Qinghai Yuan

Large-Scale Synthesis of Bi(2)S(3) Nanodots as a Contrast Agent for In Vivo X-ray Computed Tomography Imaging

A facile strategy for the large-scale fabrication of Bi(2)S(3) nanodots is presented. Surface modification and control over the size of the nanodots is easily achieved. The as-prepared hydrophilic Bi(2)S(3) nanodots exhibit long in vivo circulation time and, more significantly, a contrast efficacy higher than that of the clinical iodinate agent without any adverse effect.

Fluorescence-enhanced gadolinium-doped zinc oxide quantum dots for magnetic resonance and fluorescence imaging

We report here the development of Gd-doped ZnO quantum dots (QDs) as dual modal fluorescence and magnetic resonance imaging nanoprobes. They are fabricated in a simple, versatile and environmentally friendly method, not only decreasing the difficulty and complexity, but also avoiding the increase of particles size brought about by silica coating procedure in the synthesis of nanoprobes reported previously. These nanoprobes, with exceptionally small size and enhanced fluorescence resulting from the Gd doping, can label successfully the HeLa cells in short time and present no evidence of toxicity or adverse affect on cell growth even at the concentration up to 1 mm. These results show that such nanoprobes have low toxicity, especially in comparison with the traditional PEGylated CdSe/ZnS or CdSe/CdS QDs. In MRI studies, they exert strong positive contrast effect with a large longitudinal relaxivity (r(1)) of water proton of 16 mm(-1) s(-1). Their capability of imaging HeLa cells with MRI implies that they have great potential as MRI contrast agents. Combining the high sensitivity of fluorescence imaging with high spatial resolution of MRI, We expect that the as-prepared Gd-doped Zno QDs can provide a better reliability of the collected data and find promising applications in biological, medical and other fields.

Long-circulating Gd2O3:Yb3+, Er3+ up-conversion nanoprobes as high-performance contrast agents for multi-modality imaging

Due to their unique electric, magnetic, and optical properties, engineered nanostructures have been applied to provide diagnostic, therapeutic, as well as prognostic information about the status of disease. In this study, we report a multifunctional nanoprobe based on PEGylated Gd(2)O(3):Yb(3+), Er(3+) nanorods (denoted as PEG-UCNPs) for in vivo up-conversion luminescence (UCL), T(1)-enhanced magnetic resonance (MR), and X-ray computed tomography (CT) multi-modality imaging. A facile and large-scale hydrothermal system combining the merits of an in situ thermal decomposition method and a surface-modified approach is introduced to construct high-quality PEG-UCNPs. By grafting PEG molecules on the surface of PEG-UCNPs, the nanostructures possess excellent stability against in vivo environment and hold long blood circulation time. Cell-cytotoxicity assay, hemolyticity, as well as post-injection histology, hematology, and inflammation analysis further demonstrate their non-cytotoxic character and indicate further in vivo application. In detail, the capability of PEG-UCNPs as high-performance contrast agents for UCL/MR/CT imaging is evaluated successfully through small-animal experiments. Additionally, pharmacokinetics, biodistribution, and clearance route are studied after intravenous injection in a mouse model, reflecting their overall safety.

Hybrid BaYbF5 Nanoparticles: Novel Binary Contrast Agent for High-Resolution in Vivo X-Ray Computed Tomography Angiography

A novel CT contrast agent denoted as BaYbF(5) @SiO(2) @PEG is presented. The as-prepared nanoparticles exhibit significantly enhanced contrast efficacy relative to clinical iodinated agents and maintain higher X-ray attenuation at different voltages, suitable for diagnostic imaging of various patients. Prolonged circulation time in vivo and low toxicity mean the nanoparticles perform excellently in in-vivo X-ray CT angiography.

Aptamer-Capped Multifunctional Mesoporous Strontium Hydroxyapatite Nanovehicle for Cancer-Cell-Responsive Drug Delivery and Imaging

A novel cancer-cells-triggered controlled-release gadolinium-doped luminescent and mesoporous strontium hydroxyapatite nanorods (designated as Gd:SrHap nanorods) system using cell-type-specific aptamers as caps has been constructed. Aptamers behave as a dual-functional molecule that acts as not only a lid but also a targeted molecular that can be used in an effective way for therapeutically special cancer cells. After incubated with cancer cells, for example, MCF-7 cells, the doxorubicin-loaded and aptamer-capped Gd:SrHap nanorods (designated as Gd:SrHap-Dox-aptamer) can be internalized into MCF-7 cells, resulting in the pore opening and drug releasing. Furthermore, the high biocompatibility and biodegradability Gd:SrHap nanorods with blue autofluorescence and paramagnetism could serve as a good contrast agent of targeting fluorescence and magnetic resonance imaging. We envision that this Gd:SrHap system could play a significant role in developing new generations of site-selective, controlled-release delivery and interactive sensory nanodevices.

Direct visualization of gastrointestinal tract with lanthanide-doped BaYbF5 upconversion nanoprobes

Nanoparticulate contrast agents have attracted a great deal of attention along with the rapid development of modern medicine. Here, a binary contrast agent based on PAA modified BaYbF5:Tm nanoparticles for direct visualization of gastrointestinal (GI) tract has been designed and developed via a one-pot solvothermal route. By taking advantages of excellent colloidal stability, low cytotoxicity, and neglectable hemolysis of these well-designed nanoparticles, their feasibility as a multi-modal contrast agent for GI tract was intensively investigated. Significant enhancement of contrast efficacy relative to clinical barium meal and iodine-based contrast agent was evaluated via X-ray imaging and CT imaging in vivo. By doping Tm(3+) ions into these nanoprobes, in vivo NIR-NIR imaging was then demonstrated. Unlike some invasive imaging modalities, non-invasive imaging strategy including X-ray imaging, CT imaging, and UCL imaging for GI tract could extremely reduce the painlessness to patients, effectively facilitate imaging procedure, as well as rationality economize diagnostic time. Critical to clinical applications, long-term toxicity of our contrast agent was additionally investigated in detail, indicating their overall safety. Based on our results, PAA-BaYbF5:Tm nanoparticles were the excellent multi-modal contrast agent to integrate X-ray imaging, CT imaging, and UCL imaging for direct visualization of GI tract with low systemic toxicity.

Hybrid mesoporous gadolinium oxide nanorods: a platform for multimodal imaging and enhanced insoluble anticancer drug delivery with low systemic toxicity

We present a facile and scalable method to synthesize PEGylated Eu3+ doped mesoporous gadolinium oxide nanorods for multifunctional biomaterials. By incorporating a facile hydrothermal method, an in situ thermal decomposition process and a surface-modified procedure together, the resultant PEGylated Gd2O3:Eu nanorods reveal rod-like morphology, perfect photoluminescent/magnetic properties, as well as well-defined mesopores. Cell-cytotoxicity assays, hemolyticity against human red blood cells and post-injection histology analysis further demonstrate the excellent biocompatibility of the multifunctional nanorods, indicating the feasibility for their use in disease diagnosis and chemotherapy. The capability of nanorods as contrast agents for MR/X-ray/PL imaging is evaluated in detail through preliminary in vivo characterization. Moreover, to overcome the limitations of insoluble anticancer drugs in clinical applications, we further develop a simple but efficient method to prepare hydrophobic drug (Camptothecin) nanocrystallites in the inner voids of nanorods and testify their enhanced chemotherapy efficiency. Our findings indicate the enhanced chemotherapy efficiency of CPT nanocrystallite-loaded nanorods over traditional CPT-loaded nanoparticles. Due to these advantages, the well-designed PEGylated Gd2O3:Eu nanorods are promising for a simultaneous bioimaging and drug delivery system, which show further potential for clinical applications.

PEGylated hybrid ytterbia nanoparticles as high-performance diagnostic probes for in vivo magnetic resonance and X-ray computed tomography imaging with low systemic toxicity

Novel nanoparticulate contrast agents with low systemic toxicity and inexpensive character have exhibited more advantages over routinely used small molecular contrast agents for the diagnosis and prognosis of disease. Herein, we designed and synthesized PEGylated hybrid ytterbia nanoparticles as high-performance nanoprobes for X-ray computed tomography (CT) imaging and magnetic resonance (MR) imaging both in vitro and in vivo. These well-defined nanoparticles were facile to prepare and cost-effective, meeting the criteria as a biomedical material. Compared with routinely used Iobitridol in clinic, our PEG-Yb2O3:Gd nanoparticles could provide much significantly enhanced contrast upon various clinical voltages ranging from 80 kVp to 140 kVp owing to the high atomic number and well-positioned K-edge energy of ytterbium. By the doping of gadolinium, our nanoparticulate contrast agent could perform perfect MR imaging simultaneously, revealing similar organ enrichment and bio-distribution with the CT imaging results. The super improvement in imaging efficiency was mainly attributed to the high content of Yb and Gd in a single nanoparticle, thus making these nanoparticles suitable for dual-modal diagnostic imaging with a low single-injection dose. In addition, detailed toxicological study in vitro and in vivo indicated that uniformly sized PEG-Yb2O3:Gd nanoparticles possessed excellent biocompatibility and revealed overall safety.

Core–shell BaYbF5:Tm@BaGdF5:Yb,Tm nanocrystals for in vivo trimodal UCL/CT/MR imaging

Lanthanide-doped nanocrystals have been researched extensively and used for bioimaging because of their optical properties, magnetic properties and X-ray absorption. Core–shell-structured lanthanide-doped nanocrystals have been developed and characterized by TEM and XRD analysis. The nanocrystals are composed of BaYbF5:0.5% Tm as the core and BaGdF5:20% Yb, 0.5% Tm as the shell. Apart from characterization of the nanocrystals, evaluation of both their cytotoxicity via MTT assays and their long-term toxicity via histological analysis showed that their cytotoxicity was low, indicating the possibility of further in vivo imaging. This work combined the functions of trimodal imaging into one nanoplatform and then UCL, CT, and MR imaging with core–shell-structured nanocrystals were investigated both in vitro and in vivo. Taking into consideration its structural characteristics and trimodal imaging abilities, it is expected that the developed multifunctional nanoplatform may be potentially useful for diagnosing diseases at an early stage.

Primary Pericardial Mesothelioma: A Rare Entity

Primary pericardial malignant mesothelioma is an extremely rare neoplasm that arises from the pericardial mesothelial cell layers. Clinical symptoms and signs are frequently nonspecific, and the diagnosis is usually made after surgery or at autopsy. There is no standard treatment for pericardial mesothelioma; nonetheless, radical surgery is the mainstay of therapy for localized disease. The neoplasm is highly aggressive and carries a dismal prognosis with an overall survival of less than six months. This paper presents a case study of a 68-year-old patient with a primary pericardial malignant mesothelioma. Radiologic evaluation revealed a small nodule in the posterior pericardium with pericardial and bilateral pleural effusions. The diagnosis was established after surgery by histological and immunohistochemical studies. The patient remained alive and free of disease for about 24 months; however, due to rapid local recurrence, the patient died 27 months after the surgical treatment.