title: Surface modification of SU-8 for enhanced cell attachment and proliferation within microfluidic chips.
abstract: 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.
authors.affiliation: Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania.
authors.forename: Qudus
authors.initials: Q
authors.lastname: Hamid
authors.forename: Chengyang
authors.initials: C
authors.lastname: Wang
authors.forename: Jessica
authors.initials: J
authors.lastname: Snyder
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
mesh_terms: D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D006801:Humans; D046210:Microfluidic Analytical Techniques
chemical_list: D020099:Coated Materials, Biocompatible; D004852:Epoxy Compounds
keywords: SU-8; biomaterials availability; biosensors/biochips; microfluidic; surface modification