Development of a novel high throughput brain-on-chip with 3D structure and its application in evaluation of pesticide-induced-neurotoxicity / 生物工程学报

We designed and fabricated a novel high throughput brain-on-chip with three dimensional structure with the aim to simulate the in vivo three-dimensional growth environment for brain tissues. The chip consists of a porous filter and 3D brain cell particles, and is loaded into a conventional 96-well plate for use. The filter and the particle molds were fabricated by using computer modeling, 3D printing of positive mold and agarose-PDMS double reversal mold. The 3D cell particles were made by pouring and solidifying a suspension of mouse embryonic brain cells with sodium alginate into a cell particle mold, and then cutting the resulting hydrogel into pieces. The loaded brain-on-chip was used to determine the neurotoxicity of pesticides. The cell particles were exposed to 0, 10, 30, 50, 100 and 200 µmol/L of chlorpyrifos or imidacloprid, separated conveniently from the medium by removing the porous filter after cultivation. Subsequently, cell proliferation, acetylcholinesterase activity and lactate dehydrogenase release were determined for toxicity evaluation. The embryonic brain cells were able to grow and proliferate normally in the hydrogel particles loaded into the filter in a 96-well plate. Pesticide neurotoxicity test showed that both chlorpyrifos and imidacloprid presented dose-dependent inhibition on cell growth and proliferation. Moreover, the pesticides showed inhibition on acetylcholinesterase activity and increase release of lactate dehydrogenase. However, the effect of imidacloprid was significantly weaker than that of chlorpyrifos. In conclusion, a novel brain-on-chip was developed in this study, which can be used to efficiently assess the drug neurotoxicity, pharmacodynamics, and disease mechanism by combining with a microtiterplate reader.

High throughput detection and characterization of red blood cells deformability by combining optical tweezers with microfluidic technique / 生物医学工程学杂志

A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (

Identification of mouse brain neuropeptides by high throughput mass spectrometry / 生物工程学报

Neuropeptides play an important role in the physiological functions of the human body. The physiological activities such as pain, sleep, mood, learning and memory are affected by neuropeptides. Neuropeptides mainly exist in the nerve tissue of the body, and a small amount of them are distributed in body fluid and organs. At present, analysis of large-scale identification of neuropeptides in whole brain tissue is still challenging. Therefore, high-throughput detection of these neuropeptides is greatly significant to understand the composition and function of neuropeptides. In this study, 1 830 endogenous peptides and 99 novel putative neuropeptides were identified by extraction of endogenous peptides from whole brain tissue of mice by liquid phase tandem mass spectrometry (LC-MS / MS). The identification of these endogenous peptides provides not only a reference value in the treatment and mechanism studies of diseases and the development of drugs, but also the basis for the study of a new neuropeptides and their functions.

Early detection of the bloodstream infection bacteria based on MALDI-TOF MS / 解放军医学杂志

Objective To establish a clinical method for early detection of the bloodstream infection bacteria based on matrix-assisted laser ionization time of flight mass spectrometry (MALDI-TOF MS).Methods After consulting the Laboratory Information System statistics and domestic related literature,We chose 10 kinds of bacteria (Escherichia coli.,Pseudomonas aeruginosa,Acinetobacter baumannii,Klebsiella pneumoniae,Enterococcus faecium,Enterococcus faecalis,Staphylococcus aureus and Staphylococcus epidermidis,Proteus mirabilis,Streptococcus pneumoniae) as target.The MALDI-TOF MS was established using simulated bacterial infection blood samples.From March to May 2017,33 blood samples of suspected sepsis patients from Emergency Department,General Hospital of PLA,were tested.Results The MALDI-TOF MS whose detecting sensitivity was 100CFU/ml had the same negative detection rate with the blood culture (27cases/27cases,100％).Besides the 2 samples of Morganella morganii infection and Staphylococcus hominis infection were out of the range,the results of the remaining 4 positive samples were consistent (100％).Conclusion Compared to the blood culture and biochemical identification,MALDI-TOF MS can rapidly detect 10 kinds of bloodstream infection bacteria with high sensitivity and high accuracy.