Fibroblasts and tumor cells have been involved in the process of cancer development, progression and therapy. Here, we present a simple microfluidic device which enables to study the interaction between fibroblasts and tumor cells by indirect contact co-culture. The device is composed of multiple cell culture chambers which are connected by a parallel of cell migration regions, and it enables to realize different types of cells to communicate each other on the single device. In this work, human embryonic lung fibroblasts cells were observed to exhibit obvious migration towards tumor cells instead of normal epithelial cells on the co-culture device. Moreover, transdifferentiation of human embryonic lung fibroblast cells was recognized by the specific expression of a-smooth musle actin, indicating the effect of tumor cells on the behavior of fibroblasts. Furthermore, multiple types of cell co-culture can be demonstrated on the single device which enables to mimic the complicated microenviroment in vivo. The device is simple and easy to operate, which enables to realize real-time observation of cell migration after external stimulus. This microfluidic device allows for the characterization of various cellular events on a single device sequentially, faciliating the better understanding of interaction between heterotypic cells in a more complex microenvironment. Keywords:Co-culture / Microfluidic / Migration / Transdifferentiation DOI 10.1002/elps.200900776 IntroductionGrowing evidences demonstrate that tumor microenvironment including stromal cells, inflammatory cells, extracellular matrix and vessels plays an important role in the development, progression and therapy of cancer [1][2][3][4][5].Fibroblasts make up the largest number of stromal cells, which are continuously influenced by soluble factors secreted by tumor cells and their migration abilities can be enhanced by tumor cells. When fibroblasts are transdifferentiated, they become activated and were termed cancerassociated fibroblasts or myofibroblasts, which will have a significant effect on the proliferation, invasion and metastasis of tumor cells [6][7][8]. Therefore, it is of great importance to investigate the heterotypic cell interactions between tumor cells and fibroblasts. At present, co-culture is often used to investigate the interactions between heterotypic cells by using Transwell assay [9,10], in which two types of cells are separated into upper and lower chambers by a semi-permeable membrane, or by bathing cells in conditioned medium [11][12][13][14]. However, these assays are limited by the tedious manual operations which require several procedures, and they are all typical end-point assays, which are difficult to realize real-time observation. In addition, they still require large consumption of cells and reagents that are expensive in amount.Microfluidics has sparked increasing interests in cellbased biological and medical analysis, due to its miniaturization, low consumption of reagents, and capabilities to integrate various experimental op...

Our results demonstrated that HOTAIR mediated RCC progression in part through miR-124/ST8SIA4 axis, which functioned as a new prognostic biomarker in RCC.

The optical absorption properties and fluorescence properties of 3-hydroxy-2-(thiophen-2-yl)chromen-4-one (3-HTC) were simulated by the time-dependent density functional theory (TDDFT) method.

Quercetin can bring many benefits to skin based on its various bioactivities. However, the therapeutic effect of quercetin is limited due to the poor water solubility, pH instability, light instability, and skin permeation. The aim of the present work was applying essential oil-based microemulsions to improve the solubility, pH stability, photostability, and skin permeation of quercetin for topical application. Peppermint oil (PO-ME), clove oil (CO-ME), and rosemary oil (RMO-ME) were selected as model essential oils. Microemulsions composed of Cremophor EL/1,2-propanediol/essential oils (47:23:30, w/w) were selected as model formulations, based on the pseudo-ternary phase diagram and the characterizations. In the solubility study, the solubility of quercetin was improved dozens of times by microemulsions. Quercetin was found instable under alkaline condition, with 50% degraded in the solution of pH 13. However, PO-ME, CO-ME, and RMO-ME could protect quercetin from the hydroxide ions, with 47, 9, and 12% of quercetin degraded. In the photostability study, the essential oil-based microemulsions showed the capability of protecting quercetin from degradation under UV radiation. Where more than 67% of quercetin was degraded in aqueous solution, while less than 7% of quercetin degraded in microemulsions. At last, the in vitro skin permeation study showed that the essential oil-based microemulsions could enhance the permeation capacity of quercetin by 2.5-3 times compared to the aqueous solution. Hence, the prepared essential oil microemulsions could improve the solubility, pH stability, photostability, and skin permeation of quercetin, which will be beneficial for its topical application.