Cell biology is faced with challenges to create complex microenvironments to unravel intricate mechanisms of cell adhesion, focal adhesion, cell guidance, cell polarity, motility and migration, membrane dynamics, cell-cell interactions in co-culture, and mimicking morphogenesis in vitro or ex vivo.
These challenges can be overcome by protein printing on cell culture surfaces, and doing so at the micrometer scale. This approach has developed tremendously in the past few years and is now routinely used in biomedical research. To yield biologically relevant data, printed patterns of biomolecules should mimic the complexity of the in vivo cellular microenvironment. Micrometer-scale gradients of multiple proteins are thus highly desirable, however most micropatterning methods are still limited to only one type of molecule per pattern and do not allow for gradient patterning.
Here we present PRIMO, a maskless quantitative multi-protein photopatterning solution, which is based on the light-induced molecular adsorption of proteins (LIMAP) technology.
PRIMO relies on a high contrast and high resolution wide-field digital micromirror device (DMD) system coupled to an epifluorescence microscope to project custom-defined patterns of UV light onto a cell culture surface. Within seconds, a micrometer scale pattern, onto which proteins can adsorb, is generated by removing an antifouling agent (PEG) in an illuminated area. The remaining PEG coating, outside the defined patterns, allows for the sequential patterning of multiple proteins. Completely quantitative protein gradients of custom-defined shapes can also be patterned. In addition, PRIMO technology allows micromanufacturing by photopolymerization of PEG-Acrylate hydrogels including creating microfluidic channels (using PDMS molds), and subsequent 3D protein patterning on desired surfaces.
The PRIMO technology empowers biomedical research in neurobiology, immunology, stem cell biology, oncology, drug discovery, toxicology and tissue engineering. Several applications will be presented including spatially-controlled adhesion of single cells or cell populations, dynamic cell migration and 3D protein photopatterning.