In vitro and in vivo protein sampling by combined microdialysis and ultrafiltration.

Cytokines, chemokines and growth factors regulate inflammation, resistance to infection and tissue repair. Understanding their function within tissues is a priority in evolving therapy for a number of disease processes. Yet, the existence of complex networks of these factors in the tissue microenvironment has made understanding of their interactions difficult. We demonstrate the capability of microdialysis probes to recover small proteins efficiently in vitro. Further we show that microdialysis of human tissues allows for protein recovery from tissue interstitial fluid. This technology, combined with a multiplexed immunoassay, facilitates the simultaneous measurement of cytokines and chemokines in response to injury in the oral mucosa of human subjects in vivo.