经聚乙烯亚胺钝化的荧光碳点负载阿霉素抑制非小细胞肺癌细胞增殖、迁移侵袭的治疗研究

目的研究利用经聚乙烯亚胺（PEI）钝化的荧光碳点（CD）装载阿霉素（DOX）进行药物递送，旨在增加DOX对非小细胞肺癌的治疗作用，减少DOX的心肌毒性。 方法通过一步微波加热法将甘油和PEI的混合物制备成CD-PEI，并通过静电效应将DOX装载至CD-PEI。采用CCK8实验检测CD-PEI-DOX对非小细胞肺癌细胞A549的增殖能力的影响；Transwell实验评估CD-PEI-DOX对A549细胞迁移侵袭能力的影响；最后通过体内动物实验评估CD-PEI-DOX的心肌毒性以及对非小细胞肺癌皮下肿瘤生长的抑制效果。 结果体外细胞实验证实，对比单纯的DOX处理组，CD-PEI-DOX对非小细胞肺癌A549细胞增殖、迁移侵袭能力的抑制作用更为显著。体内实验证实，CD-PEI-DOX纳米复合物治疗组小鼠心肌细胞结构完整，并且能有效抑制小鼠皮下肺癌肿瘤的生长。 结论经PEI钝化的荧光碳点负载阿霉素能显著提高DOX对非小细胞肺癌的治疗效果，并减少DOX对心脏的毒性作用。运用CD-PEI纳米颗粒改善化疗药物递送的治疗方案取得了初步证实，这可为肺癌化学治疗提供新思路，具有广大的临床应用前景。     

Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists

The Earth’s mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists’ education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.     

Stabilization and formulation of a recombinant Human Cytomegalovirus vector for use as a candidate HIV-1 vaccine

Live attenuated viral vaccine/vector candidates are inherently unstable and infectivity titer losses can readily occur without defining appropriate formulations, storage conditions and clinical handling practices. During initial process development of a candidate vaccine against HIV-1 using a recombinant Human Cytomegalovirus vector (rHCMV-1), large vector titer losses were observed after storage at 4 °C and after undergoing freeze-thaw. Thus, the goal of this work was to develop candidate frozen liquid formulations of rHCMV-1 with improved freeze-thaw and short-term liquid stability for potential use in early clinical trials. To this end, a virus stability screening protocol was developed including use of a rapid, in vitro cell-based immunofluorescence focus assay to quantitate viral titers. A library of ∼50 pharmaceutical excipients (from various known classes of additives) were evaluated for their effect on vector stability after freeze-thaw cycling or incubation at 4 °C for several days. Certain additives including sugars and polymers (e.g., trehalose, sucrose, sorbitol, hydrolyzed gelatin, dextran 40) as well as removal of NaCl (lower ionic strength) protected rHCMV-1 against freeze-thaw mediated losses in viral titers. Optimized solution conditions (e.g., solution pH, buffers and sugar type) slowed the rate of rHCMV-1 titer losses in the liquid state at 4 °C. After evaluating various excipient combinations, three new candidate formulations were designed and rHCMV-1 stability was benchmarked against both the currently-used and a previously reported formulation. The new candidate formulations were significantly more stable in terms of reducing rHCMV-1 titer losses after 5 freeze-thaw cycles or incubation at 4 °C for 30 days. This case study highlights the utility of semi-empirical design of frozen liquid formulations of a live viral vaccine candidate, where protection against infectivity titer losses due to freeze-thaw and short-term liquid storage are sufficient to enable more rapid initiation of early clinical trials.     

以机油为分散剂高温热解人发合成新型碳点及其生物效应研究

目的以机油为分散剂高温热解人发后发现新型纳米碳点,通过动物实验评价了该碳点的生物效应。方法利用高温热解法对人发和机油进行炭化,对炭化产物进行萃取、过滤分离和透析得到一种具有水溶性的新型物质碳点,并命名为JYRF-CDs。利用透射电子显微镜(TEM)、高分辨透射电子显微镜(HR-TEM)、紫外-可见分光光谱、傅里叶变换红外光谱、荧光光谱、X射线光电子能谱分析(XPS)等多种方法对JYRF-CDs进行表征,利用小鼠单核巨噬细胞RAW264.7细胞进行CCK-8毒性实验来评价JYRF-CDs的安全性,并通过小鼠耳肿胀实验和小鼠醋酸扭体实验对JYRF-CDs的生物效应进行评价。结果 JYRF-CDs外形为类球形,粒径均匀分布在1.8～3.6 nm,晶格间距为0.219 7 nm。细胞毒性实验结果显示,JYRF-CDs具有低毒性,动物实验结果表明JYRF-CDs具有良好的抗炎和镇痛作用。结论首次以机油为分散剂高温热解人发后发现一种全新的碳点JYRF-CDs,以JYRF-CDs为突破口,更加明确阐释以机油为分散剂高温热解人发后炭化产物具有生物效应的物质基础,为纳米类成分的研究提供了一种新方法。     

Seawater activated TiO2 photocatalyst for degradation of organic compounds

The world's oceans are polluted by a continuous inflow of plastic. Plastic fragments finally into microplastic, which can be taken up, for example by plankton, and subsequently by the entire ocean food web. An approach to reduce plastic pollution constitutes the accelerated microplastic degradation in marine environments. TiO₂ (anatase) is commonly used as an oxidative photocatalyst and well known to catalyze the degradation of organic compounds upon UV irradiation.In this study, a selective activation of TiO₂ (anatase) particles encapsulated by Ca- or Sr-polyphosphate is presented. The TiO₂ polyphosphate core-shell particles are envisaged as additives in plastic products. The highly concentrated cations from seawater, viz. Na⁺ and Mg²⁺, displace the Ca²⁺ or Sr²⁺ cations from the polyphosphate shell. As a result, the polyphosphate coating dissolves and thus the photocatalytically active TiO₂ core is released. The stability of the TiO₂ polyphosphate particles in potable water and the seawater activated disintegration of methylene blue, methyl methacrylate, terephtalic acid, and poly(vinyl alcohol) was shown. It has been demonstrated, that the sweetwater stable polyphosphate coating degrades in the presence of seawater, which could be monitored by the activation of the TiO₂ (anatase) photocatalyst.     

MAP4K4 deficiency in CD4+ T cells aggravates lung damage induced by ozone-oxidized black carbon particles

As the main composition of combustion, black carbon (BC) is becoming more and more noticeable at home and abroad. Ozone-oxidized black carbon (oBC) was produced through aging of ozone, one of the near-surface pollutants, to black carbon. And oBC was found to be more oxidation and cell toxicity when compared with BC. Besides, as a key cell of immunity, whether CD4⁺ T cell would involve in lung inflammation induced by particular matter is still unclear. This study aims to observe the effect of oBC on lung damage in mice and discuss how the functional MAP4K4 defect CD4⁺ T cells (conditional knockout of MAP4K4) presents its role in this process.In our study, MAP4K4 deletion in CD4⁺ T cells (MAP4K4 cKO) could increase cell number of macrophages, lymphocytes and neutrophils in bronchoalveolar lavage fluid (BALF) exposed to oBC. MAP4K4 deletion in CD4⁺ T cell also affected CD4⁺ T cell differentiation in mediastinal lymph nodes after oBC stimulation. The number of CD4⁺ IL17⁺ T cell increased obviously. The levels of IL-6 mRNA of lung in MAP4K4 cKO mice was higher than that in wild type mice after exposed to oBC, while the level of IL-6 in BALF had the same trend. Histological examination showed that MAP4K4 deletion in CD4⁺ T cells affected lung inflammation induced by oBC. Results indicated that MAP4K4 cKO in CD4⁺ T cells upgraded the level of inflammation in lung when exposed to oBC, which may be connected to the CD4⁺ T cell differentiation and JNK, ERK and P38 pathways.     

Ultrasound-Assist Extrusion Methods for the Fabrication of Polymer Nanocomposites Based on Polypropylene/Multi-Wall Carbon Nanotubes

Isotactic polypropylenes (iPP) with different melt flow indexes (MFI) were used to fabricate nanocomposites (NCs) with 10 wt % loadings of multi-wall carbon nanotubes (MWCNTs) using ultrasound-assisted extrusion methods to determine their effect on the morphology, melt flow, and electrical properties of the NCs. Three different types of iPPs were used with MFIs of 2.5, 34 and 1200 g/10 min. Four different NC fabrication methods based on melt extrusion were used. In the first method melt extrusion fabrication without ultrasound assistance was used. In the second and third methods, an ultrasound probe attached to a hot chamber located at the exit of the die was used to subject the sample to fixed frequency and variable frequency, respectively. The fourth method is similar to the first method, with the difference being that the carbon nanotubes were treated in a fluidized air-bed with an ultrasound probe before being used in the fabrication of the NCs with no ultrasound assistance during extrusion. The samples were characterized by MFI, Optical microscopy (OM), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), electrical surface resistivity, and electric charge. MFI decreases in all cases with addition of MWCNTs with the largest decrease observed for samples with the highest MFI. The surface resistivity, which ranged from 10¹³ to 10⁵ Ω/sq, and electric charge, were observed to depend on the ultrasound-assisted fabrication method as well as on the melt flow index of the iPP. A relationship between agglomerate size and area ratio with electric charge was found. Several trends in the overall data were identified and are discussed in terms of MFI and the different fabrication methods.