Nanoporous Titania Coating of Microwell Chips for Stem Cell Culture and Analysis

Abstract

Stem cell research is today an active and promising field of research. To learn more about the biology of stem cells, technical improvements are needed such as tools to study stem cells in order to characterize them further and to gain insights to the molecular regulations of their maintenance, differentiation and identification. Common procedure when studying stem cells is to coat the surface where the stem cells are to be cultured with organic materials like matri-gel, poly-L-lysine and fibronectin. The resulting coating is usually relatively fragile and it is difficult to know if the coating is evenly distributed. In addition, these forms of coatings cannot be sterilized and re-used, but must be added as an initial, time-consuming step in the daily protocol. A microwell chip with hundreds of 500 nl wells has recently been shown to be a useful tool for stem cell culturing. This platform is here modified to facilitate and improve the coating conditions for adherent cell culture. A robust and highly porous film of TiO2 is deposited in the wells prior cell seeding. TiO2 is known to be biocompatible and provides a surface that is even and well characterized, simple to produce and re-usable. Furthermore it enables the microwell chips to be stored pre-coated for longer periods of time before use. We investigated the growth of rat mesenchymal stem cells on nanoporous titania films and found that they proliferated much faster than on conventional coatings. The combination of the robust TiO2 coating of the microwell chip enables thousands of individually separated single, or clones of, stem cells to be studied simultaneously and opens up the possibility for more user-friendly cell culturing.

Keywords

• stem cells
• titania
• biocompatibility
• microwells
• surface modifications