基于表面活性剂的纳米包膜微泡超声造影剂

采用声空化的方法,以3种酯类表面活性剂作为微泡的纳米包膜材料进行了静脉注射微泡超声造影剂的制备研究,实验研究了超声功率与超声时间的选择、磷酸盐缓冲溶液pH值对微泡产量的影响、通气方式的选择、稀释液对微泡流动性的影响、振动对微泡的影响,研究了微泡的保存方式,并对制备出的微泡超声造影剂进行了体外及动物体内造影成像效果研究,给出了实验犬肾脏造影灌注的结果.     

Bola型表面活性剂

阐述了Bola型表面活性剂的基本性质,并介绍了国内外关于Bola型化合物的结构及其聚集行为等性能的研究进展。介绍的Bola型表面活性剂有糖配体非离子型、富勒烯结构、穴状配体、呈液晶相和能形成离子通道的Bola型化合物。     

Bola型表面活性剂2.Bola化合物囊泡

Bola型两亲化合物分子因具有中部是疏水基,两端为亲水基团的特殊结构,可在水中聚集形成单层类脂膜（MLM）和单分子层囊泡（MLM囊泡）。许多单分子层囊泡具有良好的热稳定性。具有两个不同亲水基团的bola化合物可形成内外表面分别由不同亲水基团组成的不对称单分子层囊泡。Bola化合物可以参与到普通两亲化合物所形成的双层类脂膜中并改变膜的稳定性,还可成为连接双层类脂膜内外的电子或离子通道。     

Bola型表面活性剂自组装囊泡的研究进展

介绍了Bola型表面活性剂的结构特点,并详细概括了Bola型表面活性剂自组装形成单分子囊泡的原理、囊泡与胶束的相互转变及区别。综述了Bola型表面活性剂自组装囊泡的合成研究进展,并对其在纳米材料、催化作用、药物缓释、模拟生物离子通道等方面的应用作了介绍。最后对Bola型表面活性剂的研究前景进行了展望。     

Bola型表面活性剂的研究进展

Bola型表面活性剂是以一根疏水链连接2个亲水基团构成的两亲化合物.介绍了Bola型表面活性剂分子的结构与性能,概述了Bola型双亲表面活性剂与传统表面活性剂相比的优点及其在液相中形成的囊泡的特征.重点介绍了各种类型的Bola型双亲表面活性剂的主要合成方法及用途.最后对其研究前景作了展望.     

氧化胺型表面活性剂

一、前言氧化胺是由相应的叔胺氧化制得,是一类十分重要的两性表面活性剂。它具有优良的抗静电性、乳化性、分散性及良好的生物降解作用。此外它还具育其它表而活性剂无可比拟的极低的生理毒性。氧化胺对皮肤作用柔和,极小刺激性,并具有保湿、杀菌、防霉等作用。能使皮肤光滑、柔软、对头发有     

阴阳离子表面活性剂复配制备囊泡的研究

采用阴离子表面活性剂十二烷基苯磺酸钠与阳离子表面活性剂十二烷基三甲基氯化铵复配,在合适的比例自发形成囊泡。考察了形成囊泡的复配比例,发现温度升高和滴加有机溶剂都会使囊泡稳定时间更长,通过粒度分析仪检测囊泡的平均粒径在140nm左右,并且囊泡大小均匀。     

表面活性剂对泡载分离谷氨酸菌体的影响

本文考察了表面活性剂种类及浓度对泡载分离谷氨酸菌体的影响．结果表明，阳离子型表面活性剂对泡载分离菌体的影响趋势相同，不同离子型表面活性剂对分离菌体的作用机理不同；添加一定量絮凝剂可大大提高菌体分离效率；在发酵液中添加一定浓度表面活性剂和絮凝剂，可获得最佳分离效果．利用建立的动力学模型对实验数据进行了关联，结果较好     

醇醚型表面活性剂分析的新进展

本文主要介绍了近年来国内外在醇醚型表面活性剂定性分析及定量测定分子量分布方面研究所取得的进展;重点介绍了TLC、HPLC、GC、及MS法在其研究方面的应用;并且就各种分析方法的特点、应用范围及发展前景作了简单的评述。     

Ultrasound-Based Molecular Imaging of Tumors with PTPmu Biomarker-Targeted Nanobubble Contrast Agents

Ultrasound imaging is a widely used, readily accessible and safe imaging modality. Molecularly-targeted microbubble- and nanobubble-based contrast agents used in conjunction with ultrasound imaging expand the utility of this modality by specifically targeting and detecting biomarkers associated with different pathologies including cancer. In this study, nanobubbles directed to a cancer biomarker derived from the Receptor Protein Tyrosine Phosphatase mu, PTPmu, were evaluated alongside non-targeted nanobubbles using contrast enhanced ultrasound both in vitro and in vivo in mice. In vitro resonant mass and clinical ultrasound measurements showed gas-core, lipid-shelled nanobubbles conjugated to either a PTPmu-directed peptide or a Scrambled control peptide were equivalent. Mice with heterotopic human tumors expressing the PTPmu-biomarker were injected with PTPmu-targeted or control nanobubbles and dynamic contrast-enhanced ultrasound was performed. Tumor enhancement was more rapid and greater with PTPmu-targeted nanobubbles compared to the non-targeted control nanobubbles. Peak tumor enhancement by the PTPmu-targeted nanobubbles occurred within five minutes of contrast injection and was more than 35% higher than the Scrambled nanobubble signal for the subsequent two minutes. At later time points, the signal in tumors remained higher with PTPmu-targeted nanobubbles demonstrating that PTPmu-targeted nanobubbles recognize tumors using molecular ultrasound imaging and may be useful for diagnostic and therapeutic purposes.     

Polydisulfide Based Biodegradable Macromolecular Magnetic Resonance Imaging Contrast Agents

Macromolecular Gd(III) complexes are advantageous over small molecular Gd(III) complexes in contrast enhanced magnetic resonance imaging (MRI) because of their prolonged blood circulation and preferential tumor accumulation. However, macromolecular contrast agents have not been approved for clinical applications because of the safety concerns related to their slow body excretion. Polydisulfide Gd(III) complexes have been designed and developed as biodegradable macromolecular MRI contrast agents to alleviate the concerns by facilitating the clearance of Gd(III) complexes from the body. These agents initially behave as macromolecular agents and result in superior contrast enhancement in the vasculature and tumor tissues. They can then be readily degraded in vivo into small molecular chelates that can rapidly excrete from the body via renal filtration after the MRI examinations. Various polydisulfide Gd(III) complexes have been prepared as biodegradable macromolecular MRI contrast agents. These agents have resulted in strong contrast enhancement in the vasculature and tumor tissue in animal models with minimal long-term tissue accumulation comparable to small molecular contrast agents. Polydisulfide Gd(III) complexes are promising for further clinical development as safe and effective biodegradable macromolecular MRI contrast agents for cardiovascular and cancer imaging. The review summarizes the chemistry and properties of polydisulfide Gd(III) complexes.     

碘基CT造影剂的研究进展

作为一种成熟的组织成像手段, CT被广泛应用于各种科学研究和临床检测。碘作为一种经典的X-ray衰减原子,将其引入而得到的CT造影剂已被广泛应用于临床。含碘CT造影剂在增加水溶性、降低渗透压和粘度、赋予靶向功能等多方面的研究也受到广泛的关注。近年来含碘造影剂在低生物毒性和组织特异性等方面的研究成果不断被报道。本文就近年来含碘造影剂的发展及研究现状进行了综述。     

Ingestible Contrast Agents for Gastrointestinal Imaging

Gastrointestinal (GI) ailments cover a wide variety of diseases involving the esophagus, stomach, small intestine, large intestine, and rectum. They bring about many inconveniences in daily life in chronic diseases and can even be life threatening in acute cases. Rapid and safe detection approaches are essential for early diagnosis and timely management. Contrast agents for GI imaging can enhance contrast to distinguish abnormal lesions from normal structures. Computed tomography and magnetic resonance imaging are two important diagnostic tools for the evaluation of GI conditions. This review mainly involves several common GI diseases, including inflammatory diseases, intestinal tumors, diarrhea, constipation, and gastroesophageal reflux diseases. Selected contrast agents, such as barium sulfate, iodine-based agents, gadolinium-based agents, and others, are summarized. Going forward, continued endeavors are being made to develop more emerging contrast agents for other imaging modalities.     

Contrast Agents for Photoacoustic and Thermoacoustic Imaging: A Review

Photoacoustic imaging (PAI) and thermoacoustic imaging (TAI) are two emerging biomedical imaging techniques that both utilize ultrasonic signals as an information carrier. Unique advantages of PAI and TAI are their abilities to provide high resolution functional information such as hemoglobin and blood oxygenation and tissue dielectric properties relevant to physiology and pathology. These two methods, however, may have a limited detection depth and lack of endogenous contrast. An exogenous contrast agent is often needed to effectively resolve these problems. Such agents are able to greatly enhance the imaging contrast and potentially break through the imaging depth limit. Furthermore, a receptor-targeted contrast agent could trace the molecular and cellular biological processes in tissues. Thus, photoacoustic and thermoacoustic molecular imaging can be outstanding tools for early diagnosis, precise lesion localization, and molecular typing of various diseases. The agents also could be used for therapy in conjugation with drugs or in photothermal therapy, where it functions as an enhancer for the integration of diagnosis and therapy. In this article, we present a detailed review about various exogenous contrast agents for photoacoustic and thermoacoustic molecular imaging. In addition, challenges and future directions of photoacoustic and thermoacoustic molecular imaging in the field of translational medicine are also discussed.     

Click‐Chemistry‐Mediated Rapid Microbubble Capture for Acute Thrombus Ultrasound Molecular Imaging

Bioorthogonal coupling chemistry has been studied as a potentially advantageous approach for molecular imaging because it offers rapid, efficient, and strong binding, which might also benefit stability, production, and chemical conjugation. The inverse‐electron‐demand Diels–Alder reaction between a 1,2,4,5‐tetrazine and trans‐cyclooctene (TCO) is an example of a highly selective and rapid bioorthogonal coupling reaction that has been used successfully to prepare targeted molecular imaging probes. Here we report a fast, reliable, and highly sensitive approach, based on a two‐step pretargeting bioorthogonal approach, to achieving activated‐platelet‐specific CD62p‐targeted thrombus ultrasound molecular imaging. Tetrazine‐modified microbubbles (tetra‐MBs) could be uniquely and rapidly captured by subsequent click chemistry of thrombus tagged with a trans‐cyclooctene‐pretreated CD62p antibody. Moreover, such tetra‐MBs showed great long‐term stability under physiological conditions, thus offering the ability to monitor thrombus changes in real time. We demonstrated for the first time that a bioorthogonal targeting molecular ultrasound imaging strategy based on tetra‐MBs could be a simple but powerful tool for rapid diagnosis of acute thrombosis.     

靶向载药PLA复合微泡超声造影剂的制备

目的制备一种基于生物材料氧化石墨烯(GO)靶向性和载药性的聚乳酸(PLA)复合微泡超声造影剂,并对其理化特性和体外超声显影效果进行研究。方法采用复乳化-溶剂挥发法制备靶向载阿霉素PLA复合微泡超声造影剂(FA-DOX/GO-DOX/PLA)。对复合微泡外观形态、粒径、电位和复合微泡中DOX和GO的负载率进行表征。使用多普勒彩色超声仪观察复合微泡的超声显影效果。结果所制备靶向载药PLA复合微泡呈规则圆整的球形,粒径分布集中,平均粒度为600 nm左右,Zeta电位为(-37.5±10.0)m V,复合微泡中DOX负载率为7.42%、GO负载率为19.56%,复合微泡超声造影功能显著。结论制备的靶向载药PLA复合微泡粒径均匀、载药率较高、稳定性较好,超声显影效果理想。     

基于微米气泡的臭氧氧化效果

采用臭氧微米气泡曝气和微孔曝气两种曝气方式对腐殖酸配水进行臭氧氧化处理。在水深为2 m的条件下,考察了不同臭氧投加量和水力停留时间的条件下,两种曝气方式的臭氧吸收率和利用率及去除有机物的效能。结果表明两种曝气方式的臭氧吸收率和利用率都随着臭氧投加量的增加而降低,随着水力停留时间的增加而增加。然而,在相同的条件下,臭氧微米气泡曝气方式的臭氧吸收率、利用率及对有机物(COD)的去除率高于微孔曝气方式,提高比例分别为11%~22%、4%~30%和7%~24%。该研究为臭氧微米气泡技术在饮用水厂中的应用提供了一定的参考。     

Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

Biocompatible poly-[N-(2-hydroxyethyl)-d,l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C₁₆) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C₁₆-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (¹H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C₁₆-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C₁₆-ED-DOTA-Gd.