TY - JOUR
T1 - Leveraging avidin-biotin interaction to quantify permeability property of microvessels-on-a-chip networks
AU - Gao, Feng
AU - Sun, Haoyu
AU - Li, Xiang
AU - He, Pingnian
N1 - Publisher Copyright:
© 2022 The Authors. Licensed under Creative Commons Attribution CC-BY 4.0. Published by the American Physiological Society.
PY - 2022/1
Y1 - 2022/1
N2 - Microvessels-on-a-chip have enabled in vitro studies to closely simulate in vivo microvessel environment. However, assessing microvessel permeability, a functional measure of microvascular exchange, has not been attainable in nonpermeable microfluidic platforms. This study developed a new approach that enables permeability coefficients (Ps) to be quantified in microvessels developed in nonpermeable chip platforms by integrating avidin-biotin technology. Microvessels were developed on biotinylated fibronectin-coated microfluidic channels. Solute transport was assessed by perfusing microvessels with fluorescence-labeled avidin. Avidin molecules that crossed endothelium were captured by substrate biotin and recorded with real-time confocal images. The Ps was derived from the rate of avidin-biotin accumulation at the substrate relative to solute concentration difference across microvessel wall. Avidin tracers with different physiochemical properties were used to characterize the barrier properties of the microvessel wall. The measured baseline Ps and inflammatory mediator-induced increases in Ps and endothelial cell (EC) [Ca2 þ ]i resembled those observed in intact microvessels. Importantly, the spatial accumulation of avidin-biotin at substrate defines the transport pathways. Glycocalyx layer is well formed on endothelium and its degradation increased transcellular transport without affecting EC junctions. This study demonstrated that in vitro microvessels developed in this simply designed microfluidics structurally possess in vivo-like glycocalyx layer and EC junctions and functionally recapitulate basal barrier properties and stimuli-induced responses observed in intact microvessels. This new approach overcomes the limitations of nonpermeable microfluidics and provides an easily executed highly reproducible in vitro microvessel model with in vivo microvessel functionality, suitable for a wide range of applications in blood and vascular research and drug development.
AB - Microvessels-on-a-chip have enabled in vitro studies to closely simulate in vivo microvessel environment. However, assessing microvessel permeability, a functional measure of microvascular exchange, has not been attainable in nonpermeable microfluidic platforms. This study developed a new approach that enables permeability coefficients (Ps) to be quantified in microvessels developed in nonpermeable chip platforms by integrating avidin-biotin technology. Microvessels were developed on biotinylated fibronectin-coated microfluidic channels. Solute transport was assessed by perfusing microvessels with fluorescence-labeled avidin. Avidin molecules that crossed endothelium were captured by substrate biotin and recorded with real-time confocal images. The Ps was derived from the rate of avidin-biotin accumulation at the substrate relative to solute concentration difference across microvessel wall. Avidin tracers with different physiochemical properties were used to characterize the barrier properties of the microvessel wall. The measured baseline Ps and inflammatory mediator-induced increases in Ps and endothelial cell (EC) [Ca2 þ ]i resembled those observed in intact microvessels. Importantly, the spatial accumulation of avidin-biotin at substrate defines the transport pathways. Glycocalyx layer is well formed on endothelium and its degradation increased transcellular transport without affecting EC junctions. This study demonstrated that in vitro microvessels developed in this simply designed microfluidics structurally possess in vivo-like glycocalyx layer and EC junctions and functionally recapitulate basal barrier properties and stimuli-induced responses observed in intact microvessels. This new approach overcomes the limitations of nonpermeable microfluidics and provides an easily executed highly reproducible in vitro microvessel model with in vivo microvessel functionality, suitable for a wide range of applications in blood and vascular research and drug development.
UR - http://www.scopus.com/inward/record.url?scp=85122257147&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85122257147&partnerID=8YFLogxK
U2 - 10.1152/AJPHEART.00478.2021
DO - 10.1152/AJPHEART.00478.2021
M3 - Article
C2 - 34767485
AN - SCOPUS:85122257147
SN - 0363-6135
VL - 322
SP - H71-H86
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 1
ER -