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Zhao Y.,CAS Institute of Electronics | Liu Q.,Tianjin Weikai Bioeng Ltd. | Liu Q.,Tianjin University of Science and Technology | Sun H.,Tianjin Weikai Bioeng Ltd. | And 8 more authors.
PLoS ONE | Year: 2016

Electrical property characterization of stem cells could be utilized as a potential label-free biophysical approach to evaluate the differentiation process. However, there has been a lack of technology or tools that can quantify the intrinsic cellular electrical markers (e.g., specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm)) for a large amount of stem cells or differentiated cells. In this paper, a microfluidic platform enabling the high-throughput quantification of Cspecific membrane and σcytoplasm from hundreds of single neural stem cells undergoing differentiation was developed to explore the feasibility to characterize the neural stem cell differentiation process without biochemical staining. Experimental quantification using biochemical markers (e.g., Nestin, Tubulin and GFAP) of neural stem cells confirmed the initiation of the differentiation process featured with gradual loss in cellular stemness and increased cell markers for neurons and glial cells. The recorded electrical properties of neural stem cells undergoing differentiation showed distinctive and unique patterns: 1) in the suspension culture before inducing differentiation, a large distribution and difference in σcytoplasm among individual neural stem cells was noticed, which indicated heterogeneity that may result from the nature of suspension culture of neurospheres; and 2) during the differentiation in adhering monolayer culture, significant changes and a large difference in Cspecific membrane were located indicating different expressions of membrane proteins during the differentiation process, and a small distribution difference in σcytoplasm was less significant that indicated the relatively consistent properties of cytoplasm during the culture. In summary, significant differences in Cspecific membrane and σcytoplasm were observed during the neural stem cell differentiation process, which may potentially be used as label-free biophysical markers to monitor this process. © 2016 Zhao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Wu Y.,Tianjin University of Traditional Chinese Medicine | Wu Y.,Tianjin International Joint Academy of Biomedicine | Sun J.,Tianjin University of Traditional Chinese Medicine | Sun J.,Tianjin International Joint Academy of Biomedicine | And 8 more authors.
Biotechnology Progress | Year: 2016

An in vitro three-dimensional (3D) cell culture system that can mimic organ and tissue structure and function in vivo will be of great benefit for drug discovery and toxicity testing. In this study, the neuroprotective properties of the three most prevalent flavonoid monomers extracted from EGb 761 (isorharmnetin, kaempferol, and quercetin) were investigated using the developed 3D stem cell-derived neural co-culture model. Rat neural stem cells were differentiated into co-culture of both neurons and astrocytes at an equal ratio in the developed 3D model and standard two-dimensional (2D) model using a two-step differentiation protocol for 14 days. The level of neuroprotective effect offered by each flavonoid was found to be aligned with its effect as an antioxidant and its ability to inhibit Caspase-3 activity in a dose-dependent manner. Cell exposure to quercetin (100 µM) following oxidative insult provided the highest levels of neuroprotection in both 2D and 3D models, comparable with exposure to 100 µM of Vitamin E, whilst exposure to isorhamnetin and kaempferol provided a reduced level of neuroprotection in both 2D and 3D models. At lower dosages (10 µM flavonoid concentration), the 3D model was more representative of results previously reported in vivo. The co-cultures of stem cell derived neurons and astrocytes in 3D hydrogel scaffolds as an in vitro neural model closely replicates in vivo results for routine neural drug toxicity and efficacy testing. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:735–744, 2016. © 2016 American Institute of Chemical Engineers

Li Z.,University of Oxford | Sun H.,Tianjin Weikai Bioeng Ltd | Zhang J.,Tianjin Weikai Bioeng Ltd | Zhang H.,Tianjin Weikai Bioeng Ltd | And 2 more authors.
PLoS ONE | Year: 2013

Increasing individuals diagnosed with type II diabetes pose a strong demand for the development of more effective anti-diabetic drugs. However, expensive, ethically controversial animal-based screening for anti-diabetic compounds is not always predictive of the human response. The use of in vitro cell-based models in research presents obviously ethical and cost advantages over in vivo models. This study was to develop an in vitro three-dimensional (3D) perfused culture model of islets (Islet TF) for maintaining viability and functionality longer for diabetic drug efficacy tests. Briefly fresh isolated rat islets were encapsulated in ultrapure alginate and the encapsulated islets were cultured in TissueFlex®, a multiple, parallel perfused microbioreactor system for 7 days. The encapsulated islets cultured statically in cell culture plates (3D static) and islets cultured in suspension (2D) were used as the comparisons. In this study we demonstrate for the first time that Islet TF model can maintain the in vitro islet viability, and more importantly, the elevated functionality in terms of insulin release and dynamic responses over a 7-day culture period. The Islet TF displays a high sensitivity in responding to drugs and drug dosages over conventional 2D and 3D static models. Actual drug administration in clinics could be simulated using the developed Islet TF model, and the patterns of insulin release response to the tested drugs were in agreement with the data obtained in vivo. Islet TF could be a more predictive in vitro model for routine short- and long-term anti-diabetic drug efficacy testing. © 2013 Li et al.

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