Capture, purification, and release of biological substances using a surface coating

Abstract

This invention relates to a surface coating for capture circulating rare cells, comprising a nonfouling composition to prevent the binding of non-specific cells and adsorption of serum components; a bioactive composition for binding the biological substance, such as circulating tumor cells; with or without a linker composition that binds the nonfouling and bioactive compositions. The invention also provide a surface coating for capture and purification of a biological substance, comprising a releasable composition to release the non-specific cells and other serum components; a bioactive composition for binding the biological substance, such as circulating tumor cells; with or without a linker composition that binds the releasable and bioactive compositions. The present invention also discloses a novel microfluidic chip, with specific patterned microstructures to create a flow disturbance and increase the capture rate of the biological substance.

1 .- 63 . (canceled) 
     
     
         64 . A microfluidic chip for selectively enriching rare cells, comprising:
 a first solid substrate and a second solid substrate, wherein at least one of the first and second solid substrates comprise a series of microstructures configured to interact with cells, and wherein the first and second solid substrates are configured to be bound parallel to one another; and   a surface coating for capturing the rare cells, wherein the surface coating comprises a non-fouling composition and a bioactive composition which selectively binds to the rare cells, wherein the non-fouling composition of the surface coating is non-covalently associated with the bioactive composition,   wherein each of the first and second solid substrates comprise the surface coating.   
     
     
         65 . The microfluidic chip of  claim 64 , wherein the microstructures are ordered such that progressing from one side of the microfluidic chip to the other side of the microfluidic chip longitudinally, the openings between the microstructures are staggered. 
     
     
         66 . The microfluidic chip of  claim 64 , wherein the bioactive composition comprises an antibody. 
     
     
         67 . The microfluidic chip of  claim 66 , wherein the antibody is a biotinylated EpCAM antibody. 
     
     
         68 . The microfluidic chip of  claim 64 , wherein the non-fouling composition comprises a lipid layer. 
     
     
         69 . The microfluidic chip of  claim 64 , wherein the two solid substrates comprises a glass substrate and a plastic substrate. 
     
     
         70 . The microfluidic chip of  claim 69 , wherein the glass substrate is located below the plastic substrate in a working configuration. 
     
     
         71 . The microfluidic chip of  claim 64 , wherein the first solid substrate comprises the series of microstructures, and wherein the first solid substrate is located above the second solid substrate in a working configuration. 
     
     
         72 . The microfluidic chip of  claim 64 , further comprising an adhesive for bonding the first solid substrate to the second solid substrate. 
     
     
         73 . The microfluidic chip of  claim 72 , wherein the adhesive comprises an inner hollow opening in a form of a channel. 
     
     
         74 . The microfluidic chip of  claim 73 , wherein the channel is configured to encompass the series of microstructures. 
     
     
         75 . The microfluidic chip of  claim 73 , wherein the channel of the adhesive determines a path for the rare cells to travel through for the microfluidic chip. 
     
     
         76 . The microfluidic chip of  claim 72 , wherein a thickness of the adhesive determines a height of a channel of the microfluidic chip. 
     
     
         77 . The microfluidic chip of  claim 64 , wherein the binding moiety comprises an antibody, and the antibody comprises a heavy chain and a light chain that binds EpCAM, wherein (a) the heavy chain comprises CDR1, CDR2, and CDR3 of SEQ ID No: 1, and (b) the light chain comprises CDR1, CDR2, and CDR3 of SEQ ID NO: 2. 
     
     
         78 . The microfluidic chip of  claim 64 , further comprising a syringe pump wherein the syringe pump is configured to apply buffer at a flow rate configured to release non-specific cells from the non-fouling layer without releasing cells selectively bound to the bioactive composition. 
     
     
         79 . The microfluidic chip of  claim 64 , further comprising a syringe pump configured to aid rinsing the microfluidic chip with a buffer at a shear force of about 2.5 to about 10 dyne/cm 2 . 
     
     
         80 . The microfluidic chip of  claim 64 , wherein the non-fouling composition is coupled to each of the first and second solid substrates by a surface linker. 
     
     
         81 . The microfluidic chip of  claim 64 , wherein the non-fouling composition is from 2 nm to 300 um thick. 
     
     
         82 . The microfluidic chip in accordance with  claim 64 , wherein the surface coating is attached to the solid substrate by one of the following non-covalent interactions: covalent bonding, hydrogen bonding, electrostatic interaction, hydrophilic-hydrophilic interaction, polar-polar interaction, magnetic force, or a combination thereof. 
     
     
         83 . The microfluidic chip of  claim 64 , wherein the non-fouling composition is configured to completely coat each of the first and second solid substrates.