows following the magnetic and structural transformations of multicore maghemite nanoflowers in a medium mimicking intracellular lysosomal environment. By confronting atomic‐scale and macroscopic information on the biodegradation of these complex nanostuctures, we can unravel the mechanisms involved in the critical alterations of their hyperthermic power and their Magnetic Resonance imaging T1 and T2 contrast effect. This transformation of multicore nanoparticles with outstanding magnetic properties into poorly magnetic single core clusters highlights the harmful influence of cellular medium on the therapeutic and diagnosis effectiveness of iron oxide‐based nanomaterials. As biodegradation occurs through surface reactivity mechanism, we demonstrate that the inert activity of gold nanoshells can be exploited to protect iron oxide nanostructures. Such inorganic nanoshields could be a relevant strategy to modulate the degradability and ultimately the long term fate of nanomaterials in the organism. 相似文献
20.
Yong Il Park Hyung Min Kim Jeong Hyun Kim Kyung Chul Moon Byeongjun Yoo Kang Taek Lee Nohyun Lee Yoonseok Choi Wooram Park Daishun Ling Kun Na Woo Kyung Moon Seung Hong Choi Hong Seok Park Soo‐Young Yoon Yung Doug Suh Sung Ho Lee Taeghwan Hyeon 《Advanced materials (Deerfield Beach, Fla.)》2012,24(42):5755-5761