Exploratory study on the micro-remodeling of dermal tissue / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the effect of three-dimensional structure of dermal matrix on biological behavior of fibroblasts (Fb) in the microcosmic perspective.</p><p><b>METHODS</b>The three-dimensional structure of dermal tissue was analyzed by plane geometric and trigonometric function. Microdots structure array with cell adhesion effect was designed by computer-assisted design software according to the adhesive and non-adhesive components of dermal tissue. Four sizes (8 microm x 3 microm, space 6 microm; 16 microm x 3 microm, space 6 microm; 16 microm x 5 microm, space 8 microm; 20 microm x 3 microm, space 2 microm) of micropier grid used for cell culture (MPGCC) with cell-adhesive microdots, built up with micro-pattern printing and molecule self-assembly method were used to culture dermal Fb. Fb cultured with cell culture matrix without micropier grid was set up as control. The expression of skeleton protein (alpha-SMA) of Fb, cell viability and cell secretion were detected with immunohistochemistry, fluorescent immunohistochemistry, MTT test and the hydroxyproline content assay.</p><p><b>RESULTS</b>The three-dimensional structure of dermal tissue could be simulated by MPGCC as shown in arithmetic analysis. Compared with those of control group [(12 +/- 3)% and (0.53 +/- 0.03) microg/mg, (0.35 +/- 0.04)], the expression of alpha-SMA [(49 +/- 3)%, (61 +/- 3)%, (47 +/- 4)%, (51 +/- 3)%] and the content of hydroxyproline [(0.95 +/- 0.04), (0.87 +/- 0.03), (0.81 +/- 0.03), (0.77 +/- 0.03) microg/mg] were increased significantly (P < 0.05), the cell viability of Fb (0.12 +/- 0.03, 0.13 +/- 0.04, 0.14 +/- 0.03, 0.19 +/- 0.03) cultured in MPGCC was decreased significantly (P < 0.05). When the parameters of micropier grid were changed, the expression of alpha-SMA, the cell viability and the content of hydroxyproline of Fb cultured in four sizes of MPGCC were also significantly changed as compared with one another (P < 0.05).</p><p><b>CONCLUSIONS</b>MPGCC may be the basic functional unit of dermal template, or unit of dermal template to call. Different three-dimensional circumstances for dermal tissue can result in different template effect and wound healing condition.</p>

Micro machining of micro-cantilever probes for efficient deposition for biochips / 生物工程学报

Biochip technology will bring a tremendous revolution to life science and medical research in 21 century. Microarray assays represent an essential technical advance in biomedical research. Recently, the demand for microarray assay technology has spring up. Therefore, low cost and flexible techniques are needed to meet specific requirements for increasingly integrated biochips. Also performance must be improved in terms of speed and sensitivity. To this end, promising approaches, mainly based on micro and nanotechnologies, have been developed. In this paper, the design and microfabrication of a novel type of micro-cantilever probe are introduced. These probes were fabricated using silicon dioxide by Micro-electromechanical System (MEMS) techniques, and they featured one micron split gap, microchannels and self-replenishing reservoirs. All fabricated micro-cantilever probe were tested on Nanoarrayer instrumentation. Cy3-streptavidin was loaded as biological sample and patterned on DSU gold surface. Results showed these probes were capable of generating high quality biological arrays with routine spot sizes of 2 - 3 microns and could deposit at least three thousand spots without reloading. The spot size could potentially achieve sub-micron when probe size was further shrunk down by the high-resolution lithography technique or more precise microfabrication technologies, such as E-beam lithography. To further improve sample loading efficiency, it is needed to modify the cantilever surface in order to better confine sample inside the microchannel and reservoir, which will be researched in the future.