Prevention of Cell Adhesion

To reduce cell adhesion during cell studies in microchips, various coating methods have developed. For instance, a polyacrylamide film was photopattemed on acrylate-coated glass, using 3-(trimethyoxysilyl)propylacrylate. This coating reduced the fraction of adhesion as follows CATH.a cells (1.05-0.25), U937 cells (0.99-0.11), and Jurkat T cells (0.05-0.04) [623], 

In one report, Pluronics surfactant (tri-block copolymer of PEO-PPO-PEO) was used to prevent cell adhesion in a chip. This is because the center PPO block is hydrophobic and thus shields any hydrophobic surface on the chip. In addition, the end PEO groups are neutral but very hydrophilic, and will not interact with proteins and cells [278]. 

In another report PEG, which is a water-soluble, non-toxic, and non-immu-nogenic polymer, has been evaluated for its use as a non-biofouling coating for Si-based chips [912]. 

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Cell surface-bound mucins can be involved in cell adhesion and also in the prevention of cell adhesion. For example, mucins participate in the control of cell adhesion mediated by integrin and E-cadherin. Some of these mucins are shed from the cell surface and are found in the bloodstream where they can play a role in the control of the immune system. For example, MUCl from breast cancer cells is shed and can be isolated from the serum. Depending on the nature of the mucins, they can block natural killer cell-mediated cell lysis and the action of cytotoxic lymphocytes. In cancer and other diseases affecting the epithelium, mucin gene expression is often altered. Especially, MUCl mucin is highly expressed on tumorigenic ductal epithelial cells. 

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