Method of osteogenic differentiation in microfluidic tissue culture systems

Abstract

Microfluidic “organ-on-a-chip” devices have been developed with the aim to replicate human tissues in vitro. However, there is no option to quantitatively monitor biological processes that take place within the chip, over time. Destructive methods in order to analyze, tissue formation, gene expression, protein secretion etc. require the harvest of the “tissue” at a certain time point. Described herein are methods and compositions for non-destructive molecular imaging methods and systems in order to quantitatively monitor specific biological processes, over time, within the chip, without the need to harvest.

1 - 23 . (canceled) 
     
     
         24 . A method of culturing mesenchymal stem cells (MSCs) comprising flowing culture media over said MSCs in a microfluidic device to produce a higher number of proliferated MSCs in culture than in the absence of said flowing. 
     
     
         25 . The method of  claim 24 , wherein the microfluidic device comprises one or more channels. 
     
     
         26 . The method of  claim 24 , wherein the flow rate of said culture media is 30 ul per hour. 
     
     
         27 . The method of  claim 24 , wherein the microfluidic device comprises a membrane and said cells are attached to said membrane. 
     
     
         28 . The method of  claim 24 , wherein proliferation of the cells is monitored without disrupting the culture. 
     
     
         29 . The method of  claim 24 , wherein the cells are cultured for three weeks. 
     
     
         30 . The method of  claim 24 , further comprising,
 adding one or more labeling agents to the microfluidic device; and   detecting the labeling agent.   
     
     
         31 . The method of  claim 24 , further comprising,
 detecting one or more macromolecules secreted by the MSCs.   
     
     
         32 . A method of osteogenic differentiation comprising flowing osteogenic media over mesenchymal stem cells (MSCs) in an organ-on-a-chip device to produce a higher number of differentiated MSCs in culture that express osteocalcin and bone sialoprotein (bsp) osteogenic markers than in the absence of said flowing. 
     
     
         33 . The method of  claim 32 , wherein the microfluidic device comprises one or more channels. 
     
     
         34 . The method of  claim 32 , wherein the flow rate of said culture media is 30 ul per hour. 
     
     
         35 . The method of  claim 32 , wherein the microfluidic device comprises a membrane and said cells are attached to said membrane. 
     
     
         36 . The method of  claim 32 , wherein the cells are cultured for three weeks. 
     
     
         37 . The method of  claim 32 , further comprising,
 adding one or more labeling agents to the microfluidic device; and   detecting the labeling agent.