Advances in micro-electro-mechanical systems (MEMS) have led to an increased fabrication of micro-channels. Microfabrication techniques are utilized to develop microfluidic channels for continuous nutrition supply to cells inside a micro-environment. The ability of cells to build tissues and maintain tissue-specific functions depends on the interaction between cells and the extracellular matrix (ECM). SU-8 is a popular photosensitive epoxy-based polymer in MEMS. The patterning of bare SU-8 alone does not provide the appropriate ECM necessary to develop microsystems for biological applications. Manipulating the chemical composition of SU-8 will enhance the biological compatibility, giving the fabricated constructs the appropriate ECM needed to promote a functional tissue array. This article investigates three frequently used surface treatment techniques: (1) plasma treatment, (2) chemical reaction, and (3) deposition treatment to determine which surface treatment is the most beneficial for enhancing the biological properties of SU-8. The investigations presented in this article demonstrated that the plasma, gelatin, and sulfuric acid treatments have a potential to enhance SU-8's surface for biological application. Of course each treatment has their advantages and disadvantages (application dependent). Cell proliferation was studied with the use of the dye Almar Blue, and a micro-plate reader. After 14 days, cell proliferation to plasma treated surfaces was statistically significantly enhanced (p < 0.00001), compared to untreated surfaces. The plasma treated surface is suggested to be the better of the three treatments for biological enhancement followed by gelatin and sulfuric acid treatments, respectively.
Hamid, Qudus, Chengyang Wang, Jessica Snyder, Wei Sun
Journal of Biomedical Materials Research Part B: Applied Biomaterials