(3-Aminopropyl)triethoxysilane (APTES), an aminosilane originally developed as an adsorbent for affinity chromatography, has developed into a versatile tool for improving surface chemistry in cell studies and microfluidic device fabrication. Following plasma cleaning, a treated material’s surface has high free energy, is free of contaminants and is decorated with hydrophilic functional groups. Over a long period of time, this high energy state abates as molecules rearrange, move back into the bulk and ultimately take on a lower energy configuration. Subsequent treatment with APTES swaps surface functional groups for the hydrophilic, amine carrying molecule . This allows for long term studies in which the surface hydrophilicity of a treated material is maintained.
The two primary applications of APTES surface functionalization are thermoplastic microfluidic device fabrication and the development of suitable microenvironments for cell studies. Thermoplastics such as polycarbonate (PC), polymethylmethacrylate (PMMA) and polystyrene (PS) are desirable materials for microfluidic devices because they can be produced at a high rate and low cost through thermomolding. After plasma cleaning and APTES treatment, thermoplastics are bonded to PDMS. These microfluidic devices retain their hydrophilicity for years. In cell studies, APTES is a foundational surface group that can be used to introduce essential extracellular matrix components such as collagen, glutaraldehyde and cell specific proteins. In the following papers, you will find examples of plasma treatment and APTES to enhanced material surface characteristics.
- Bachmann, B.; Spitz, S.; Rothbauer, M.; Jordan, C.; Purtscher, M.; Zirath, H.; Schuller, P.; Eilenberger, C.; Ali, S. F.; Mühleder, S.; Priglinger, E.; Harasek, M.; Redl, H.; Holnthoner, W. & Ertl, P. Engineering of three-dimensional pre-vascular networks within fibrin hydrogel constructs by microfluidic control over reciprocal cell signaling Biomicrofluidics, 2018, 12, 042216.
- Chuah, Y. J.; Kuddannaya, S.; Lee, M. H. A.; Zhang, Y. & Kang, Y. The effects of poly (dimethylsiloxane) surface silanization on the mesenchymal stem cell fate Biomater. Sci., Royal Society of Chemistry, 2015, 3, 383-390.
- Sigmundsson, K.; Ojala, J. R.; Öhman, M. K.; Österholm, A.-M.; Moreno-Moral, A.; Domogatskaya, A.; Chong, L. Y.; Sun, Y.; Chai, X.; Steele, J. A.; George, B.; Patarroyo, M.; Nilsson, A.-S.; Rodin, S.; Ghosh, S.; Stevens, M. M.; Petretto, E. & Tryggvason, K. Culturing functional pancreatic islets on α5-laminins and curative transplantation to diabetic mice Matrix Biology”, (2018) 70: 5-19.
- Zhang, F.; Sautter, K.; Larsen, A. M.; Findley, D. A.; Davis, R. C.; Samha, H. & Linford, M. R. “Chemical Vapor Deposition of Three Aminosilanes on Silicon Dioxide: Surface Characterization, Stability, Effects of Silane Concentration, and Cyanine Dye Adsorption”, Langmuir (2010) 26: 14648-14654.