Measurement of human red blood cell deformability using a single micropore on a thin Si/sub 3/N/sub 4/ film

Abstract

The filtration method for the evaluation of the RBC deformability has been further refined to simulate the deformations encountered in the recticuloendothelial system (in particular the spleen), a recognized site of aged and sickled cells removal. The core of the developed measuring system is a very thin (0.4 micron thick) filter that consists of single micropore (diameters down to 1 micron) on a Si3N4 film which has been constructed using silicon microfabrication techniques. Individual RBC's deformability is quantified measuring the cell pore passage time. From one blood sample 200 passage times are analyzed by a computer, displaying mean and median values as deformability indexes, and class and cumulative histograms for studying the passage times distribution. In this paper the effectiveness of the developed system as a routine clinical evaluation tool is demonstrated by studying several factors that are known to affect the RBC deformability, such as temperature, addition of diamide and glutaraldehyde, and blood storage conditions. In addition, it is experimentally demonstrated that the human RBC can traverse a pore with a diameter as small as 1 micron when the pore length is very short, thus broadening the experimental conditions under which the RBC deformability (fluidity) can be studied.

Bio-inspired Cell Deformability Monitoring Chips Based on Strain Dependent Digital Lysis Rates

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Microfabricated implants for applications in therapeutic delivery, tissue engineering, and biosensing

“…The novelty of microfabrication arises mainly in the miniaturization of features, a design element that was not available until the 1950’s with the advent of integrated circuit technology and not applied to biology until the 1990’s 13. Miniaturization can aid in fitting the implant into a small space, such as between tissue.…”

Microtechnologies for Drug Delivery

“…The novelty of microfabrication arises mainly in the miniaturization of features, a design element that was not available until the 1950s with the advent of integrated circuit technology and not applied to biology until the 1990s [ 10 ] . The mass fabrication techniques developed for integrated circuit technology carry over to many or all of the features of microfabricated therapeutic delivery devices.…”