Characterizing doxorubicin‐induced apoptosis in HepG2 cells using an integrated microfluidic device

Abstract

Apoptosis has now established its importance in numerous areas of biology and is recently receiving great attention as an important topic related to the development of diseases. In this work, an integrated microfluidic device was developed to characterize doxorubicin-induced apoptosis in human hepatocellular carcinoma (HepG2) cells. A continuous concentration gradient of stimulator (doxorubicin) was generated in the upstream network and used to perfuse downstream cultured HepG2 cells. The appropriate fluorescent dyes were introduced into cells from the inlets connected to the cell culture chambers, allowing one to distinguish apoptotic cells from nonapoptotic or necrotic cells. The resultant fluorescence of cellular population was monitored and quantified with single-cell resolution to infer the apoptosis process being studied. The feasibility of studying apoptosis was demonstrated by measuring several apoptotic events, including morphological alterations, plasma membrane phosphatidylserine externalization, and mitochondrial membrane potential collapse. This microfluidic device, integrating the cell culture, stimulation, staining, and washing steps into a single device, can simultaneously generate a number of experimental conditions and investigate multiple parameters relating stimulation to apoptosis. It offers a unique platform to characterize various cellular responses in a high-throughput fashion, which is otherwise impossible with conventional methods.

An integrated microfluidic array system for evaluating toxicity and teratogenicity of drugs on embryonic zebrafish developmental dynamics

“…2͑c͒, it was found that the experimental data were correlated well with the theoretical prediction, 30 and the central parts of channels with more errors presumably ascribed to the hydraulic defocusing at the merged points. 42 By comparing with previous similar works, 37,42 the data obtained here matched them well.…”

“…This property contributed to the stable position of embryos under the flowing system, and enabled the microfluidic chip that applied in fish embryo-associated assay to be used repeatedly comparable to the microdevice for cell-based assay. 37 In the tests, we placed the microfluidic device at an angle of about 20°to horizontal level to facilitate the withdrawal of waste without additional use of tubes, and the open culture chamber can still maintain the normoxia development for embryos that was particularly important for larvae. 38 The open surface design together with gradient soluble molecules were not only wellsuited for cell-based research, 39 but benefited zebrafish embryo-related investigation that even did not need a CO 2 culture incubator.…”

A microfluidic-based neurotoxin concentration gradient for the generation of an in vitro model of Parkinson’s disease

“…Although the gradient system showed sensitivity and specificity similar to those found in a multiwell system, it had several advantages compared to conventional multiwell system and previously developed microfluidic-based gradient generators, [34][35][36] including the short time required for gradient generation, low cost, highthroughput bioanalytical assays, and small amount of biological target and drug candidates. The system also offered features such as simplicity of design, portability, and fast operation.…”

A microfluidic platform for real-time and in situ monitoring of virus infection process

“…The tree-like microstructure 22 to generate different concentration gradients is a useful design to improve the throughput and has been used to study gene expression, cell response to stimuli and cell-based cancer drug screening. [23][24][25][26] The high-throughput capability of this design also makes microfluidic chip an attractive platform for the study of virus infection mechanism.…”