Sequentially Programmable and Cellularly Selective Assembly of Fluorescent Polymerized Vesicles for Monitoring Cell Apoptosis

Abstract

The introduction of controlled self‐assembly into living organisms opens up desired biomedical applications in wide areas including bioimaging/assays, drug delivery, and tissue engineering. Besides the enzyme‐activated examples reported before, controlled self‐assembly under integrated stimuli, especially in the form of sequential input, is unprecedented and ultimately challenging. This study reports a programmable self‐assembling strategy in living cells under sequentially integrated control of both endogenous and exogenous stimuli. Fluorescent polymerized vesicles are constructed by using cholinesterase conversion followed by photopolymerization and thermochromism. Furthermore, as a proof‐of‐principle application, the cell apoptosis involved in the overexpression of cholinesterase in virtue of the generated fluorescence is monitored, showing potential in screening apoptosis‐inducing drugs. The approach exhibits multiple advantages for bioimaging in living cells, including specificity to cholinesterase, red emission, wash free, high signal‐to‐noise ratio.

Real‐Time Cellular Cytochrome C Monitoring through an Optical Microfiber: Enabled by a Silver‐Decorated Graphene Nanointerface

“…In clinical disease diagnosis, once pathological conditions are triggered by cardiac failure, DNA damage, cytoskeleton disruption, or invasion from outside cells, the cyt c in mitochondria can be released into the bloodstream via permeabilization of injured mitochondria . Thus, cyt c monitoring not only serves as an apoptosis biomarker, providing valuable information about the nature and extent of this process, but also is of great importance to understand certain diseases at the cellular level . The techniques available currently in laboratories to measure cyt c release include flow cytometry, Western blot, enzyme‐linked immunosorbent assay, high‐performance liquid chromatography, and spectrophotometry .…”

Photopolymerization, Thermochromism and Application of Diacetylene Vesicle

“…电化学、动力学、胶体与表面化学四个部分。其中热力学部分包含"燃烧热的测定""液体饱和蒸 汽压的测定""二组分体系的气-液平衡相图""分解反应平衡常数"四个实验；电化学部分包含 "电解质溶液电导的测定""电动势的测定""氢阴极析出极化曲线的测定""方波脉冲电流镀 锌"四个实验；动力学部分包括"过氧化氢分解反应""蔗糖酸催化转化反应""丙酮碘化反 应""溶液中的离子反应"四个实验；胶体与表面化学部份包括"气体-溶液界面上的吸附""黏度 法测定高聚物的相对分子质量""电泳""水溶性表面活性剂的临界胶束浓度测定"四个实验 [1] 。 这些实验覆盖了众多重要知识点。不过美中不足的是，这些实验中涉及到的知识点较为单一，缺乏 相互关联性。因此有必要设计开发一个新的综合型实验项目，能够将不同章节的知识点融会贯通， 并且和学科最新科研成果相结合，作为以科研反哺教学的典型实例。 胆碱酯酶是细胞凋亡的标记物之一，其检测与成像一直是学术界的难题。郭东升教授课题组通 过将联二炔(DA)与胆碱共价结合得到胆碱酯酶探针(DC)，其只有在程序性地被胆碱酯酶切除胆碱、 紫外光照聚合和体温环境下变色后才产生荧光信号，可以有效进行细胞内胆碱酯酶成像和监测凋亡 细胞 [2] 。该研究工作中关于联二炔的实验步骤简单易行，联二炔变色效果十分明显，便于本科生操 作，也容易引起学生的兴趣。更重要的是，其涉及到物理化学中的胶体、光化学、热力学、动力学 等多个章节的内容，能使学生更好的把握章节之间知识点的关联性，因而十分适合将其应用到本科 生实验课程中。我们提取该工作中部分内容，适当修改与补充，设计出了一个创新性实验，为解决 物理化学实验中知识贯通性和科学前沿性的问题提供了一个典型范例。 [4][5][6] 。实验过程中，将 DA 溶于氯仿后，吹干溶剂使之在器皿 表面成膜。之后，向体系中加入 2-[4-(羟乙基)-1-哌嗪基]乙磺酸 (HEPES)缓冲溶液(pH = 7.4， 10 mmol•L −1 )并加热超声，DA 自组装形成囊泡 [7][8][9] [6] Copyright 2019 Bentham Science Publishers.…”

Interface Sensitized Optical Microfiber Biosensors

“…Its release from mitochondria is an essential signal of the initial progression of programmed cell death [46]. Therefore, in clinical disease diagnosis, the monitoring of cytochrome c, which serves as an apoptosis biomarker, is of great importance to understand certain diseases at the cellular level [47], [48]. However, the lowest LOD of the techniques available currently in laboratories to measure cytochrome c is only 10 −12 M [46], which is insufficient to trace the initiation of apoptosis in situ (out of cells).…”