Article

Prototype of an in vitro model of the microcirculation.

Visual and Circulatory Biophysics Laboratory, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Microvascular Research (impact factor: 2.83). 04/2003; 65(2):132-6. pp.132-6
Source: PubMed

ABSTRACT We have used microfabrication technology to construct a network of microchannels, patterned after the dimensions and architecture of the mammalian microcirculation. The network is cast in transparent silicone elastomer and the channels are coated with silanated mPEG to provide lubrication. Flow of red and white blood cells through the network is readily visualized by the use of high-speed digital image acquisition. The acquired sequences of high-quality images are used to calculate hematocrits and rates of red cell movement in the microchannels. Our prototype system has significant advantages over scaled-up room-size experimental systems in that it permits experimentation with actual human blood cells. Experiments can be carried out under well-controlled conditions in a network of microchannels with precisely known dimensions using cell suspensions of defined composition. Moreover, there is no need to counteract or anticipate the host's adaptive responses that may confound live animal experiments. Notwithstanding its limitations, the current prototype demonstrates certain features characteristic of the microcirculation, such as parachute and bullet shapes of red cells deformed in capillary channels, rouleaux formation, plasma skimming, and the utilization of collateral flow pathways due to flow obstruction caused by a white cell blocking a microchannel. We present this device as a prototype scale-to-scale model of the mammalian microcirculation. Limitations of the system as well as a variety of possible applications are described.

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Keywords

acquired sequences
 
actual human blood cells
 
animal experiments
 
bullet shapes
 
calculate hematocrits
 
capillary channels
 
collateral flow pathways
 
current prototype
 
high-quality images
 
high-speed digital image acquisition
 
host's adaptive responses
 
microchannels
 
prototype scale-to-scale model
 
prototype system
 
red cell movement
 
red cells deformed
 
rouleaux formation
 
scaled-up room-size experimental systems
 
white blood cells
 
white cell