Use of mucolytics to enhance magnetic particle retention at a model airway surface

A previous study has shown that retention of magnetic particles at a model airway surface requires prohibitively strong magnetic fields. As mucus viscoelasticity is the most significant factor contributing to clearance of magnetic particles from the airway surface, mucolytics are considered in this study to reduce mucus viscoelasticity and enable particle retention with moderate strength magnetic fields. The excised frog palate model was used to simulate the airway surface. Two mucolytics, N-acetylcysteine (NAC) and dextran sulfate (DS) were tested. NAC was found to enable retention at moderate field values (148 mT with a gradient of 10.2 T/m), whereas DS was found to be effective only for sufficiently large particle concentrations at the airway surface. The possible mechanisms for the observed behavior with different mucolytics are also discussed based on aggregate formation and the loading of cilia.     

Distinguishable Targeting of Non-Small Cell Lung Cancer Using Hyaluronan Functionalized Platinum Nanoclusters and Their Inhibition Behaviors of Proliferation,Invasion, Migration

Lung cancer is the leading cause of cancer deaths worldwide and most cancer patients receiving conventional chemotherapy suffer from severe side effects due to the non-selective effects of chemotherapeutic drugs on normal cells. Targeted nanomaterials can obtain excellent accumulation at the tumor site through their active or passive targeting mechanisms, thereby reducing the toxicity of the drugs in various ways. In this study, hyaluronic acid (HA) which could specifically bind to CD44 on the surface of tumor cells, was used to modify amine-caged platinum nanoclusters (Pt NCs-NH₂) to obtain targeting HA-Pt NCs-NH₂. Based on the differential expression of CD44 on the surface of three lung cells (non-small cell lung cancer cell H1299, small cell lung cancer cell H446, and embryonic lung fibroblast HFL1), HA-Pt NCs-NH₂ can differentially enter the three cells and achieve their targeting of non-small cell lung cancer cell (NSCLC) cells. Pt NCs significantly inhibited the proliferation, migration and invasion of NSCLC cells and induced their apoptosis in comparison of classical cisplatin and carboplatin, showing a bright future in early diagnosis and treatment of NSCLC.     

一种新型的交联极化聚合物的合成及性能研究

以成膜性能优异、主链上含有多个羟基的聚双酚A二缩水甘油醚-苯胺(BPAN)为骨架,将二阶非线性光学活性发色团分子以键合形式挂接到聚合物主链上,形成新型侧链型聚合物.此聚合物保留了原聚合物体系成膜性好和可进一步交联等优点.极化过程中以含有异氰酸酯基的同种发色团分子作为交联剂,得到发色团含量进一步提高的交联型极化聚合物.采用衰减全反射法(ATR)测得体系的电光系数(r₃₃)为6.7 pm/V(1315 nm).     

酞菁在光动力治疗中的应用

光动力治疗因具有低毒、副作用小、抗癌广谱、高选择性等优势, 正吸引着人们越来越多的关注。提高光敏剂的选择性和光毒性已经成为研究的热点。本文简单介绍了光敏剂的发展历程, 并对酞菁类第三代光动力治疗光敏剂的最新研究进展进行了论述。     

连续混沌系统的非线性自适应预测跟踪控制

基于混沌时间序列的非线性自适应预测原理,用一种sigmoid-Volterra自适应预测滤波器研究了连续混沌系统的非线性自适应预测跟踪控制.通过对Lorenz,R?ssler等典型混沌系统的控制,仿真证实了这种sigmoid-Volterra自适应预测控制器的有效性.这种方法的优点在于它既不需要知道精确的混沌系统模型,也不需要进行系统模型辨识. 关键词： 混沌 sigmoid-Volterra自适应预测滤波器 非线性自适应预测跟踪     

A Review on Cancer Immunotherapy and Applications of Nanotechnology to Chemoimmunotherapy of Different Cancers

Clinically, different approaches are adopted worldwide for the treatment of cancer, which still ranks second among all causes of death. Immunotherapy for cancer treatment has been the focus of attention in recent years, aiming for an eventual antitumoral effect through the immune system response to cancer cells both prophylactically and therapeutically. The application of nanoparticulate delivery systems for cancer immunotherapy, which is defined as the use of immune system features in cancer treatment, is currently the focus of research. Nanomedicines and nanoparticulate macromolecule delivery for cancer therapy is believed to facilitate selective cytotoxicity based on passive or active targeting to tumors resulting in improved therapeutic efficacy and reduced side effects. Today, with more than 55 different nanomedicines in the market, it is possible to provide more effective cancer diagnosis and treatment by using nanotechnology. Cancer immunotherapy uses the body’s immune system to respond to cancer cells; however, this may lead to increased immune response and immunogenicity. Selectivity and targeting to cancer cells and tumors may lead the way to safer immunotherapy and nanotechnology-based delivery approaches that can help achieve the desired success in cancer treatment.     

Hyperbranched Polyglycerol‐Grafted Superparamagnetic Iron Oxide Nanoparticles: Synthesis,Characterization, Functionalization,Size Separation,Magnetic Properties,and Biological Applications

For biomedical application of nanoparticles, the surface chemical functionality is very important to impart additional functions, such as solubility and stability in a physiological environment, and targeting specificity as an imaging probe and a drug carrier. Although polyethylene glycol (PEG) has been used extensively, here, it is proposed that hyperbranched polyglycerol (PG) is a good or even better alternative to PEG. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared using a polyol method are directly functionalized with PG through ring‐opening polymerization of glycidol. The resulting SPION‐PG is highly soluble in pure water (>40 mg mL^?1) and in a phosphate buffer solution (>25 mg mL^?1). Such high solubility enables separation of SPION‐PG according to size using size exclusion chromatography (SEC). The size‐separated SPION‐PG shows a gradual increase in transverse relaxivity (r₂) with increasing particle size. For biological application, SPION‐PG is functionalized through multistep organic transformations (–OH → –OTs (tosylate) → –N₃ → –RGD) including click chemistry as a key step to impart targeting specificity by immobilization of cyclic RGD peptide (Arg‐Gly‐Asp‐D ‐Tyr‐Lys) on the surface. The targeting effect is demonstrated by the cell experiments; SPION‐PG‐RGD is taken up by the cells overexpressing α_vβ₃‐integrin such as U87MG and A549.     

聚合物胶束结合靶向在肿瘤化疗中的研究进展

肿瘤研究的一个主要方向是开发高效无毒副作用的药物载体系统。聚合物胶束由内部可装载难溶性药物的疏水内核,外部能提高体内运输作用的亲水外壳组成,粒径一般为10～100nm左右。这种粒径范围的载药体系既能逃脱肾脏的排泄清除,又能躲避内皮网状系统的吞噬,延长药物在血液中的循环时间。聚合物胶束结合肿瘤靶向在化疗方面的应用,能够有效改善化疗药物的水溶性,提高化疗药物的利用率和抗肿瘤活性,降低对机体正常细胞组织的毒副作用,克服多药耐药性问题,进而极大地提高了肿瘤化疗效果和促进了肿瘤化疗的发展进步。本文着重综述聚合物胶束在化疗药物载药与靶向策略方面的研究现状与进展。     

A novel mitochondria-targeting tetrapeptide for subcellular delivery of nanoparticles

A novel mitochdrial-targeting tetrapeptide, RF-2(D-Arg-Dmt-Arg-Phe-NH₂) had been developed, which showed controlled toxicity and excellent protection against gentamicin-induced hair cell damage, and more importantly, exhibited superior guidance towards mitochondrion achieved by its modified nanoparticles.     

Co~(2+)/Dy~(3+)掺杂纳米立方Fe_3O_4的热还原制备及磁靶向滞留性能

采用热还原沉淀法制备了一系列Co~(2+)/Dy~(3+)掺杂的纳米立方MxFe3-xO4磁性颗粒.利用X射线衍射仪、透射电子显微镜和振动样品磁强计研究了不同含量掺杂离子对MxFe3-xO4晶体结构、形貌及磁性的影响.研究发现,掺杂未改变母体的对称性,但母体形貌逐渐从立方体向球体过渡;Co~(2+)和Dy~(3+)的掺杂对于铁氧体磁学性质的影响明显不同,当Co~(2+)实际掺杂量为0.44和Dy~(3+)实际掺杂量为0.05时,MxFe3-xO4立方磁性粒子的饱和磁化强度(Ms)达到最大值,分别为76.65和70.21 A·m2·kg-1.与超顺磁性Fe_3O_4球体相比,高磁性掺杂Fe_3O_4立方体在体外模拟磁流体磁靶向定位实验中显示出较高的滞留率.