Polyethylene glycol modification decreases the cardiac toxicity of carbonaceous dots in mouse and zebrafish models

Aim:

Carbonaceous dots (CDs), which have been used for diagnosis, drug delivery and gene delivery, are accumulated in heart at high concentrations. To improve their biocompatibility, polyethylene glycol-modified CDs (PEG-CDs) were prepared. In this study we compared the cardiac toxicity of CDs and PEG-CDs in mouse and zebrafish models.

Methods:

Mice were intravenously treated with CDs (size: 4.9 nm, 5 mg·kg⁻¹·d⁻¹) or PEG-CDs (size: 8.3 nm, 5 mg·kg⁻¹·d⁻¹) for 21 d. Their blood biochemistry indices, ECG, and histological examination were examined for evaluation of cardiac toxicity. CDs or PEG-CDs was added in incubator of cmlc2 transgenic Zebrafish embryos at 6 hpf, and the shape and size of embryos'' hearts were observed at 48 hpf using a fluorescent microscope. Furthermore, whole-mount in situ hybridization was used to examine the expression of early cardiac marker gene (clml2) at 48 hpf.

Results:

Administration of CDs or PEG-CDs in mice caused mild, but statistically insignificant reduction in serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels detected at 7 d, which were returned to the respective control levels at 21 d. Neither CDs nor PEG-CDs caused significant changes in the morphology of heart cells. Administration of CDs, but not PEG-CDs, in mice caused marked increase of heart rate. Both CDs and PEG-CDs did not affect other ECG parameters. In the zebrafish embryos, addition of CDs (20 μg/mL) caused heart development delay, whereas addition of CDs (80 μg/mL) led to heart malformation. In contrast, PEG-CDs caused considerably small changes in heart development, which was consistent with the results from the in situ hybridization experiments.

Conclusion:

CDs causes greater cardiac toxicity, especially regarding heart development. Polyethylene glycol modification can attenuate the cardiac toxicity of CDs.     

Genotoxic and oxidative responses in coelomocytes of Eisenia fetida and Hediste diversicolor exposed to lipid‐coated CdSe/ZnS quantum dots and CdCl2

The emerging of Quantum Dots utilization in industrial or medicinal fields involved a potentially increase of these nanoparticles in environment. In this work, the genotoxic (comet assay) and oxidative effects (SOD activity, TBARS) of functionalized‐QDs and cadmium chloride were investigated on Hediste diversicolor and Eisenia fetida coelomocytes. Results demonstrated that functionalized‐QDs (QDNs) and cadmium chloride induced DNA damages through different mechanisms that depended on the nano‐ or ionic nature of Cd. The minimal genotoxic concentrations for H. diversicolor (<0.001ng/g for QDNs and CdCl₂) were lower than for E. fetida (between 0.01 and 0.1 ng/g for QDNs, and between 0.001 and 0.01 ng/g for CdCl₂). These results showed that H. diversicolor was more sensitive than E. fetida. The two contaminants had a low impact on the oxidative stress markers. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 918–926, 2015.     

两亲性聚乙烯亚胺修饰量子点构建功能性光学探针用于干细胞治疗的示踪研究

目的：制备新型分子影像探针标记间充质干细胞,以实现细胞荧光成像。方法应用1‐碘十二烷修饰聚乙烯亚胺,构建两亲性大分子。利用大分子自组装性能,包裹疏水性核壳结构CdSe/CdS量子点构建纳米探针。结果该探针在630 nm处呈现出较强的荧光信号,能够促使间充质干细胞高效内吞。体内成像结果显示,与空白对照细胞相比,被标记细胞呈现出显著的光学信号,空白组信号值为1.47 e8[p/s/cm2/sr]/[μW/cm2],实验组信号值为2.78 e8[p/s/cm2/sr]/[μW/cm2]。结论该纳米探针具有良好光学成像性能,可实现细胞标记。     

Advances in understanding the molecular basis of the first steps in color vision

Serving as one of our primary environmental inputs, vision is the most sophisticated sensory system in humans. Here, we present recent findings derived from energetics, genetics and physiology that provide a more advanced understanding of color perception in mammals. Energetics of cis–trans isomerization of 11-cis-retinal accounts for color perception in the narrow region of the electromagnetic spectrum and how human eyes can absorb light in the near infrared (IR) range. Structural homology models of visual pigments reveal complex interactions of the protein moieties with the light sensitive chromophore 11-cis-retinal and that certain color blinding mutations impair secondary structural elements of these G protein-coupled receptors (GPCRs). Finally, we identify unsolved critical aspects of color tuning that require future investigation.     

Experimental quantum coding against qubit loss error

The fundamental unit for quantum computing is the qubit, an isolated, controllable two-level system. However, for many proposed quantum computer architectures, especially photonic systems, the qubits can be lost or can leak out of the desired two-level systems, posing a significant obstacle for practical quantum computation. Here, we experimentally demonstrate, both in the quantum circuit model and in the one-way quantum computer model, the smallest nontrivial quantum codes to tackle this problem. In the experiment, we encode single-qubit input states into highly entangled multiparticle code words, and we test their ability to protect encoded quantum information from detected 1-qubit loss error. Our results prove in-principle the feasibility of overcoming the qubit loss error by quantum codes.     

2017—2019年河南中医药大学第一附属医院抗肿瘤中药制剂使用情况分析

碳点是一种具有优异荧光性质的新兴纳米材料。相比于传统的有机染料和半导体量子点,碳点具有毒性低和生物相容性好等优点。目前,碳点在分析检测、荧光成像、药物运载等诸多领域有着广泛的应用。鹿茸是一味具有多种药效的传统名贵中药,也是罕见的具备再生能力的哺乳动物器官。鹿茸的生物学特性和药效与其化学成分有着密切联系。简要综述了碳点在荧光检测、荧光成像以及光诊疗方面的应用进展,对碳点应用于鹿茸生物学特性及其化学成分分析研究的可行性进行了探讨。     

Development of quantum dot‐based fluorescence lateral flow immunoassay strip for rapid and quantitative detection of serum interleukin‐6

BackgroundInterleukin‐6 (IL‐6) is an inflammatory factor that increases rapidly in response to infectious diseases including sepsis. The aim of this study is to develop a quantum dot (QD)‐based fluorescence lateral flow immunoassay (LFIA) strip that can rapidly and accurately detect IL‐6 levels.MethodsQD‐based LFIA strips were fabricated by conjugating CdSe/ZnS QDs to the IL‐6 antibody. Performance verification and clinical sample analysis were carried out to evaluate the newly developed strip.ResultsQD‐based LFIA strips were successfully fabricated. The test strip''s linear range was 10–4000 pg/ml, with a linear correlation coefficient of R ² ≥ .959. The sensitivity of the test strip was 1.995 pg/ml. The recovery rate was 95.72%–102.63%, indicating satisfying accuracy. The coefficient of variation (CV) of the intra‐assay was 2.148%–3.903%, while the inter‐assay was 2.412%–5.293%, verifying the strip''s high precision. The cross‐reaction rates with various interleukins (IL‐1α, IL‐1β, IL‐2, IL‐4, and IL‐8) and interferon‐γ (IFN‐γ) were all <0.1%. When the strip was placed in a 50°C oven for 1, 2, 3, and 4 weeks, the test results were not significantly altered compared to storage at room temperature. Furthermore, 200 clinical serum samples were analyzed to compare the strip with the Beckman chemiluminescence immunoassay (CLIA) kit, which revealed a high correlation (n = 200, R ² = .9971) for the detection of IL‐6.ConclusionsThe QD‐based test strip can rapidly and quantitatively detect IL‐6 levels, thus meeting the requirement of point‐of‐care test (POCT) and showing excellent clinical prospects.     

Uncommon antinuclear antibody patterns as diagnostic indicators

IntroductionThe clinical significance of common antinuclear antibody (ANA) patterns, such as nuclear homogenous and nuclear speckled patterns with their corresponding specific antibodies, has already been established. However, the clinical relevance of these uncommon ANA patterns have not been well elucidated and these patterns are therefore not reported by most clinical laboratories. We herein report some retrospective data analysis linking patients’ clinical status to several uncommon ANA patterns.MethodsWe retrieved and assessed the patient records for ANA reports generated in our hospital over a period of two years. All testing had been performed using the gold standard Indirect Immunofluorescence Assay.ResultsRecords of 1235 consecutive patients tested for ANA were reviewed. ANA was positive in 330 of these patients with 6.39% found to have uncommon nuclear, cytoplasmic or mitotic sub-patterns. The mitotic spindle (0.89%), cytoplasmic anti-mitochondrial antibodies (0.80%), followed by discrete nuclear dots-multiple (0.72%) were the dominating patterns, with a higher prevalence in females than in males. Systemic lupus erythematosus and rheumatoid arthritis were the two most common autoimmune disorders associated with mitotic spindle fibers and nuclear centromere and nuclear large/coarse speckled ANA patterns.ConclusionThe prevalence of these relatively uncommon ANA patterns was higher than expected. Further evaluation of these patterns along with their corresponding antibodies and their clinical utility must be encouraged. We trust this endeavour will provide diagnostic information in autoimmune and other disease conditions.     

Cellular uptake,elimination and toxicity of CdSe/ZnS quantum dots in HepG2 cells

In this work, the cellular uptake, elimination and toxicity of CdSe/ZnS QDs in HepG2 cells were comprehensively studied using inductively coupled plasma mass spectrometry (ICP-MS), MTT assay, AO/EB staining, and glutathione level and gene expression analysis. ICP-MS analytical results showed that the uptake efficiency of CdSe QDs by HepG2 cells was lower than that of Cd(II) and Se(IV), and the uptake was dose- and time-dependent. The uptake amount was related to the physicochemical properties of QDs, and NH₂-QDs with smaller size were more easily taken up by cells. In combination with various biochemical methodologies, a systematic and thorough quantitative analysis of the in vitro effects of CdSe/ZnS QDs with different coatings was conducted, along with that of Cd (II) and Se (IV). Although Cd(II) above 8.9 μM exhibited obvious toxicity to the cells, no obvious toxicity of four CdSe/ZnS QDs was observed within the tested concentration range (10–100 nM), most likely due to the protection of the ZnS shell and the PEG coating. From the molecular level's point of view, QDs at concentration of 100 nM exhibit obvious impact on the cells, such as increased gene expression (MT1A and CYP1A1), which was positively correlated with the intracellular concentration of QDs.     

Noninvasive measurement of sensory action currents in the cervical cord by magnetospinography

ObjectiveTo obtain magnetic recordings of electrical activities in the cervical cord and visualize sensory action currents of the dorsal column, intervertebral foramen, and dorsal horn.MethodsNeuromagnetic fields were measured at the neck surface upon median nerve stimulation at the wrist using a magnetospinography system with high-sensitivity superconducting quantum interference device sensors. Somatosensory evoked potentials (SEPs) were also recorded. Evoked electrical currents were reconstructed by recursive null-steering beamformer and superimposed on cervical X-ray images.ResultsEstimated electrical currents perpendicular to the cervical cord ascended sequentially. Their peak latency at C5 and N11 peak latency of SEP were well-correlated in all 16 participants (r = 0.94, p < 0.0001). Trailing axonal currents in the intervertebral foramens were estimated in 10 participants. Estimated dorsal–ventral electrical currents were obtained within the spinal canal at C5. Current density peak latency significantly correlated with cervical N13–P13 peak latency of SEPs in 13 participants (r = 0.97, p < 0.0001).ConclusionsMagnetospinography shows excellent spatial and temporal resolution after median nerve stimulation and can identify the spinal root entry level, calculate the dorsal column conduction velocity, and analyze segmental dorsal horn activity.SignificanceThis approach is useful for functional electrophysiological diagnosis of somatosensory pathways.