Polymers with platinum drugs and other macromolecular metal complexes for cancer treatment

Metal-based anticancer drugs, in particular platinum-drugs, have been investigated for the treatment of cancer for the last 40 years. A small set of platinum-based drugs have meanwhile received FDA approval for the treatment of various cancer. Cisplatin and its relatives are currently one of the most widely used anticancer drugs. The use is however associated with significant side effects and rising drug resistance. To combat these problems, drug delivery carriers have been developed to increase the protection of the drug and increase efficacy. Metal-based drugs represent a rather unique drug delivery challenge. Most anticancer drugs are either physically encapsulated into a polymer matrix or they can be conjugated to the polymer via a degradable linker. While both pathways are possible for metal-based drugs, the conjugation to the polymer can be carried via labile or permanent ligands. In addition, the prodrug strategy using the drug in the higher oxidation state is a common approach that has been widely tested for platinum drug. The delivery of platinum drugs is now a mature field and the various conjugation techniques have been combined with a range of drug carriers including dendrimers, micelles and solid polymer nanoparticles. Hybrids of macromolecular metal complexes with inorganic nanoparticles have been tested in recent years to combine the ability to deliver the drug with imaging properties. An emerging trend is the surface decoration of the polymeric nanoparticles with targeting ligands such as folates. The advanced state of this field is evident by the fact that some macromolecular platinum drugs even advanced to the clinic. While the delivery of platinum drugs has been well explored, the delivery of other metal-based drugs based on gold, ruthenium or cobalt is still in their infancy.     

Polymer vectors via controlled/living radical polymerization for gene delivery

The design of efficient gene delivery vectors is a challenging task in gene therapy. Recent progress in living/controlled radical polymerizations (LRPs), in particular atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization providing a means for the design and synthesis of new polymeric gene vectors with well-defined compositions, architectures and functionalities is reviewed here. Polymeric gene vectors with different architectures, including homopolymers, block copolymers, graft copolymers, and star-shaped polymers, are conveniently prepared via ATRP and RAFT polymerization. The corresponding synthesis strategies are described in detail. The recent research activities indicate that ATRP and RAFT polymerization have become essential tools for the design and synthesis of advanced, noble and novel gene carriers.     

Cu/PAA纳米复合结构的制备与偏振特性研究

通过改变二次氧化过程中的氧化电压,制备了不同孔径的多孔Al(PAA)模板;采用交流电沉积的方法,制备了含Cu阳极PAA膜.X射线衍射(XRD)分析表明,阳极PAA膜上确有Cu生成;扫描电镜(SEM)显示,Cu纳米线粗细均匀,具有很好的线栅结构.Cu/PAA复合膜的透射光谱及偏振光谱表明:这种含Cu纳米线PAA膜在近红外光区有较好的透射率和消光比,且随着膜板孔径(Cu纳米线直径)的增加,样品的透射率下降而其消光比却明显提高.因此,可以通过优化模板参数,制备出实用的Cu/PAA偏振器.     

化学浆料的生物降解性分析

针对纺织生产用化学浆料对环境存在的污染问题,分析了聚乙烯醇（PVA）和聚丙烯酸（PAA）类浆料的生物降解性,提出了可通过开发可生物降解型环保浆料来解决浆料对环境污染问题的观点。     

PAA泥浆在会泽矿区水平钻孔中的应用

会泽矿区水平钻孔地层复杂,钻孔坍塌、缩径严重,试验采用PAA泥浆,取得较好效果。介绍了PAA泥浆的配方、配制方法和应用效果。     

磷酸氢钙/氨基酸共聚物生物活性复合材料

通过原位聚合法制备了磷酸氢钙/四元氨基酸共聚物(DCP/PAA)复合材料, 并采用XRD和IR方法对其组成结构进行了表征, 用模拟体液和Tris-HCl溶液分别研究了复合材料的体外生物活性和降解性能。结果表明: DCP/PAA复合材料的无机相与有机相存在着一定的相互作用; 聚合反应时间对复合材料的强度有明显的影响, 反应时间越长, PAA的黏度越大, 材料的抗压强度越高; 复合材料具有很好的生物活性, 其表面能够在模拟体液中形成磷灰石层, 新形成磷灰石的Ca与P原子比为1.59, 为缺钙磷灰石; 复合材料能够在Tris-HCl溶液中降解, PAA的黏度对复合材料在Tris-HCl中的降解有一定的影响。复合材料浸泡在Tris-HCl溶液中, 溶液的pH值在浸泡初期略有下降, 但4周后稳定在7.0~7.2, 与人体环境pH值接近。     

多孔氧化铝模板结合sol-gel旋转涂敷法制备PZT纳米管

利用溶胶-凝胶旋转涂敷法在通孔的多孔阳极氧化铝(PAA)模板中制备了锆钛酸铅(PZT)纳米管,研究了溶胶浓度对样品形貌的影响。利用SEM和TEM观察了纳米管阵列和单根纳米管的形貌,采用XRD和EDS图谱分析了纳米管的相结构和化学元素组成。结果表明合成的PZT纳米管结晶良好,具有钙钛矿结构(属于四方晶系);纳米管具有较高的韧性但表面较粗糙,直径和管壁厚度分别约为75和7nm,直径与原始PAA模板的孔径相吻合。在一定范围内调节PZT溶胶的浓度(0.1～0.4mol/L),均能在PAA模板的孔洞中形成PZT多晶纳米管,且组成PZT纳米管的晶粒随着溶胶浓度的增加而变大。     

模拟压水堆(PWR)二回路条件下添加分散剂对结构材料腐蚀行为的影响

采用高温高压腐蚀试验研究了分散剂聚丙烯酸(PAA)对设备材料A508III和A106Gr.B在模拟压水堆二回路水溶液中腐蚀行为的影响。利用扫描电镜、俄歇光电子能谱表征了腐蚀后氧化膜的微观形貌及成分。结果表明:随PAA含量的增多,A508III和A106Gr.B试样的腐蚀失重逐渐增大,浸泡液中铁含量也随PAA含量的递增呈升高趋势;2 000h腐蚀试验后,与无PAA工况相比,A508III和A106Gr.B试样的腐蚀速率分别下降21.58%和8%;在分散剂作用下,A508III试样氧化膜表面颗粒物结晶度下降,氧化膜更薄;PAA分散剂与A106Gr.B试样有较好的相容性且对A508III试样有一定的缓蚀作用。     

The chemistry of tissue adhesive materials

Each year millions of people sustain traumatic or surgical wounds, which require proper closure. Conventional closure techniques, including suturing and stapling, have many disadvantages. They inflict additional damage on the tissue, elicit inflammatory responses and have a relatively long application time. Especially for the more demanding wounds, where fluids or gasses are to be sealed off, these techniques are often insufficient. Therefore, a large variety of tissue adhesives, sealants and hemostatic agents have been developed. This review provides an overview of such tissue adhesive materials from a polymer chemistry perspective. The materials are divided into synthetic polymer, polysaccharide and protein based adhesives. Their specific properties and behavior are discussed and related to their clinical application. Though each type has its specific advantages, yet few have become standard in clinical practice. Biomimetic based adhesives and other novel products have shown promising results but also face specific problems. For now, the search for better adhering, stronger, easier applicable and cheaper adhesives continues and this review is intended as starting point and inspiration for these future research efforts to develop the next generation tissue adhesives.     

Re‐Engineering Poly(Acrylic Acid) Binder toward Optimized Electrochemical Performance for Silicon Lithium‐Ion Batteries: Branching Architecture Leads to Balanced Properties of Polymeric Binders

Silicon is a promising anode material for lithium‐ion batteries with its superior capacity. However, the drastic volume changes during lithiation/delithiation cycles hinder the cycling performance, resulting in particle pulverization, conductivity loss, and an unstable electrode–electrolyte interface. Herein, a series of synthetic polymeric binders, poly(acrylic acid‐co‐tetra(ethylene glycol) diacrylate)—featuring a poly(acrylic acid) (PAA) backbone branched via tetra(ethylene glycol) diacrylate (TEGDA)—are developed that edge toward evidencing well‐balanced properties to confront capacity fading in Si‐based electrodes. The incorporation of ether chain not only leads to the branching architecture of the PAA backbone, thus affecting its mechanical properties, but also promotes the conductivity of Li ions. As a result, a synergistic performance improvement is observed in both half and full cells. The best‐performing cell using a branched PAA binder (bPAA) with a feeding molar ratio ([TEGDA]:[acrylic acid(AA)]) of 0.2 results in a 10% increase in initial capacity and a 31% increase in capacity retention over 100 cycles compared to the linear PAA cell. The cross‐sectional microscopic images of the cycled electrodes reveal that bPAA binders can drastically reduce the electrode expansion. This improvement results from the well‐balanced properties of the polymer design, which could guide further development for more advanced binder materials.