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1.1 project significance 项目意义
　　众所周知，有两种细胞粘连的细胞和细胞外基质（ECM）。对细胞粘附各种锚地依赖性细胞和调节细胞平衡是至关重要的It is well known that there are two kinds of cell adhesions: cell to cell and cell to extracellular matrix (ECM). Cell adhesion to the ECM is crucial for various anchorage dependent cells and regulates cellular homeostasis [1]. Hence it is also plays an important role in regulating most cellular process such as proliferation, migration, differentiation and apoptosis. https://www.51lunwen.org/Materialengineering/ Whilst significant contributions have been made in identifying the functional roles of key components involved in cell adhesion, a gap in understanding of the structure-function relationships still remains. To get a deeper understanding of cell adhesion, micropatternning has become a prevalent method for cell study since it is able to manipulate the conditions more precisely and can be used to improve standardization and quantification of cell behavior. Currently a large number of patterns with different shapes and sizes have been developed such as particles, grooves, and pits [2-4]. Previous studies have reported that random distributed nanoscale features increase cell adhesion whilst ordered nanostructure on 2-D surface decreases it [5]. This project is significant in that there is few article reported the effect of patterned random fibrillar patterns. By controlling the fiber density and dimension, different cell behaviors and morphology will be observed. These results have a potential contribution to the nanomedicine and bioengineering. Furthermore, since the electrospun nano-fibres are broadly used in scaffolds for tissue engineering, the cell assay may have a valuable conclusion for this field. This project also has potential further works since different electrospun fibres such as porous nano-fibres, flattened or ribbon-like nano-fibres, branched fibres, photoembossing fibres and hollow nano-fibres could also be applied for the patterning method.

1.2 Specific aims具体目标
　　The objective of this project is to develop a fibroid patterned substrate based on electrospinning. The central issue is to control the fiber deposition and dimension precisely. To achieve this approach, various electrospinning conditions including the polymer molecular weight, concentration and voltage were tested. The specific aims are addressed as follow.
　　Aim 1 is to develop a fibroid patterning technique based on electrospinning
　　This is the basic aim of this project. The hypothesis is if the fibres are placed on the substrates, after annealing (at a temperature between Tg and the melting point) the fibres deform and adsorb to the substrates more strongly, therefore protecting from the subsequent treatment. Etching the gold between the fibres is then carried out (suitable etching concentration and time were determined). After adding polymer brush as cell resistant background, a random fibroid patterned system was formed.
　　Aim 2 is to quantify the patterned substrate features with SEM
　　When preparing the patterned substrate, analysis of the resulting features is of particular importance for further studies. Therefore, we use image the substrates with normal optical microscope, atomic force microscope and scanning electron microscope. One hypothesis is that after etching, the fibroid protrusion diameter decreases compared with the electrospun fibres. Furthermore, a few of fibres may本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。