Recent Chemical Approaches for Site-Specific Conjugation of Native Antibodies: Technologies toward Next-Generation Antibody–Drug Conjugates

Antibody–drug conjugates (ADCs), which consist of three components, antibody, linker, and payload, can function as “magic bullets”. These conjugates offer the ability to target drug delivery to specific cells, based on cell-specific recognition and the binding of an antigen by a monoclonal antibody (mAb). In particular, by delivering a cytotoxic payload to cancer cells, ADCs are expected to provide a breakthrough in oncology treatments by providing a way to increase efficacy and decrease toxicity, in comparison with traditional chemotherapeutic treatments. The development of ADC therapeutics has dramatically progressed in the past decade and two ADCs have been approved and used as anticancer drugs in the clinic. However, several critical issues regarding the performance of ADCs are still being discussed and investigated. Indeed, in the past few years, several groups have reported that, changing the number and position of the drug payloads in the ADCs, affects the pharmacokinetics, drug release rates, and biological activity. The use of conventional heterogeneous conjugation methods for ADC preparation results in the drug/antibody ratio and connecting position of the payload having stochastic distributions. Therefore, it is important to investigate how these potential problems can be circumvented through site-specific conjugation. Herein, various site-specific chemical conjugation strategies with native mAbs that are currently used for the production of ADCs, including residue-selective labeling for generating ADCs, disulfide rebridging, and affinity-peptide-mediated site-specific chemical conjugation technologies, are reviewed and described.     

Catechol - an Oviposition Stimulant for Cigarette Beetle in Roasted Coffee Beans

The cigarette beetle, Lasioderma serricorne, is a serious global pest that preys on stored food products. Larvae of the beetle cannot grow on roasted coffee beans or dried black or green tea leaves, although they oviposit on such products. We investigated oviposition by the beetles on MeOH extracts of the above products. The number of eggs laid increased with an increase in dose of each extract, indicating that chemical factors stimulate oviposition by the beetles. This was especially true for \ coffee bean extracts, which elicited high numbers of eggs even at a low dose (0.1 g bean equivalent/ml) compared to other extracts. Coffee beans were extracted in hexane, chloroform, 1-butanol, MeOH, and 20 % MeOH in water. The number of eggs laid was higher on filter papers treated with chloroform, 1-butanol, MeOH, and 20 % MeOH in water extracts than on control (solvent alone) papers. The chloroform extract was fractionated by silica-gel column chromatography. Nine compounds were identified by gas chromatography/mass spectrometry from an active fraction. Of these compounds, only a significant ovipositional response to catechol was observed.     

Chimeric Mice with Humanized Livers: A Unique Tool for in Vivo and in Vitro Enzyme Induction Studies

We performed in vivo and in vitro studies to determine the induction of human cytochrome P450 (CYP) using chimeric mice with humanized liver (PXB-mice^®) and human hepatocytes isolated from the PXB-mice (PXB-cells), which were derived from the same donor. For the in vivo study, PXB-mice were injected with 3-methylcholanthrene (3-MC, 2 or 20 mg/kg) or rifampicin (0.1 or 10 mg/kg) for four days. For the in vitro study, PXB-cells were incubated with 3-MC (10, 50, or 250 ng/mL) or with rifampicin (5 or 25 μg/mL). The CYP1A1 and 1A2, and CYP3A4 mRNA expression levels increased significantly in the PXB-mouse livers with 20 mg/kg of 3-MC (C_max, 12.2 ng/mL), and 10 mg/kg rifampicin (C_max, 6.9 μg/mL), respectively. The CYP1A1 mRNA expression level increased significantly in PXB-cells with 250 ng/mL of 3-MC, indicating lower sensitivity than in vivo. The CYP1A2 and CYP3A4 mRNA expression levels increased significantly with 50 ng/mL of 3-MC, and 5 μg/mL of rifampicin, respectively, which indicated that the sensitivities were similar between in vivo and in vitro studies. In conclusion, PXB-mice and PXB-cells provide a robust model as an intermediate between in vivo and in vitro human metabolic enzyme induction studies.     

氧化钙对氯氧镁水泥低温凝结性能的影响

为了深入研究氯氧镁水泥低温凝结机理,进而改善和提高氯氧镁水泥在低温时的快硬性能,把氧化钙加入到氯氧镁水泥料浆中,通过搅拌、成型、恒温恒湿箱养护后测定其凝结时间及早期强度。结果表明：氧化钙加入后放出热量,引发氯氧镁水泥水化起始期反应的进行,有效缩短氯氧镁水泥的凝结时间。当氧化钙掺量为氧化镁质量的4%时,氧化镁活性为62.24%和72.01%时初凝时间分别由593 min缩短到146 min、由570 min缩短到126 min,终凝时间分别由673 min缩短到374 min、由641 min缩短到260 min,同时都提高了氯氧镁水泥的低温早期强度。     

Critical update on 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymer science

2‐Methacryloyloxyethyl phosphorylcholine (MPC) is a custom methacrylate with a zwitterionic phosphorylcholine moiety on the side chain. In the past 25 years, MPC has been used as a building block for a wide range of polymeric biomaterials because of its excellent resistance to nonspecific protein adsorption, cell adhesion, and blood coagulation. Recently, MPC polymers with specific features have been used in bioengineering and nanomedicine. This review focuses on three topics that highlight the latest findings on MPC polymers, that is, specific recognition of C‐reactive protein (CRP), cell‐membrane‐penetration abilities, and lubrication properties. These developments will extend the applications of this biomimetic material from bioinert polymers to biosensing, CRP inhibitors, prodrug carriers, subcellular bioimaging, cell manipulation, and joint replacement. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41766.     

Combination Treatment of OSI-906 with Aurora B Inhibitor Reduces Cell Viability via Cyclin B1 Degradation-Induced Mitotic Slippage

Insulin-like growth factor 1 receptor (IGF1R), a receptor-type tyrosine kinase, transduces signals related to cell proliferation, survival, and differentiation. We recently reported that OSI-906, an IGF1R inhibitor, in combination with the Aurora B inhibitor ZM447439 suppresses cell proliferation. However, the mechanism underlying this suppressive effect is yet to be elucidated. In this study, we examined the effects of combination treatment with OSI-906 and ZM447439 on cell division, so as to understand how cell proliferation was suppressed. Morphological analysis showed that the combination treatment generated enlarged cells with aberrant nuclei, whereas neither OSI-906 nor ZM447439 treatment alone caused this morphological change. Flow cytometry analysis indicated that over-replicated cells were generated by the combination treatment, but not by the lone treatment with either inhibitors. Time-lapse imaging showed mitotic slippage following a severe delay in chromosome alignment and cytokinesis failure with furrow regression. Furthermore, in S-trityl-l-cysteine–treated cells, cyclin B1 was precociously degraded. These results suggest that the combination treatment caused severe defect in the chromosome alignment and spindle assembly checkpoint, which resulted in the generation of over-replicated cells. The generation of over-replicated cells with massive aneuploidy may be the cause of reduction of cell viability and cell death. This study provides new possibilities of cancer chemotherapy.     

以白云石为原料制备球状碳酸镁的研究

本文探讨了以白云石为原料合成球状碳酸镁的原理、方法及影响因素。研究了煅烧温度、碳化温度、灰乳浓度、二氧化碳浓度、添加剂、热解温度等对产品的影响。通过试验 ,获得了制备球状碳酸镁的适宜条件。     

Structural analysis of oriented poly(ε‐caprolactone) including CaCO3 particles with 13C solid‐state NMR

The results of a study of the relation between the oriented structure and drawn Poly(ε‐caprolactone) specimens including CaCO₃ particles and their dynamic mechanical properties are presented. The loss elasticity, E″, showed almost the same curve for both undrawn sheets and drawn sheets as a function of CaCO₃ content. On the other hand, the storage modulus, E′, of drawn sheets increased nonlinearly with increasing CaCO₃ content, and their curve showed lower E′ values than those of undrawn sheets. By simulation of ¹³C CP NMR spectra of drawn PCL/CaCO₃ sheets, both oriented and unoriented components were observed. The distribution parameter, p, of drawn PCL/CaCO₃ sheets was 13°, which was larger than those (8°) of drawn PCL. Further, the fraction of the unoriented component increased with increasing CaCO₃ content. Thus, adding CaCO₃ particles into the PCL, the arrangement of the oriented component was disturbed and decreased. In addition, from the line shape analyses of ¹³C CP MAS NMR spectra, four peaks were obtained in not only undrawn sheets but also in drawn sheets of both PCL and PCL/CaCO₃ compounds. Besides, structural change occurred at only drawn PCL/CaCO₃ sheets. Therefore, the change in dynamic mechanical properties observed only for drawn PCL/CaCO₃ sheets were strongly dependent on the orientational structure, which was formed under shear stress of the stretching drawn process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2376–2382, 2001     

CD147 Is Essential for the Development of Psoriasis via the Induction of Th17 Cell Differentiation

Th17 cells play an important role in psoriasis. The differentiation of naïve CD4⁺ T cells into Th17 cells depends on glycolysis as the energy source. CD147/basigin, an integral transmembrane protein belonging to the immunoglobulin superfamily, regulates glycolysis in association with monocarboxylate transporters (MCTs)-1 and -4 in cancer cells and T cells. We examined whether CD147/basigin is involved in the pathogenesis of psoriasis in humans and psoriasis-model mice. The serum level of CD147 was increased in patients with psoriasis, and the expression of CD147 and MCT-1 was elevated in their dermal CD4⁺ RORγt⁺ T cells. In vitro, the potential of naïve CD4⁺ T cells to differentiate into Th17 cells was abrogated in CD147^−/− T cells. Imiquimod (IMQ)-induced psoriatic dermatitis was significantly milder in CD147^−/− mice and bone marrow chimeric mice lacking CD147 in the hematopoietic cells of myeloid lineage. These findings demonstrate that CD147 is essential for the development of psoriasis via the induction of Th17 cell differentiation.     

Production of MAG of CLA by esterification with dehydration at ordinary temperature using <Emphasis Type="Italic">Penicillium camembertii</Emphasis> lipase

Production of MAG with CLA using Penicillium camembertii mono- and diacylglycerol lipase (referred to as lipase) was attempted for the purpose of expanding the application of CLA. The commercial product of CLA (referred to as FFA-CLA) is a FFA mixture containing almost equal amounts of 9cis,11trans (9c,11t)-CLA and 10t,12c-CLA. Esterification of FFA-CLA with glycerol without dehydration achieved 84% esterification but produced almost equal amounts of MAG and DAG. Esterification with dehydration not only achieved a high degree of esterification but also suppressed the formation of DAG. When a mixture of FFA-CLA/glycerol (1∶2, mol/mol), 1% water, and 200 units/g-mixture of P. camembertii lipase was agitated at 30°C for 72 h with dehydration at 5 mm Hg, the degree of esterification reached 95% and the contents of MAG and DAG were 90 and 6 wt%, respectively. This reaction system may be applied to the industrial production of MAG with unstable CLA.