Fluorination Enhances NIR-II Fluorescence of Polymer Dots for Quantitative Brain Tumor Imaging

Here, we describe a fluorination strategy for semiconducting polymers for the development of highly bright second near-infrared region (NIR-II) probes. Tetrafluorination yielded a fluorescence QY of 3.2 % for the polymer dots (Pdots), over a 3-fold enhancement compared to non-fluorinated counterparts. The fluorescence enhancement was attributable to a nanoscale fluorous effect in the Pdots that maintained the molecular planarity and minimized the structure distortion between the excited state and ground state, thus reducing the nonradiative relaxations. By performing through-skull and through-scalp imaging of the brain vasculature of live mice, we quantitatively analyzed the vascular morphology of transgenic brain tumors in terms of the vessel lengths, vessel branches, and vessel symmetry, which showed statistically significant differences from the wild type animals. The bright NIR-II Pdots obtained through fluorination chemistry provide insightful information for precise diagnosis of the malignancy of the brain tumor.     

Design,Synthesis and In-Vitro Biological Evaluation of Antofine and Tylophorine Prodrugs as Hypoxia-Targeted Anticancer Agents

Phenanthroindolizidines, such as antofine and tylophorine, are a family of natural alkaloids isolated from different species of Asclepiadaceas. They are characterized by interesting biological activities, such as pronounced cytotoxicity against different human cancerous cell lines, including multidrug-resistant examples. Nonetheless, these derivatives are associated with severe neurotoxicity and loss of in vivo activity due to the highly lipophilic nature of the alkaloids. Here, we describe the development of highly polar prodrugs of antofine and tylophorine as hypoxia-targeted prodrugs. The developed quaternary ammonium salts of phenanthroindolizidines showed high chemical and metabolic stability and are predicted to have no penetration through the blood–brain barrier. The designed prodrugs displayed decreased cytotoxicity when tested under normoxic conditions. However, their cytotoxic activity considerably increased when tested under hypoxic conditions.     

恶性肿瘤的传质问题（Ⅰ）——流体动力学部分

本文提出肿瘤内部液体和药物传质的三重介质模型·在这部分，研究间隙压力和对流的作用·对于孤立肿瘤和被正常组织包围的肿瘤得到了分析解·计算结果与实验一致，即组织间隙的高压是阻碍药物进入肿瘤的主要原因·文章详细分析了降低间隙压力的参数·     

彩色多普勒超声结合弹性成像技术在鉴别乳腺良恶性肿瘤中的应用价值

本文对彩色多普勒超声(CDUs)结合弹性成像技术(UE)在鉴别乳腺良恶性肿瘤中的应用价值进行了分析。选取2018年1月~2019年2月本院乳腺肿瘤患者103例为研究对象,所有患者均给予CDUs、UE检查,以病理检查为对照,分析CDUs、UE及二者结合对乳腺良恶性肿瘤的鉴别价值。病理检查显示,103例乳腺肿瘤患者中,恶性48例(46.60%)、良性55例(53.40%);乳腺肿瘤恶性者CDUs、UE得分明显高于良性者,差异有统计学意义(P<0.05);在鉴别乳腺良恶性肿瘤的敏感度、特异度、准确度中,CDUs为79.17%、72.73%、75.73%,UE为75.00%、65.45%、69.90%,CDUs与UE结合为95.83%、90.91%、93.20%,CDUs结合UE明显高于CDUs、UE,差异有统计学意义(P<0.05)。本文证实CDUs、UE对乳腺良恶性肿瘤具有良好的鉴别价值,且CDUs结合UE的鉴别价值更高。     

In VivoLactate Editing with Simultaneous Detection of Choline, Creatine, NAA, and Lipid Singlets at 1.5 T Using PRESS Excitation with Applications to the Study of Brain and Head and Neck Tumors

Two T2-independentJ-difference lactate editing schemes for the PRESS magnetic resonance spectroscopy localization sequence are introduced. The techniques, which allow for simultaneous acquisition of the lactate doublet (1.3 ppm) and edited singlets upfield of and including choline (3.2 ppm), exploit the dependence of the in-phase intensity of the methyl doublet upon the time interval separating two inversion (BASING) pulses applied to its coupling partner after initial excitation. Editing method 1, which allows for echo times TE =n/J(n= 1, 2, 3, …), alters the BASING carrier frequency for each of two cycles so that, for one cycle, the quartet is inverted, whereas, for the other cycle, the quartet is unaffected. Method 2, which also provides water suppression, allows for editing for TE > 1/Jby alternating, between cycles, the time interval separating the inversion pulses. Experimental results were obtained at 1.5 T using a Shinnar Le–Roux-designed maximum phase inversion pulse with a filter transition bandwidth of 55 Hz. Spectra were acquired from phantoms andin vivofrom the human brain and neck. In a neck muscle study, the lipid suppression factor, achieved partly through the use of a novel phase regularization algorithm, was measured to be over 10³. Spectra acquired from a primary brain and a metastatic neck tumor demonstrated the presence of lactate and choline signals consistent with abnormal spectral patterns. The advantages and limitations of the methods are analyzed theoretically and experimentally, and significance of the results is discussed.