2,3 : 6,7-Dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-diol was synthesized and resolved via (−)-menthoxyacetate. Several kinds of optically active derivatives with the same absolute configuration were prepared from the (−)-diol and their chiroptical properties were recorded. The absolute configuration of this series of compounds was determined to be 1R, 5R by a chemical correlation with (R)-(−)-3-phenylbutanoic acid via (−)-1,3-diphenylglutaric acid and (−)-2,4-diphenylpentane.
SYNOPSISAn affinity membrane was prepared from a porous cellulose membrane, and adsorption and recovery of serum proteins were investigated from the viewpoint that affinity membranes are efficacious against separation and purification of biomaterials. Into the cellulose membrane, iminodiacetate (IDA) group that acts as a ligand to metal ions was introduced (Cell-IDA membrane), and then Cu2+ ion was immobilized (Cell-IDA-Cu membrane). Bovine serum albumin (BSA) and y-globulin (BrG), which are the major proteins in blood, were adopted as model proteins to be separated. The Cell-IDA-Cu membrane had large adsorption capacity for these proteins despite the low degree of modification. The amounts of proteins adsorbed on the Cell-IDA-Cu membrane increased with increasing pH, and ByG was adsorbed more than BSA. High protein recoveries from the Cell-IDA-Cu membrane were obtained. The separation of these proteins was also conducted under the optimum conditions of adsorption and recovery, and ByG was concentrated more than BSA although the initial concentration of ByG was lower than that of BSA. 0 1996 John Wiley & Sons, Inc. I NTRO DUCT10 NA number of studies on the separation and purification of biomaterials, such as proteins and enzymes, have been developed with a growing demand for them in many fields ranging from food to drug. Affinity column chromatography is one of the most powerful techniques to separate and purify them, and different kinds of packings are available. Immobilized metal affinity chromatography (IMAC) was also evolved for the isolation of biomaterials.' There have been extensive discussions on the properties as well as preparation of IMAC.2-6 In IMAC, transition metal ions immobilized on polymer matrices are coordinated by proteins through their electron donor groups, such as histidine, cysteine, and tryptophanIn addition to the development of novel adsorbents for affinity columns, improvements in adsorbent geometry have been undertaken to process a large quantity of proteins rapidly. In order to obtain the higher performance on the processing ability of
Oxaborole-based polymers are stimuli-responsive materials that can reversibly interact with diols at pH values higher than their pK a. The strong binding of the oxaborole with cis-hydroxyl groups allow rapid cross-linking of the polymer chains. In this study, we exploited this phenomenon to develop a novel delivery system for the complexation, protection, and delivery of epidermal growth factor receptors (EGFR) siRNA (small interfering RNA). Galactose and oxaborole polymers were first synthesized by the reversible addition–fragmentation chain transfer (RAFT) process, and they were found to show a robust interaction with each other via the oxaborole-diol effect, which allowed the formation of stable polyplexes with siRNA. Although complexes were successfully formed between the neutral galactose and oxaborole-based polymers, these complexes were insufficient in the protection of the siRNA. Therefore, cationic glycopolymers and oxaborole polymers were investigated showing superior complexation with siRNA and exhibiting effective gene silencing in HeLa (cervical) cancer cells, while showing low toxicity. Gene silencing of up to 60% was achieved with these new complexes in the presence and absence of serum. The excellent stability of the complexes under physiological conditions and the observed low cytotoxicity 48 h post-transfection demonstrated the high potential of this new system for gene silencing therapy application in clinics.
Recently, we have succeeded in identifying the structure of the adsorption layer of ethanol on a silica surface in cyclohexane to be a hydrogen-bonded linear aggregate (polymer), which we call a surface molecular macrocluster. In this work, we studied the effect of the miscibility of liquids on the formation of the surface molecular macroclusters for confirming that this is a surface induced phenomenon. We investigated the interaction and the structure of methanol adsorbed on a silica surface in methanol-cyclohexane binary liquids by a combination of colloidal probe atomic force microscopy, adsorption excess isotherm measurement, and FTIR spectroscopy using the attenuated total reflection (ATR) mode, and compared the results with those of the ethanol-cyclohexane and 1-propanol-cyclohexane binary liquids. The former system is immiscible at methanol concentrations of ca. 8-90 mol %, and the latter two are miscible at any composition. At 0.03 mol % methanol, which is far from the critical concentration for the phase separation, the contact of the methanol macrocluster layers formed on the silica surface brought about the attraction from a distance of 42 +/- 5 nm which was similar to that observed in ethanol-cyclohexane. At a methanol concentration of 9.0 mol %, above bulk phase separation, completely different force profiles were observed. These results demonstrated that the molecular macrocluster formation was different from the wetting induced by the bulk.
Apoptotic cell death serves important roles in homeostasis by eliminating dangerous, damaged, or unnecessary cells without causing an inflammatory response by externalizing phosphatidylserine to the outer leaflet in the phospholipid bilayer. In this study, we newly designed apoptotic cell membrane-inspired monomer and polymer which have the phosphoryl serine group as the antiinflammatory functional moiety and demonstrate here for the first time that administration of an apoptotic cell membrane-inspired phosphorylserine polymer can protect murine macrophages (RAW 264.7) from lipopolysaccharideinduced inflammation. Interestingly, statistical copolymers with phosphorylcholine monomer that mimicked more precisely the apoptotic cell membrane result in more effective suppression of macrophage activation. This study provides new insights into the rational design of effective polymeric materials for anti-inflammatory therapies.
Messenger RNA (mRNA) therapeutics have recently demonstrated high clinical potential with the accelerated approval of SARS-CoV-2 vaccines. To fulfill the promise of unprecedented mRNA-based treatments, the development of safe and efficient carriers is still necessary to achieve effective delivery of mRNA. Herein, we prepared mRNA-loaded nanocarriers for enhanced in vivo delivery using biocompatible block copolymers having functional amino acid moieties for tunable interaction with mRNA. The block copolymers were based on flexible poly(ethylene glycol)-poly(glycerol) (PEG-PG) modified with glycine (Gly), leucine (Leu) or tyrosine (Tyr) via ester bonds to generate block catiomers. Moreover, the amino acids can be gradually detached from the block copolymers after ester bond hydrolyzation, avoiding cytotoxic effects. When mixed with mRNA, the block catiomers formed narrowly distributed polymeric micelles with high stability and enhanced delivery efficiency. Particularly, the micelles based on tyrosine-modified PEG-PG (PEG-PGTyr), which formed a polyion complex (PIC) and π–π stacking with mRNA, displayed excellent stability against polyanions and promoted mRNA integrity in serum. PEG-PGTyr-based micelles also increased the cellular uptake and the endosomal escape, promoting high protein expression both in vitro and in vivo . Furthermore, the PEG-PGTyr-based micelles significantly extended the half-life of the loaded mRNA after intravenous injection. Our results highlight the potential of PEG-PGTyr-based micelles as safe and effective carriers for mRNA, expediting the rational design of polymeric materials for enhanced mRNA delivery.
Indoleamine 2,3-dioxygenase (IDO) is an immunomodulating enzyme that is overexpressed in many cancers with poor prognosis. IDO suppresses T cell immunity by catabolizing tryptophan into kynurenine (KYN), which induces apoptosis in T effector cells and enhances T regulatory cells, providing a powerful immunosuppressive mechanism in tumors. Thus, major efforts for developing IDO inhibitors have been undertaken. Among them, 1-Methyl-l-Tryptophan (MLT) and 1-Methyl-d-Tryptophan (MDT) effectively inhibit IDO in preclinical tumor models and the latter is under clinical evaluation. However, both MLT and MDT present poor pharmacokinetics, with the maximum serum concentration being below their 50% inhibitory concentration value. Herein, we have developed polymeric IDO inhibitors based on MLT, which can release active MLT after enzymatic degradation, toward establishing superior antitumor immunotherapies. These polymers were prepared by ring opening polymerization of an N-phenyl carbamate (NPC) derivative of MLT that was synthesized by carbamylation with diphenyl carbonate. By using ω-amino-poly(ethylene glycol) (PEG-NH2) as the macroinitiator, we prepared amphiphilic PEG-poly(MLT) block copolymers, which self-assembled into polymeric micelles in aqueous conditions. The PEG-poly(MLT) block copolymers could be readily degraded by chymotrypsin and the micelles were able to reduce the levels of KYN in activated macrophages. These results provide a strong rationale for pursuing MLT-based polymeric micelles as tumor-targeted prodrug systems.
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