概括
新的恒星聚合物可以在患病的组织中选择性地检测过氧化 (H2O2). 这些聚合物的分解,由H2O2触发,可以使用磁共振成像 (MRI) 进行可视化,提供一种新的诊断工具.
科学领域:
- 聚合物化学 聚合物化学
- 化学生物学 化学生物学
- 生物医学诊断 生物医学诊断
背景情况:
- 活性氧物种 (ROS) 度升高,特别是过氧化 (H2O2),是患病组织微环境的特征.
- 选择性检测ROS对于开发新的诊断方法和化学生物学工具至关重要.
研究的目的:
- 合成和表征用于选择性H2O2检测的新型核心交联刷臂星聚合物 (BASPs).
- 研究H2O2诱导的拆解机制及其在诊断成像中的应用.
主要方法:
- 用聚乙烯糖醇 (PEG) 或PEG-分支-螺旋环氧化 (chex) 合成乙烯-bis-norbornene核心交叉链接的BASP.
- 使用尺寸排除色谱 (SEC) 和动态光散射 (DLS) 进行表征.
- 评价H2O2选择性和MRI检测聚合物拆解.
主要成果:
- 成功合成了具有狭窄摩尔质量分布和平均水力动力直径为23 ± 2纳米的BASP.
- 核心外结构使选择性拆卸能够在对H2O2的反应中超过其他ROS,如ONOO-和OCl-.
- 检查含有BASP的拆卸诱导了MRI的横向磁性放松率的可检测变化.
结论:
- 响应H2O2的BASP在检测H2O2时具有很高的选择性.
- 检查-BASP为H2O2传感提供了一个有前途的平台,并且可以使用MRI进行可视化.
- 这些聚合物代表了与H2O2相关的疾病的宝贵新诊断工具.
相关概念视频
Cationic Chain-Growth Polymerization: Mechanism
2.4K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.4K
Hydroboration-Oxidation of Alkenes
8.4K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
8.4K
Regioselectivity of Electrophilic Additions-Peroxide Effect
8.7K
In the presence of organic peroxides, the addition of hydrogen bromide to an alkene yields the isomer that is not predicted by Markovnikov’s rule. For example, the addition of hydrogen bromide to 2-methylpropene in the presence of peroxides gives 1-bromo-2-methylpropane. This addition reaction proceeds via a free radical mechanism, which reverses the regioselectivity. The free radical reaction mechanism involves three stages: initiation, propagation, and termination.
8.7K
Hydrolysis
105.7K
Overview
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...
105.7K
Radical Formation: Homolysis
3.6K
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
3.6K
Radical Anti-Markovnikov Addition to Alkenes: Mechanism
3.8K
The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...
3.8K


