Microfluidic chip for analysis of cell motility and methods for using same
The present invention describes an integrated apparatus that enables identification of migratory cells directly from a specimen. The apparatus only requires a small number of cells to perform an assay and includes novel topographic features which can reliably differentiate between migratory and non-migratory cell populations in a sample. Both the spontaneous and chemotactic migration of cancer cells may be measured to distinguish between subpopulations within a tumor sample. The migratory cells identified using the apparatus and methods of the present invention may be separated and further analyzed to distinguish factors promoting metastasis within the population. Cells in the apparatus can be treated with chemotherapeutic or other agents to determine drug strategies to most strongly inhibit migration. The use of optically transparent materials in some embodiments allows a wide range of imaging techniques to be used for in situ imaging of migratory and non-migratory cells in the apparatus. The apparatus and methods of the present invention are useful for predicting the metastatic propensity of tumor cells and selecting optimal drugs for personalized therapies.
1. An apparatus for analysis of cellular motility in a sample comprising:
a) a substrate in the form of a chip having at least a first and second layer, wherein the first layer is a fluid layer having at least a first and second channel adjacent to each other on the fluid layer, the first and second channel each having an inlet end and an outlet end, the first channel comprises one or more inlets, each inlet having a reservoir which communicates with the inlet end of the first channel, the first channel also comprises one or more outlets, each outlet having a reservoir which communicates with the outlet end of the first channel, the second channel comprises an inlet having a reservoir which communicates with the inlet end of the second channel and also comprises an outlet having a reservoir which communicates with the outlet end of the second channel,
b) the first and second channels are in communication with each other through a plurality of migration channels, the migration channels are Y-shaped comprising a single inlet end at one end of the migration channel which is then bifurcated into two or more outlet ends at the other end of the migration channel, each inlet end of the migration channels are in communication with the second channel, and each of the one or more outlet ends of the migration channels are in communication with the first channel, and wherein the migration channels have a smaller width than either the first and second channels, and
c) the second layer is a coverslip layer comprising a transparent substrate, which is fitted over top of the fluid layer and is bonded to the first layer to make a liquid seal.
2. The apparatus of claim 1 , wherein the substrate is PDMS.
3. The apparatus of claim 1 , wherein the first and second channels have dimensions (h×w) of 50 μm×400 μm.
4. The apparatus of claim 1 , wherein the first channel has three inlets and one outlet.
5. The apparatus of claim 1 , wherein the second channel has one inlet and one outlet.
6. The apparatus of claim 1 , wherein the inlet has dimensions of 10 μm×20 μm.
7. The apparatus of claim 5 , wherein the two outlets have differing dimensions.
8. The apparatus of claim 7 , wherein the two outlets have dimensions of 10 μm×3 μm and 10 μm×20 μm.
9. The apparatus of claim 1 , wherein the migration channels have a length of 200-400 μm.
10. The apparatus of claim 9 , wherein the migration channels are adjacent to each other and spaced about 50 μm apart.
11. The apparatus of claim 1 , wherein the apparatus comprises from 1 to 400 migration channels.
12. The apparatus of claim 1 , wherein the inlet and outlet ends of the first and second channels have dimensions of 10 μm×100 μm.