新型高聚物聚亚胺酮-Ⅱ(PIK-Ⅱ)的合成与性能

通过傅-克酰基化反应合成了1,4-双-(4′-溴苯酰基)苯,以1,4-双-(4′-溴苯酰基)苯和4′4-二氨基二苯醚为单体,通过钯催化的胺基化缩聚反应合成了高性能聚合物——聚亚胺酮-Ⅱ(PIK-Ⅱ)。由红外和核磁氢谱等表征了PIK-Ⅱ结构,表征结果与目标结构相吻合。采用DSC和TG等对PIK-Ⅱ的主要性能进行了测定。结果表明,该聚合物表现出较高的玻璃化转变温度(Tg>240℃)、良好的热稳定性(热分解温度TD>540℃)及优良的的溶解性能。     

新型荧光材料二水合-[N,N,-双(2-苯胺基)乙二酰胺] 合锌的合成与表征

合成了新型荧光材料二水合-[N,N,-双(2-苯胺基)乙二酰胺]合锌,并用元素分析、红外、紫外、核磁共振等进行了表征,通过对其荧光性能的研究,证明该化合物是一种较好的新型荧光材料。     

针铁矿吸附水中硫酸根离子的试验研究

利用合成的针铁矿对水中硫酸根离子进行吸附试验。试验表明，吸附量主要受pH值和硫酸根离子浓度影响。通过配位体交换理论，很好地解释了吸附量随pH下降而增加，随硫酸根离子浓度的下降而减少。     

Genetically Engineered Liposome‐like Nanovesicles as Active Targeted Transport Platform

Ligand‐targeted delivery of drug molecules to various types of tumor cells remains a major challenge in precision medicine. Inspired by the secretion process and natural cargo delivery functions of natural exosomes, biomimetic synthetic strategies are exploited to prepare biofunctionalized liposome‐like nanovesicles (BLNs) that can artificially display a wide variety of targeting protein/peptide ligands and directly encapsulate medical agents for enhanced drug delivery. Here, as a proof of concept, genetically engineered BLNs, which display human epidermal growth factor (hEGF) or anti‐HER2 Affibody as targeting moieties, are developed to, respectively, target two types of tumor cells. Notably, in comparison to synthetic liposomes covalently coupled with hEGF, it is demonstrated in this work that biosynthetically displayed hEGF ligands on BLNs possess higher biological activities and targeting capabilities. Additionally, treatments with doxorubicin‐loaded BLNs displaying Affibody ligands exhibit much better antitumor therapeutic outcomes than clinically approved liposomal doxorubicin (Doxil) in HER2‐overexpressing BT474 tumor xenograft models. These data suggest that BLN is suitable as a potent surrogate for conventional proteoliposomes or immunoliposomes as a result of excellent targeting capacities and facile production of BLNs.     

Role of Surface RGD Patterns on Protein Nanocages in Tumor Targeting Revealed Using Precise Discrete Models

The effectiveness of active targeting in cancer nanomedicine is becoming increasingly more debatable. Here, the role of the ligand functionalization patterns (number and distribution) on nanoparticle surfaces in tumor targeting is investigated using a 9 nm sized miniferritin protein nanocage, Dps modified with Arg‐Gly‐Asp (RGD) ligands whose functionalization patterns are precisely controlled. In vitro and in vivo experiments show that RGD modification endows Dps with tumor targeting capacity no matter what the surface pattern is. The tumor targeting of 2‐ligand Dps, which is better than that of 1‐ligand Dps, rivals or surpasses that of the 12‐ or 24‐ligand Dps. The 12‐ligand Dps with clustered RGD distribution shows 2.3 times the in vivo targeting efficiency of that with even distribution. The surface ligand pattern effects are correlated at least to receptor clustering and opsonization. This study provides insights into the understanding of the controversial findings on active tumor targeting in the literature and highlights the necessity of precise functionalization to achieve optimal active targeting in developing cancer nanomedicine.     

Engineering Bimetal Synergistic Electrocatalysts Based on Metal–Organic Frameworks for Efficient Oxygen Evolution

Benefiting from metal–organic frameworks (MOFs) unique structural characteristics, their versatility in composition and structure has been well explored in electrochemical oxygen evolution reaction (OER) processes. Here, a ligand/ionic exchange phenomenon of MOFs is reported in alkaline solution due to their poor stability, and the active species and reaction mechanism of MOFs are revealed in the OER process. A series of mixed Ni‐MOFs and Fe‐MOFs are synthesized by straightforward sonication and then directly used as catalyst candidates for OER in alkaline electrolyte. It can be confirmed via ex situ transmission electron microscopic images and X‐ray diffraction patterns analysis, that the bimetallic hydroxide (NiFe‐LDH) is generated in 1.0 m KOH in situ and acts as protagonist for oxygen evolution. The optimized catalyst (FN‐2) exhibits a lower overpotential (275 mV at a current density of 10 mA cm^?2) and excellent long‐term stability (strong current density for 100 h without fading). The revelation of the real active species of MOF materials may contribute to better understanding of the reaction mechanism.     

含半不稳定边臂配体的钛配合物催化丙交酯聚合

聚乳酸类材料作为可生物降解性材料具有广阔的应用前景。设计、合成了6种含半不稳定边臂的希夫碱配体L1—L6,并与钛酸四异丙酯络合合成相应的6种配合物C1—C6,配合物的结构和化学组成经元素分析、红外测试确定。将其作为催化剂催化丙交酯开环聚合,以催化剂C1为考察对象,系统研究了催化剂用量、温度、时间对聚合反应的影响,发现当单体与催化剂配比为2 000,温度为160℃,反应24h时,聚合产率最高,达90.35%,聚合物分子量达8.41×104。在上述优化条件下,比较了催化剂C1—C6的活性,结果表明催化剂活性按以下顺序递减:C6C4C3C1C2C5,同时,催化剂中心金属钛原子周围位阻相对稍小,配体中含配位能力较弱的半不稳定O边臂均有利于提高催化剂的活性。     

Quantified Binding Scale of Competing Ligands at the Surface of Gold Nanoparticles: The Role of Entropy and Intermolecular Forces

A basic understanding of the driving forces for the formation of multiligand coronas or self‐assembled monolayers over metal nanoparticles is mandatory to control and predict the properties of ligand‐protected nanoparticles. Herein, ¹H nuclear magnetic resonance experiments and advanced density functional theory (DFT) modeling are combined to highlight the key parameters defining the efficiency of ligand exchange on dispersed gold nanoparticles. The compositions of the surface and of the liquid reaction medium are quantitatively correlated for bifunctional gold nanoparticles protected by a range of competing thiols, including an alkylthiol, arylthiols of varying chain length, thiols functionalized by ethyleneglycol units, and amide groups. These partitions are used to build scales that quantify the ability of a ligand to exchange dodecanethiol. Such scales can be used to target a specific surface composition by choosing the right exchange conditions (ligand ratio, concentrations, and particle size). In the specific case of arylthiols, the exchange ability scale is exploited with the help of DFT modeling to unveil the roles of intermolecular forces and entropic effects in driving ligand exchange. It is finally suggested that similar considerations may apply to other ligands and to direct biligand synthesis.     

Ligand‐Free Fe3O4/CMCS Nanoclusters with Negative Charges for Efficient Structure‐Selective Protein Adsorption

The easy and effective capture of a single protein from a complex mixture is of great significance in proteomics and diagnostics. However, adsorbing nanomaterials are commonly decorated with specific ligands through a complicated and arduous process. Fe₃O₄/carboxymethylated chitosan (Fe₃O₄/CMCS) nanoclusters are developed as a new nonligand modified strategy to selectively capture bovine hemoglogin (BHB) and other structurally similar proteins (i.e., lysozyme (LYZ) and chymotrypsin (CTP)). The ligand‐free Fe₃O₄/CMCS nanoclusters, in addition to their simple and economical two‐step preparation process, possess many merits, including uniform morphology, high negative charges (?27 mV), high saturation magnetization (60 emu g^?1), and high magnetic content (85%). Additionally, the ligand‐free Fe₃O₄/CMCS nanoclusters are found to selectively capture BHB in a model protein mixture even within biological samples. The reason for selective protein capture is further investigated from nanomaterials and protein structure. In terms of nanomaterials, it is found that high negative charges are conducive to selectively adsorb BHB. In consideration of protein structure, interestingly, the ligand‐free magnetic nanoclusters display a structure‐selective protein adsorption capacity to efficiently capture other proteins structurally similar to BHB, such as LYZ and CTP, showing great potential of the ligand‐free strategy in biomedical field.