The preparation of perfectly alternating and regioslective copolymers derived from the copolymerization of carbonyl sulfide (COS) and epoxides by metal‐free Lewis pair catalysts composed of a Lewis base (amidine, gua...
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The preparation of perfectly alternating and regioslective copolymers derived from the copolymerization of carbonyl sulfide (COS) and epoxides by metal‐free Lewis pair catalysts composed of a Lewis base (amidine, guanidine, or quaternary onium salts) and a Lewis acid (triethyl borane) is described. Colorless and highly transparent copolymers of poly(monothiocarbonate) were successfully obtained with over 99 % tail‐to‐head content and high molecular weight (up to 92.5 kg mol −1 ). In most instances, oxygen–sulfur exchange reactions (O/S ERs), which would generate random thiocarbonate and carbonate units, were effectively suppressed. The turnover frequencies (TOF) of these Lewis pair catalyzed processes were as high as 119 h −1 at ambient temperature.
Magnetic resonance imaging (MRI) is a promising technique widely used in clinical diagnose. Poly(α-amino acid)s are excellent carriers for MRI due to their excellent biocompatibility. PDOPA-b-PSar copolymers (defined...
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Magnetic resonance imaging (MRI) is a promising technique widely used in clinical diagnose. Poly(α-amino acid)s are excellent carriers for MRI due to their excellent biocompatibility. PDOPA-b-PSar copolymers (defined as “DoS”) are synthesized by sequential polymerizations of 3,4-dihydroxy-L-phenylalanine N-thiocarboxyanhydride (DOPA-NTA) and sarcosine N-thiocarboxyanhydride (Sar-NTA) initiated by neopentylamine in tetramethylene sulfone. Mn2+@DoS micelles have been prepared as T1-weighted MRI contrast agents according to efficient coordination between catechol units and Mn2+cation. High longitudinal relaxivity (27.7 mM−1·s−1) of Mn2+@PDOPA12-b-PSar72was observed, and the aqueous micelle exhibits effective MRI contrast enhancementin vivoof nude mice. Mn2+@DoS shows potential clinical application in diagnostic radiology as a novel MRI contrast agent. Gd3+@DoS micelles are also investigated presenting a longitudinal relaxivity of 16.4 mM−1·s−1. Unfortunately, the Gd3+loading percentage is quite low as 19%.Preparation of Mn2+@PolyDOPA-b-polysarcosine micelle as MRI contrast agent with high longitudinal relaxivityAll authorsQingdaYan,XueDong,RongzeXie,XiufangXu,XiaoyanWang,KeZhang,JingyaXia,JunLing,FeiZhou&JihongSunhttps://***/10.1080/10601325.2020.1840918Published online:02 November 2020
Adavosertib(ADA)is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer(GBC).However,drug resistance due to DNA damage response compensation pathways and high toxicity limits furt...
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Adavosertib(ADA)is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer(GBC).However,drug resistance due to DNA damage response compensation pathways and high toxicity limits further ***,estrone-targeted ADA-encapsulated metal–organic frameworks(ADA@MOF-EPL)for GBC synthetic lethal treatment by inducing conditional factors are *** high expression of estrogen receptors in GBC enables ADA@MOF-EPL to quickly enter and accumulate near the cell nucleus through estrone-mediated endocytosis and release ADA to inhibit WEE1 upon entering the acidic tumor *** irradiation induces ADA@MOF-EPL to generate reactive oxygen species(ROS),which leads to a further increase in DNA damage,resulting in a higher sensitivity of p53-mutated cancer cells to WEE1 inhibitor and promoting cell death via conditional synthetic *** conditional factor induced by ADA@MOF-EPL further enhances the antitumor efficacy while significantly reducing systemic ***,ADA@MOF-EPL demonstrates similar antitumor abilities in other p53-mutated solid tumors,revealing its potential as a broad-spectrum antitumor drug.
Organic pollutants pose a significant challenge due to their toxicity and potential carcinogenicity, posing a severe threat to the environment and human health. Heterogeneous photocatalysts offer promising advantages ...
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The reduced oxygen concentration is a distinctive feature of osteoarthritic (OA) cartilage, whereas the mechanical friction also contributes to the inflammatory hypoxia microenvironment of OA. Herein, novel hypoxia-re...
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