Patterned surfaces offer unique benefits for studying cell biology and especially in elucidating the mechanisms by which cells interact with each other and the components of their immediate surroundings. Our lab has implemented several novel surface fabrication strategies, including patterning of glass surfaces by laser scanning lithography (LSL), that allow us to generate complex arrays of different cell-reactive factors such as adhesion ligands and whole proteins. These materials present biological features in the nanoscale range, providing precise control over the physical interactions of cultured cells.
Directing stem cell behavior on biologically inspired micropatterned surfaces
Stem cells are of great interest for regenerative medicine and have shown promise in the treatment of various medical conditions. In order to produce effective stem cell therapies, it is necessary to develop methods to guide stem cell differentiation. We are interested in exploring the importance of focal adhesions for bone marrow-derived mesenchymal stem cell (MSC) differentiation. Focal adhesions are large protein complexes that are critical for transmitting intracellular and extracellular forces and greatly influence cell signaling and therefore, cell behavior. We have identified significant differences in adhesion site configuration of fully differentiated cells of the mesoderm lineage, including adipocytes and osteoblasts. We hypothesize that if we restrict MSC adhesions such that they mimic the adhesions formed by these fully differentiated cells, the MSCs will differentiate into these particular cell types. We are using laser scanning lithography, an innovative photothermal patterning technique, to develop protein micropatterns that mimic the adhesions formed by adipocytes and osteoblasts. After culturing MSCs on these patterns, we monitor the expression of lineage specific differentiation markers.
Human osteoblast adhesion site mimetic pattern
A.) Normal human osteoblast (red = actin, green = vinculin, blue = nucleus, scale bar = 35 μm), B.) Osteoblast adhesion sites based on vinculin staining (scale bar = 35 μm), C.) Fibronectin pattern mimicking osteoblast adhesions developed using laser-scanning lithography (scale bar = 35 μm), D.) Bone marrow-derived mesenchymal stem cell on osteoblast adhesion site pattern (scale bar = 50 μm)
- Slater JH, Miller JS, Yu SS, West JL. "Fabrication of Multifaceted Micropatterned Surfaces with Laser Scanning Lithography." Advanced Functional Materials. 2011 May 31; 21.