偶氮苯基两亲性聚合物的自组装行为研究进展

偶氮苯基两亲性聚合物结合了偶氮苯基团的光响应、酶响应、主客体识别特性和两亲性聚合物的自组装特性,能够在选择性溶剂中发生聚合物可控自组装行为,这使得其在药物控释、纳米技术和生物医学材料等领域受到了广泛的关注。本文从结构类型和合成方法出发,综述了新型偶氮苯基两亲性聚合物在溶液中的自组装研究进展,并对该领域的发展前景进行了展望。     

两亲性多肽自组装及其应用

两亲性多肽分子具有类似天然磷脂分子的两亲特性、丰富的分子结构、独特新颖的组装体结构以及特殊的生物学功能,是多肽自组装研究的热点领域.本文总结了近年来关于两亲性多肽自组装研究及应用的进展,介绍了几种常见的两亲性多肽,并进一步阐述其分子结构特征、组装行为和机理、组装体结构和功能以及在纳米技术和生物医学领域中的应用.     

两亲性笼型倍半硅氧烷（POSS）杂化高分子的自组装

笼型倍半硅氧烷（POSS）是一种由si-O-si键构成的高度对称笼型结构、端基具有极高的可设计性及高反应性新型有机一无机杂化材料,空间尺寸1～3nm;选取带有特定结构的光、电、磁等特性单元,利用活性聚合的方法可制得不同形状的POSS-Polymer杂化材料,通过溶剂、热、电、纳米印刷等方法“梳理”分子链结构,使之成为长程有序的纳米序列结构材料,获取具有预期结构和功能特性的高分子实体。本文从分子自组装的角度对两亲性笼型倍半硅氧烷（POSS）杂化高分子材料进行了介绍,分析了其在生物医药用高分子、智能高分子及低介电高分子材料等多个领域内的最新研究进展,并对今后的发展做了相关的预测与展望。     

两亲性卟啉-紫精化合物LB膜的结构及光电性质研究

本文制备了两亲性卟啉-紫精化合物的LB膜材料, 用π-A等温曲线、吸收光谱、小角和低角X射线衍射以及扫描隧道电镜(STM)等方法研究了LB膜的结构。结果表明, LB膜内分子排列是二维有序的超晶格结构, 卟啉环在基片上的排列呈"站立"状态。单个分子占有面积为1.15nm^2, 单层高度为2.35nm, 相邻裂间的距离为1.07nm。这种规则有序的两亲性卟啉-紫精化合物呈现出良好的光量子收率和光电响应特性。     

两亲性共聚物的分子设计与合成及其共混膜性能

从分子结构设计出发,采用自由基聚合、醚化、酯化、原子转移自由基聚合(ATRP)、可逆加成断裂链转移自由基聚合(RAFT)等方法合成了一系列具有不同分子结构(包括接枝、嵌段、交替、超支化等)和链形态(包括直链、梳状、哑铃状、链球状等)的两亲性共聚物,并对这些聚合物进行了谱学表征和性能测试.将这些两亲性共聚物与聚合物膜材料(包括聚偏氟乙烯、聚氯乙烯、聚砜、聚醚砜、聚醚砜酮等)进行溶液共混,通过相转化法制备共混膜,在成膜热力学和动力学分析的基础上,对共混膜的结构和性能进行调控.研究发现,两亲性共聚物在成膜过程中自发地向膜表面迁移富集,并进行自组装,在膜表面形成两亲性共聚物包膜,显著改善了聚合物多孔膜的亲水性和抗污染性能.此外,两亲性共聚物中的功能基团还可赋予共混膜某些功能特性,如生物相容性、环境响应性(pH、温度敏感性)、酶活性等.     

两亲性Janus粒子的合成及其在Pickering乳液中的应用

Janus粒子由于在光、电、力、磁及表面亲/疏水性等方面表现出各向异性,因此在稳定乳液、生物医药及功能涂层等方面展现出广阔的应用价值。两亲性Janus粒子是指一侧具有亲水性、另一侧具有疏水性的不对称材料,由于同时具有表面活性剂的性质和固体颗粒的效应,在稳定Pickering乳液方面极具优势。基于此,本文对两亲性Janus粒子的制备方法进行了综述,并对比分析了其优缺点,同时总结了两亲性Janus粒子对Pickering乳液稳定性的影响,最后对其今后的发展进行了展望。     

聚乙二醇在新型药物制剂中的应用

聚乙二醇具有良好的生物相容性和两亲性 ,在生物医药领域中有着广泛的应用 ,本文就聚乙二醇在新型药物制剂中的应用进行综述 ,主要包括纳米给药系统、蛋白质药物修饰和疏水性药物的前药等。     

嵌段共聚物薄膜在电化学能源领域的应用

采取选择性掺杂方法,将新型两亲性液晶嵌段共聚物薄膜功能化为具有各向异性的锂离子导电材料.这类薄膜不仅具有同轴且垂直取向的一维离子导电通道,而且可以在大面积范围内形成规则的阵列,可以作为锂离子电池、燃料电池等电化学能源系统的新型电解质.另一方面,这类薄膜作为模板可制备周期性排列的纳米孔、纳米粒子、纳米线阵列,形成的有序纳米结构材料可作为锂离子电池的三维电极.     

两亲性超支化聚合物的研究进展

两亲性超支化聚合物作为一种新型功能性材料.近年来引起了人们的广泛关注.两亲性超支化聚合物的合成丰要是利用不同亲水性的链段对超支化聚合物端基进行改性,或者首先在超支化聚合物末端产生活性位点,再利用超支化分f作为大分子引发剂引发烯类单体进行斤环聚合、原子转移自由基聚合等得到以超支化聚合物为核的两亲性超支化共聚物;这些分子由...     

聚乙烯基吡咯烷酮的可控制备及在紫杉醇药物递送体系中的应用

紫杉醇是一种有效的具有抗癌特性的天然化合物,但其自身的疏水性导致了临床应用的限制,为了解决这一问题,人们通常使用两亲性聚合物作为其药物递送的载体,以达到有效的药物包封和高效的药物递送。作为水溶性高分子的聚乙烯吡咯烷酮,因其具有优异的亲水性与生物相容性,常被用于与疏水链段结合形成两亲性共聚物,应用于紫杉醇药物递送系统。本文综述了近年来聚乙烯吡咯烷酮及其嵌段共聚物的可控制备方法,总结了其在紫杉醇药物缓释体系中的应用研究成果,并对综合性能更加优异的紫杉醇药物缓释载体的构建进行了展望。     

Azo Polymer Janus Particles Possessing Photodeformable and Magnetic‐Field‐Responsive Dual Functions

It is of great fundamental and practical significance to endow Janus particles with various field‐responsive properties. In this study, a new strategy with a wide range of application possibilities is developed to fabricate JPs composed of a methacrylate‐based azo polymer, polystyrene, and Fe₃O₄ nanoparticles. The JPs are obtained through microphase separation in a confined volume of the dispersed droplets. The azo polymer and PS are incorporated in JPs in a core‐compartmentalized manner, and Fe₃O₄ are proved to exist in the azo polymer phase. The JPs show responsive movement in the magnetic field and can be easily oriented with the help of the field. By variation of the intersection angle between the particle symmetrical axis and the polarization direction of the linearly polarized laser beam, different deformation modes are feasibly achieved for the JPs. By exploiting the dual‐responsive properties, JPs with designed shapes can be fabricated by exposing the JPs to linearly polarized light.     

Azo‐Polymer Janus Particles Assembled by Solvent‐Induced Microphase Separation and Their Photoresponsive Behavior

We report the successful fabrication of photoresponsive Janus particles (JPs) composed of an epoxy‐based azo polymer and poly(methyl methacrylate) (PMMA). Two representative azo polymers, of which one polymer (BP‐AZ‐CN) has cyano groups as electron‐withdrawing substituents on the azobenzene moieties and the other polymer (BP‐AZ‐CA) has carboxyl groups as the electron‐withdrawing substituents, were adopted for the investigation. The nanoscaled JPs, with a narrow size distribution and different azo polymer/PMMA ratios, were fabricated through self‐assembly in solution and as dispersions. Upon irradiation with linearly polarized light (λ=488 nm), two types of photoresponsive behavior were observed for JPs in the solid state. For JPs composed of BP‐AZ‐CN and PMMA, the light irradiation caused the azo‐polymer component to be stretched along the light polarization direction. Conversely, for JPs composed of BP‐AZ‐CA and PMMA, the azo‐polymer component became separated from PMMA component under the same irradiation conditions. These observations are valuable for a deeper understanding of the nature of self‐assembly and photoinduced mass‐transport at the nanometer scale.     

Janus and ternary particles generated by microfluidic synthesis: design, synthesis, and self-assembly

This paper reports a microfluidic method for fast continuous synthesis of Janus particles and three-phase particles with narrow size distribution. Synthesis of particles included emulsification of monomer liquids and in-situ photoinitiated polymerization of multiphase droplets. We show the strategy for precise control over the structure of Janus particles and their structure-dependent assembly in clusters. We demonstrate an asymmetric chemical modification of the surface of JPs by conjugating them with protein molecules. The Janus and ternary particles were synthesized from largely immiscible liquids and had a sharp interface between the constituent phases.     

Biofunctional Janus particles promote phagocytosis of tumor cells by macrophages

Herein, a versatile strategy for the construction of biofunctional Janus particles (JPs) through the combination of Pickering emulsion and copper-free click chemistry is developed for the study of particle-mediated cell–cell interactions. A variety of biomolecules including bovine serum albumin (BSA), ferritin, transferrin (Tf), and anti-signal regulatory protein alpha antibodies (aSIRPα), etc., can be incorporated into the Janus platform in a spatially defined manner. JPs consisting of Tf and aSIRPα (Tf–SPA1–aSIRPα JPs) demonstrate a significantly improved binding affinity to either macrophages or tumor cells compared to their uniformly modified counterparts. More importantly, Tf–SPA1–aSIRPα JPs mediate more efficient phagocytosis of tumor cells by macrophages as revealed by real-time high-content confocal microscopy. This study demonstrates the potential advantages of JPs in mediating cell–cell interactions and may contribute to the emerging cancer immunotherapy.

A versatile Janus particle platform modified with biological ligands can facilitate tumor cell phagocytosis by macrophages for promising cancer immunotherapy.     

非对称性Janus粒子的制备与可控组装

古罗马的双面神(Janus)常被用来描述具有两种不同化学结构或性质的不对称粒子, Janus粒子由于自身的特殊性能在药物载体、电子器件和乳液稳定等方面表现出良好的发展势头, 其应用前景日益受到人们的重视. 目前, Janus 粒子作为基本的组装基元受到越来越多的关注, 相关组装方法也被广泛地研究, 包括本体组装、界面组装和外界驱动力调控等, 特别是Janus 粒子的双亲修饰与功能化. 本文综述了现今Janus 粒子制备方法及对其进行修饰组装的最新研究进展, 详细讨论比较了一步合成法、聚合物自组装法和晶种直接生长等方法的特点及差异, 并对一些新型功能Janus粒子的设计及潜在的应用前景进行了展望.     

Janus Nanoparticles: Preparation,Characterization, and Applications

In chemical functionalization of colloidal particles, the functional moieties are generally distributed rather homogeneously on the particle surface. Recently, a variety of synthetic protocols have been developed in which particle functionalization may be carried out in a spatially controlled fashion, leading to the production of structurally asymmetrical particles. Janus particles represent the first example in which the two hemispheres exhibit distinctly different chemical and physical properties, which is analogous to the dual‐faced Roman god, Janus. Whereas a variety of methods have been reported for the preparation of (sub)micron‐sized polymeric Janus particles, it has remained challenging for the synthesis and (unambiguous) structural characterization of much smaller nanometer‐sized Janus particles. Herein, several leading methods for the preparation of nanometer‐sized Janus particles are discussed and the important properties and applications of these Janus nanoparticles in electrochemistry, sensing, and catalysis are highlighted. Some perspectives on research into functional patchy nanoparticles are also given.     

双面神粒子制备的研究进展

双面神粒子描述的是一类各向异性的、粒子的两个半球表面具有不同化学性质的微粒.它结构特殊,性能优异,应用前景广阔.本文综述了双面神粒子制备及其性能研究的进展,并对今后的发展作了展望.     

Facile, solution-based synthesis of soft, nanoscale janus particles with tunable janus balance

We present a novel, versatile, and simple solution-based routine to produce soft, nanosized Janus particles with tunable structural and physical properties at high volume yield. This process is based on the cross-linking of compartments within precisely defined multicompartment micelles (MCMs), which are themselves formed by the self-assembly of ABC triblock terpolymers. Therein, the C blocks form the stabilizing corona emanating from B compartments, which in turn reside on an A core. Cross-linking of the B compartments allows to permanently fixate the phase-separated state and dissolution in a good solvent for all blocks breaks up the MCMs into single Janus particles. They now consist of a core of cross-linked B blocks and two phase-separated hemispheres of A and C. The process gives access to unprecedented structural features such as tunable core diameter and control over the Janus balance ranging from dominant A side to equal hemispheres to dominant C side. We demonstrate that this simple one-pot approach can be extended to a range of triblock terpolymers with different block lengths and block chemistries to furnish a library of tailor-made Janus particles with widely tunable physical properties. Such a diversity and simplicity has remained unreachable with our previously developed approach using the controlled cross-linking of bulk morphologies. We show that this new synthetic route can be upscaled to a high volume yield of 10 wt %, thereby enabling large-scale applications. We further demonstrate the effect of the Janus balance on colloidal self-assembly. Janus particles with a dominant hydrophobic and a small hydrophilic patch aggregate into large clusters in water, but merely di- or trimerize in chloroform.     

Bifunctional Janus microparticles with spatially segregated proteins

We present a fabrication process to create bifunctional microparticles displaying two distinct proteins that are spatially segregated onto the surface hemispheres. Silica and polystyrene microparticles with 2.0, 4.1, and 4.7 μm diameters are processed with metal deposition to form two chemically distinct and segregated hemispheres. The surface of each hemisphere is then separately derivatized with biological proteins using different chemical conjugation strategies. These bifunctional Janus particles possess biologically relevant, native conformation proteins attached to a biologically unreactive and safe substrate. They also display high densities of each type of protein which may enable a range of capabilities that monofunctional particles cannot, such as improved targeting of drugs and bioimaging agents.     

Polymer particles with various shapes and morphologies produced in continuous microfluidic reactors

We report a novel approach to continuous and scalable production of core-shell droplets and polymer capsules in microfluidic devices. The described method is also useful in the synthesis of polymer particles with nonspherical shapes. We used capillary instability-driven break-up of a liquid jet formed by two immiscible fluids. Precise control of emulsification of each liquid allowed for the production of highly monodisperse core-shell droplets with a predetermined diameter of cores and thickness of shells. We also achieved control over the number of cores per droplet and the location of cores in the droplet. We carried out fast throughput photopolymerization of the monomeric shells and obtained polymer particles with various shapes and morphologies, including spheres, truncated spheres and, hemispheres, and single and multicore capsules.