Lactose-appended schizophyllan is a potential candidate as a hepatocyte-targeted antisense carrier

A schizophyllan (beta-1,3-glucan) derivative carrying lactose-appendages prepared by reductive amination can form stable macromolecular complexes with polynucleotides, shows excellent affinity with a lactose-binding lectin, and effectively mediates gene transfection into hepatocytes.     

Chemical modification of schizophyllan by introduction of a cationic charge into the side chain which enhances the thermal stability of schizophyllan-poly(C) complexes

Combining oxidation with periodate and reductive amination, the amino group is introduced only in the side chain of schizophyllan and the product can bind to poly(C) with a higher dissociation temperature than that of the unmodified schizophyllan and poly(C) complex.     

Novel DNA-Polysaccharide Triple Helixes and Their Application to a Gene Carrier

Schizophyllan is a polysaccharide that belongs to the β-(1 → 3)-glucanfamily and has been known to activate the immunity system. This paper reviews our recent finding that schizophyllan can form a macromolecular complex with single-stranded polynucleotides and this complex is applicable to a new class of gene carriers.     

Photochemistry of macromolecular metal complexes. III. Synthesis,spectral and electrochemical properties of macromolecular bound protoporphyrin in aqueous solution

The macromolecular bound protoporphyrin IX and its metal complexes, poly-(protoporphyrin-co-acrylamide), cobalt(II) [poly(protoporphyrin-co-acrylamide)], zinc-(II)[poly(protoporphyrin-co-acrylamide)], and manganese(III) [poly(protoporphyrin-co-acrylamide)] chloride were synthesized. The absorption and emission spectra have been obtained for the macromolecular porphyrins. The lifetime of the excited singlet state of the protoporphyrin IX was found to decrease from 13.7 to 6.2 ns after polymerization. The cyclic voltammograms of polymeric protoporphyrin coated electrodes have been obtained. © 1992 John Wiley & Sons, Inc.     

Poly(diacetylene)-nanofibers can be fabricated through photo-irradiation using natural polysaccharide schizophyllan as a one-dimensional mold

Schizophyllan interacts with various 1,4-diphenylbutadiyne derivatives to induce their chirally-twisted packing. A series of referential experiments using other polysaccharides (amylose, pullulan, dextran, etc.) and a carbohydrate-appended detergent (dodecyl-beta-d-glucopyranoside) indicates that these 1,4-diphenylbutadiyne derivatives are accommodated within a tubular cavity constructed by a helical superstructure of schizophyllan. In these 1,4-diphenylbutadiyne derivatives, 1,4-bis(p-propionamidophenyl)butadiyne can be easily polymerized through UV-irradiation, in which schizophyllan acts as a one-dimensional mold to produce the corresponding poly(diacetylene)s with fibrous morphologies. Detailed investigations on this unique approach to prepare the nanofibers revealed that it includes two individual processes, that is, 1) UV-mediated polymerization of encapsulated 1,4-bis(p-propionamidophenyl)butadiyne to produce immature nanofibers and 2) their reorganization through hydrophobic interfiber interactions into ordered nanofibers. The other 1,4-diphenylbutadiyne derivatives could not be polymerized through UV-irradiation, indicating that the p-propionamido-functionalities play substantial roles for a suitable packing of the monomer for the polymerization. The other 1,4-diphenylbutadiyne derivatives, however, can be also polymerized through gamma-ray irradiation in the presence of schizophyllan to give the corresponding poly(diacetylene)-nanofibers, emphasizing the wide applicability of the schizophyllan-based strategy for polymerization of various 1,4-diphenylbutadiyne derivatives.     

Synthetic immunogen for the anti-relapse treatment of opioid dependence

A synthetic immunogen representing a complex of a conjugate of a macromolecular carrier (natural protein) and a hapten (morphine drug) covalently bound to poly(4-nitrophenyl acrylate) (PNPA) has been developed. The macromolecular carrier in the conjugate is a human serum protein (human gamma-globulin, HGG, or human serum albumin, HSA). The optimal design of the synthetic immunogen was developed. The epitope accessibility and specificity of the immunogen complexes were investigated by ELISA. It was established that antigenic determinants are not shielded upon binding to antibodies for complexes with the optimal (1: 10) ratio of the conjugate to the synthetic polymer. The accute toxicity of PNPA was estimated. The immunogenicity of synthetic complexes was studied in rat immunization models. An influence of the immunogen structure and vaccination dose on the ability to produce specific antibodies to morphine was found.     

Chirality control in oligothiophene through chiral wrapping

[structure: see text] Mixing oligothiophenes and polysaccharides, such as amylose and schizophyllan, affords novel inclusion complexes, in which oligothiophene guests adopt twisted conformation in the chiral channel created by left- or right-handed helical wrapping with the polysaccharide host polymers, leading to optical activity.     

Fabrication of fluorescent holographic micropatterns based on the rare earth complexes using azobenzene‐containing poly(aryl ether)s as macromolecular ligands

In this work, on the basis of photoinduced surface relief gratings (SRGs) with the rare earth complexes using azo‐polymers as macromolecular ligands, a series of novel materials for fabricating rewritable fluorescent two‐dimensional micropatterns, whose color can be easily adjusted by changing the species of the rare earth ions, are demonstrated. The rare earth complexes are prepared using a series of poly(aryl ether)s containing azobenzene chromophores and carboxyl group as macromolecular ligands and 1,10‐phenanthroline as co‐ligands. The fluorescence properties of the rare earth complexes and the influence of the contents of azobenzene chromophores on the fluorescent intensity are investigated by means of fluorescence excitation and emission spectroscopy. By exposing the films of the rare earth complexes to an interference pattern laser beam, SRGs can be formed on the films. Under the excitation, fluorescent patterns of the SRGs can be observed by the measurement of fluorescence microscopy. © 2015 Wiley Periodicals, Inc. J. Polym. Sci. Part A: Polym. Chem. 2015 , 53, 936–943     

Carbohydrate-appended curdlans as a new family of glycoclusters with binding properties both for a polynucleotide and lectins

Beta-1,3-glucans having carbohydrate-appendages (alpha-D-mannoside, N-acetyl-beta-D-glucosaminide and beta-lactoside) at the C6-position of every repeating unit can be readily prepared from curdlan (a linear beta-1,3-glucan) through regioselective bromination/azidation to afford 6-azido-6-deoxycurdlan followed by chemo-selective Cu(i)-catalyzed [3 + 2]-cycloaddition with various carbohydrate modules having a terminal alkyne. The resultant carbohydrate-appended curdlans can interact with polycytosine to form stable macromolecular complexes consistent with two polysaccharide strands and one polycytosine strand. Furthermore, these macromolecular complexes show strong and specific affinity toward carbohydrate-binding proteins (lectins). Therefore, one can utilize these carbohydrate-appended curdlans as a new family of glycoclusters.     

Preparation and photochemistry of macromolecular bound ruthenium(II) complexes in aqueous solutions

Ruthenium(II) polypyridyl complexes with macromolecular ligands poly(methylolacrylamide-co-vinylpyridine) and poly (acrylamide-co-vinylpyridine) have been synthesized. The macromolecular ruthenium (II) complexes which are soluble in water have been characterized and their absorption and emission properties have been studied in aqueous solution. Photolysis of the complex in aqueous solution leads to photoaquation reactions with release of coordinated pyridines of the polymer. In the case of monomeric complex, cis-[Ru(bpy)₂(py)₂]Cl₂, photolysis in water in presence of Cl^? ions produces only the substitution of the pyridine by water whereas in the polymeric complexes, [Ru(bpy)₂(MAAM-co-VP)₂]Cl₂ photolysis in the presence of chloride produces [Ru(bpy)₂(MAAM-co-VP)Cl]Cl and [Ru(bpy)₂(AM-co-VP)Cl]Cl, respectively. Quantum yields for the photosubstitution reactions have been determined and mechanistic details are outlined.     

Beta-1,3-glucan (schizophyllan) can act as a one-dimensional host for creation of novel poly(aniline) nanofiber structures

We here demonstrate the creation of novel poly(aniline) (PANI) nanofiber structures by a polymer wrapping method using schizophyllan (SPG). Mannose-modified SPG can also wrap PANIs to give nanofibers having a lectin affinity. This interaction is applicable to designing novel PANI/protein composites. The results establish that SPG can act as a novel "host" to assemble PANIs into one-dimensional superstructures. [reaction: see text]     

原位冷冻电子断层扫描的发展及在生物研究方面的应用

对生物大分子复合物的研究和结构分析对于全面了解其功能和生物学意义至关重要. 冷冻电子显微镜在提供生物大分子结构及大分子分布等方面起到重要的作用. 近年来, 冷冻电子显微镜的硬件和软件的发展进一步提高了冷冻电子显微镜的有效性, 使其对各种生物结构、 蛋白质结构的解析更加准确快捷. 但是, 对于生物系统来说, 蛋白质和大分子复合物等均处于复杂的生理环境中, 因此原位检测生物分子的三维结构对于生物体系和结构生物学具有重要意义. 冷冻电子断层扫描作为一种功能强大的技术, 可以无需标记直接通过冷冻样品的固有衬度识别生物大分子的结构, 并且可在原位生理环境中对生物分子进行纳米级分辨率的三维成像. 本文综述了与冷冻电子断层扫描相关的样品制备和数据处理技术, 并总结了冷冻电子断层扫描技术在分离的大分子复合物和整个细胞或组织中的生物学应用.     

Specific features of nonstoichiometric interpolymer complexes of poly(acrylic acid) and poly(ethylene glycol) as protectors of copper nanoparticles in aqueous sols

Advantages of interpolymer complexes for use as amphiphilic protectors of nanoparticles during the formation and stabilization of sols are considered. The effects of the ratio of poly(acrylic acid) and poly(ethylene glycol) and the molecular mass of poly(ethylene glycol) on the mean size and size distribution of copper nanoparticles in sols formed via the reduction of divalent copper ions in mixed aqueous solutions of these polymers are investigated. It is shown that sols of metal nanoparticles with small sizes and narrow size distributions are formed even when poly(ethylene glycols) with chain lengths below the “critical” chain length and a small PEG-to-PAA base-molar ratio are used. This is evidence for efficient protection of the formed copper nanoparticles by the interpolymer complex PEG-PAA under conditions of its instability and for self-organization of oligomeric PEG chains in complex macromolecular shields of nanoparticles.     

Macromolecular helicity inversion of poly(phenylacetylene) derivatives induced by various external stimuli

Unique macromolecular helicity inversion of stereoregular, optically active poly(phenylacetylene) derivatives induced by external achiral and chiral stimuli is briefly reviewed. Stereoregular, cis-transoidal poly(phenylacetylene)s bearing an optically active substituent, such as (1R,2S)-norephedrine (poly- 1 ) and β-cyclodextrin residues (poly- 2 ), show an induced circular dichroism (ICD) in the UV-visible region of the polymer backbone in solution due to a predominantly one-handed helical conformation of the polymers. However, poly- 1 undergoes a helix-helix transition upon complexation with chiral acids having an R configuration, and the complexes exhibit a dramatic change in the ICD of poly- 1 . Poly- 2 also shows the inversion of macromolecular helicity responding to molecular and chiral recognition events that occurred at the remote cyclodextrin residues from the polymer backbone; the helicity inversion is accompanied by a visible color change. A similar helix-helix transition of poly((R)- or (S)-(4-((1-(1-naphthyl)ethyl)carbamoyl)phenyl)acetylene) is also briefly described.     

Thermo‐Responsive Complexes of c‐Myc Antisense Oligonucleotide with Block Copolymer of Poly(OEGMA) and Quaternized Poly(4‐Vinylpyridine)

Solution behavior of thermo‐responsive polymers and their complexes with biological macromolecules may be affected by environmental conditions, such as the concentration of macromolecular components, pH, ion concentration, etc. Therefore, a thermo‐responsive polymer and its complexes should be characterized in detail to observe their responses against possible environments under physiological conditions before biological applications. To briefly indicate this important issue, thermo‐responsive block copolymer of quaternized poly(4‐vinylpyridine) and poly(oligoethyleneglycol methyl ether methacrylate) as a potential nonviral vector has been synthesized. Polyelectrolyte complexes of this copolymer with the antisense oligonucleotide of c‐Myc oncogene are also thermo‐responsive but, have lower LCST (lower critical solution temperature) values compared to individual copolymer. LCST values of complexes decrease with molar ratio of macromolecular components and presence of salt. Dilution of solutions also affects solution behavior of complexes and causes a significant decrease in size and an increase in LCST, which indicates possible effects of severe dilutions in the blood stream.

     

β-1,3-Glucan (Schyzophyllan) Can Act as a One-Dimensional Host for Creating Chirally Twisted Poly(p-phenylene Ethynylene)

It has been demonstrated that a chiral, insulated poly(p-phenylene ethynylene) (PPE) nano-wire can be created by a polymer wrapping method utilizing natural β-1,3-glucan polysaccharide schizophyllan (SPG). Spectroscopic and microscopic measurements have revealed that PPE adopts a rigid conformation and exists as one piece in the helical hollow constructed by two SPG chains. Moreover, the inherent helical structure of SPG can induce the chiral twisting of the insulated PPE backbone. It is believed that the present system is really applicable for designing novel chiral sensors based on PPE.     

Proteomic dissection of biological pathways/processes through profiling protein-protein interaction networks

Cellular functions, either under the normal or pathological conditions or under different stresses, are the results of the coordinated action of multiple proteins interacting in macromolecular complexes or assemblies. The precise determination of the specific composition of protein complexes, especially using scalable and high-throughput methods, represents a systematic approach toward revealing particular cellular biological functions. In this regard, the direct profiling protein-protein interactions (PPIs...     

Liposome delivered and polymeric metal complexes as potential sensitizers for the photodynamic therapy of cancer

Different possibilities of macromolecular metal complexes as photosensitizers (PS) for their potential use in the photodynamic therapy of cancer are described. The prepared metal porphyrazin derivatives (metals: Zn(II), Si(IV)(X)₂) exhibit long wavelength absorption and high singlet oxygen quantum yields under irradiation. One possibility is the incorporation of the PSs in liposomal vesicles giving hydrophobic conjugates with low densitiy proteins in the serum after injection. Good tumor accumulation and photodynamic activities are observed. Increased tumor uptake is also known for Pcs covalently connected via the ligand to poly(ethylene glycol monomethyl ether). New compounds contain the hydrophilic polymer at axial substituents of Si(X)₂Pc and Si(X)₂Nc. Some newly synthesized compounds with only one functional group exhibit the possibility of coupling to macromolecules like e.g. monoclonal antibodies.     

Highly efficient non-biofouling coating of zwitterionic polymers: poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide)

This work describes the formation of highly efficient non-biofouling polymeric thin films of poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide), (poly(MPDSAH)). The poly(MPDSAH) films were generated from the self-assembled monolayers terminating in an initiator of atom transfer radical polymerization (ATRP) by the surface-initiated ATRP of MPDSAH. The poly(MPDSAH) films on a gold surface were characterized by ellipsometry, FT-IR spectroscopy, contact angle goniometery, and X-ray photoelectron spectroscopy. The copper complexes and unpolymerized monomers trapped inside the polymer brushes were completely washed out by soaking the poly(MPDSAH)-coated substrate in water at 40 degrees C for 4 days. The amount of proteins nonspecifically adsorbed onto the poly(MPDSAH) films was evaluated by surface plasmon resonance spectroscopy: the adsorption of proteins was <0.6 ng/cm(2) on the surfaces for all the model proteins. The ability of the poly(MPDSAH) films to resist the nonspecific adsorption of proteins was comparable to that of the best known systems.