Multifunctional Non‐Viral Delivery Systems Based on Conjugated Polymers

Multifunctional nanomaterials with simultaneous therapeutic and imaging functions explore new strategies for the treatment of various diseases. Conjugated polymers (CPs) are considered as novel candidates to serve as multifunctional delivery systems due to their high fluorescence quantum yield, good photostability, and low cytotoxicity. Highly sensitive sensing and imaging properties of CPs are well reviewed, while the applications of CPs as delivery systems are rarely covered. This feature article mainly focuses on CP‐based multifunctional non‐viral delivery systems for drug, protein, gene, and cell delivery. Promising directions for the further development of CP‐based delivery systems are also discussed.

     

Controllable synthesis of well-ordered TiO2 nanotubes in a mixed organic electrolyte for high-efficiency photocatalysis

Well-ordered TiO 2 nanotube arrays (TNAs) were fabricated by electrochemical anodization in a mixed organic electrolyte consisting of ethylene glycol and glycerol. The morphology, structure, crystalline phase, and photocatalytic properties of TNAs were characterized by using TEM, SEM, XRD and photodegradation of methylene blue. It was found that the morphology and structure of TNAs could be significantly influenced by the anodization time and applied voltage. The obtained tube length was found to be proportional to anodization time, and the calculated growth rate of nanotubes was 0.6 m/h. The microstructure analysis demonstrated that the diameter and thickness of the nanotubes increased with the increase of anodization voltage. The growth mechanism of TNAs was also proposed according to the observed relationship between current density and time during anodization. As expected, the obtained TNAs showed a higher photocatalytic activity than the commercial TiO 2 P25 nanoparticles.     

Bridged polyhedral oligomeric silsesquioxane (POSS): A potential member of silsequioxanes

Two novel and well-defined polyhedral oligomeric silsesquioxanes（POSS） with two same Si₈O₁₂ cores and a reactive NH group, namely bridged-POSS（2a and 2b）,have been prepared by the traditional ’corner-capping’ reaction.X-ray diffraction demonstrates that those two POSS have the similar T₈ structure.From the thermo-gravimetric analysis,bridged-POSS shows the belter thermal degradation stability than the contrastive POSS.     

Novel organosoluble polyimide based on an asymmetric bis(ether amine): 3, 4′-Bis(4-aminophenoxy)-benzophenone

A new kind of asymmetrical ether diamine,3,4’-bis（4-aminophenoxy）benzophenone（BABP）,was synthesized from the nucleophilic substitution reaction of 4-chloronitrobenzene and 3,4’-dihydroxybenzophenone in the presence of potassium carbonate,followed by catalytic reduction with SnCl₂-6H₂O and concentrated hydrochloric acid.The prepared diamine was employed in the preparation of a novel polyimide containing asymmetrical diaryl ether segments via the polycondensation of it with BTDA by a two-step method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.     

新型水溶性超支化聚酰胺-酯的合成

均苯四甲酸酐与二乙醇胺经酰化反应制得中心核(4);4与AB2单体2,2-二羟甲基丙酸经熔融缩聚合成了一种新型水溶性的二代超支化聚酰胺-酯(1),其结构与性能经FT-IR,GPC,粘度法,化学滴定等表征。4的Mn=1 683,Mw=1 911,Mw/Mn=1.14,[ηinh]=0.067 6 dL·g-1;1的Mn=3 750,Mw=4 904,Mw/Mn=1.31,[ηinh]=0.086 1 dL·g-1。     

Catalytic Asymmetric Dearomatization Reactions

This Review summarizes the development of catalytic asymmetric dearomatization (CADA) reactions. The CADA reactions discussed herein include oxidative dearomatization reactions, dearomatization by Diels–Alder and related reactions, the alkylative dearomatization of electron‐rich arenes, transition‐metal‐catalyzed dearomatization reactions, cascade sequences involving asymmetric dearomatization as the key step, and nucleophilic dearomatization reactions of pyridinium derivatives. Asymmetric dearomatization reactions with chiral auxiliaries and catalytic asymmetric reactions of dearomatized substrates are also briefly introduced. This Review intends to provide a concept for catalytic asymmetric dearomatization.     

Synthesis and evaluation of oxovanadium(iv) complexes of Schiff-base condensates from 5-substituted-2-hydroxybenzaldehyde and 2-substituted-benzenamine as selective inhibitors of protein tyrosine phosphatase 1B

Five oxovanadium(iv) complexes, which were divided into two groups, [V(IV)O(bhbb, nhbb)(H(2)O)(2)] (tridentate ligands: H(2)bhbb = 2-(5-bromo-2-hydroxylbenzylideneamino)benzoic acid, ; H(2)nhbb = 2-(5-nitro-2-hydroxylbenzylideneamino)benzoic acid, ) and [V(IV)O(cpmp, bpmp, npmp)(2)] (bidentate ligands: Hcpmp = 4-chloro-2-((phenylimino)methyl)phenol, ; Hbpmp = 4-bromo-2-((phenylimino)methyl)phenol, ; Hnpmp = 4-nitro-2-((phenylimino)methyl) phenol, ) have been prepared and characterized by elemental analysis, infrared, UV-visible and electrospray ionization mass spectrometry. The coordination in [V(IV)O(bhbb)(H(2)O)(2)] () was confirmed by X-ray crystal structure analysis. The oxidation state of V(iv) with d(1) configuration in was confirmed by EPR. The speciation of VO/H(2)bhbb in methanol-aqueous solution was investigated by potentiometric pH titrations. The result indicated that the main species were [V(IV)O(bhbb)(OH)](-) and [V(IV)O(bhbb)(OH)(2)](2-) at the pH range 7.0-7.4. The structure-activity relationship of the vanadium complexes in inhibiting protein tyrosine phosphatases (protein tyrosine phosphatase 1B, PTP1B; T-cell protein tyrosine phosphatase, TCPTP; megakaryocyte protein-tyrosine phosphatase, PTP-MEG2; Src homology phosphatase 1, SHP-1 and Src homology phosphatase 2, SHP-2) was investigated. The oxovanadium(iv) complexes were potent inhibitors of PTP1B, TCPTP, PTP-MEG2, SHP-1 and SHP-2, but exhibited different inhibitory abilities over different PTPs. Complexes and displayed better selectivity to PTP1B over the other four PTPs. Kinetic data showed that complex inhibited PTP1B, TCPTP and SHP-1 with a noncompetitive inhibition mode, but a classical competitive inhibition mode for PTP-MEG2 and SHP-2. The results demonstrated that both the structures of vanadium complexes and the conformations of PTPs influenced PTP inhibition activity. The proper modification of the organic ligand moieties may result in screening potent and selective vanadium-based PTP1B inhibitors.