Ex vivo microfluidic analysis of biologic samples

Abstract

Systems and methods for culturing and monitoring, ex vivo, pharmacologic and metabolic response in a biological sample, including receiving at a fluidic apparatus the biological sample retrieved from the patient, retaining the biological sample within a channel of the fluidic apparatus, providing for the culture of the biological sample within the channel of the fluidic apparatus, flowing a fluid past the biological sample, retrieving and analyzing the fluid to determine a pharmacologic and/or metabolic response of the sample.

What is claimed is: 
     
         1 . A fluidic apparatus comprising:
 a substrate;   a channel located within the substrate to receive a biological sample and to carry a fluid flow across the biological sample;   a concave retaining barrier located within the channel to retain the biological sample, wherein the geometry of the concave retaining barrier is configured to allow fluid flowing through the channel to induce interstitial flow of the fluid through the biological sample to perfuse the biological sample with the fluid while maintaining shear rates at the biological sample within a range of between about 0.375 and 0.500 dynes/cm 2 .   
     
     
         2 . The apparatus of  claim 1 , wherein the concave retaining barrier comprises a plurality of posts extending from the floor of the channel substantially to top of the channel. 
     
     
         3 . The apparatus of  claim 2 , wherein the plurality of posts includes between three to ten free-standing posts extending substantially the full height of the channel and at least one embedded post extending out from a channel sidewall. 
     
     
         4 . The apparatus of  claim 3 , wherein the concave retaining barrier comprises five free-standing posts and two embedded posts. 
     
     
         5 . The apparatus of any one of  claims 2 , wherein adjacent posts are spaced apart from one another to have a lateral separation across of the between about 20 μm-about 40 μm. 
     
     
         5 . The apparatus of  claim 2 , wherein the shortest distance between any two adjacent posts is between about 65 μm-85 μm. 
     
     
         6 . The apparatus of  claim 3 , wherein an outer most free-standing post of the plurality of posts is spaced between about 65 μm-85 μm away from a nearest channel sidewall. 
     
     
         7 . The apparatus of  claim 2 , comprising a fluid supply configured to flow a fluid through the channel. 
     
     
         8 . The apparatus of  claim 7 , wherein the fluid supply comprises a closed loop fluid supply configured to reroute fluid already flowed through a distal end of the channel back through a proximal end of the channel. 
     
     
         9 . The apparatus of  claim 7 , comprising a fluid extractor configured to extract a sample of the fluid after it has flowed through to channel. 
     
     
         10 . The apparatus of  claim 2 , comprising an optical sensor for optically monitoring a state of a biological sample located within the retaining barrier. 
     
     
         11 . The apparatus of  claim 1 , comprising the biological sample, wherein the biological sample is between about 100 and about 500 microns in diameter. 
     
     
         12 . A method of assessing the impact of a pharmacological agent on an ex vivo tissue sample, comprising:
 introducing a tissue sample having a diameter of between about 100-500 microns into a concave retaining barrier formed in a flow channel,   introducing a fluid including the pharmacological agent at a proximal end of the channel such that the fluid flows through the channel across the tissue sample, thereby inducing interstitial flow of the fluid through the tissue sample and the retaining barrier and such that the fluid perfuses through the tissue sample;   collecting a portion of the fluid at a distal end of the channel;   and analyzing the collected fluid portion for evidence of pharmacological impact on the tissue sample.   
     
     
         13 . The method of  claim 12 , wherein the evidence of pharmacological impact comprises evidence of cell death. 
     
     
         14 . The method of  claim 12 , further comprises capturing an image of the tissue sample after flowing the fluid through the channel and analyzing the captured image for evidence of pharmacological impact on the tissue sample. 
     
     
         15 . The method of  claim 12 , comprising flowing the fluid through the channel at a rate of about 500 microliters per hour. 
     
     
         16 . The method of  claim 12 , wherein the tissue sample comprises a tissue sample collected using fine-needle biopsy (FNBA). 
     
     
         17 . The method of  claim 12 , wherein the concave retaining barrier comprises a plurality of posts extending from the floor of the channel substantially to top of the channel. 
     
     
         18 . The method of  claim 17 , wherein the plurality of posts includes between three to ten free-standing posts extending substantially the full height of the channel and at least one embedded post extending out from a channel sidewall. 
     
     
         19 . The method of  claim 17 , further comprising:
 introducing a second tissue sample having a diameter of between about 100-500 microns into a second concave retaining barrier formed in a second flow channel,   introducing a second fluid including a second pharmacological agent at a proximal end of the second channel such that the second fluid flows through the second channel across the second tissue sample and the second concave retaining barrier and such that the second fluid perfuses through the second tissue sample;   collecting a portion of the second fluid at a distal end of the second channel;   analyzing the collected portion of the second fluid for evidence of pharmacological impact on the second tissue sample; and   comparing the pharmacological impacts of the first and second pharmacological agents.   
     
     
         20 . The method of  claim 19 , comprising selecting one of the first and second pharmacological agents for treatment of an animal based on the comparison of the pharmacological impacts. 
     
     
         21 . The method of  claim 20 , wherein the animal is a source of the first and second tissue samples.