Session: 07-08-03: Biomedical Devices, Sensors, and Actuators III

Paper Number: 172826

Electro-Deformation Spectroscopy for Detecting Red Blood Cell Changes in a Huntington's Disease Mouse Model 

Prior studies showed that the shape of red blood cells (RBCs) is affected in Huntington’s disease (HD), creating acanthocytes (spikey-shaped cells). Although biochemical changes in blood, such as elevated levels of mutant huntingtin (mHTT), protein and lipid peroxidation, have been well documented, the effects of HD on the biophysical properties of RBCs have not been studied yet. Electro-deformation spectroscopy (EDS) is a newly developed technique that measures cell elongation due to electrical forces across a range of electrical frequencies. This method allows characterization of individual cells for their mechanical and electrical properties, including cell membrane elongation and cellular biophysical properties, such as membrane shear modulus, cytoplasm conductivity, and membrane permittivity. 

     In this study, blood samples from 12 transgenic line R6/2 mouse model of HD were collected each month and analyzed for a period of 3 months. The collected data were compared with those obtained from 3 wild-type mice. EDS measurements were performed in a microfluidic device that consists of an indium tin oxide microelectrode array (44 μm gap and 106 μm band) glass chip and a polydimethylsiloxane channel with an inlet and outlet of 3 mm and 1 mm, respectively. Blood cells were suspended in an isosmotic working medium made of 0.3% (w/v) dextrose and 8.5% (w/v) sucrose with electrical conductivity adjusted to 400 mS/cm by phosphate-buffered saline. To induce electro-deformation, a cell suspension was loaded into the microfluidic device and excited by a sinusoid waveform of 1.5 V (root mean square value) across various frequencies ranging from 15 MHz to 800 kHz. Images of RBC electro-deformation behavior were analyzed with ImageJ software. Each cell was fit into an ellipse, and its major (a) and minor (b) axes were measured. The elliptical shift factor (ESF = a/b) was used to quantify cell elongation. Custom MATLAB code was used to extract biophysical properties using the average EDS value per mouse in each month, by matching theoretical values with experimental measurements. 

     The findings showed that RBC elongation does not provide a clear distinction between the test and wild-type groups; however, the HD group showed significantly higher cytoplasm conductivity and membrane shear modulus compared to the control group. These parameters were found to increase each month, indicating that cells become more rigid with the progression of the disease. 

     In summary, this study showed that EDS is a useful tool for assessing biomechanical and biophysical properties of animal blood cells. The observed alterations in RBC biophysical properties, combined with reduced weight gain, collectively highlight the effects of HD and indicate these measures as potential markers for monitoring disease advancement. 

Presenting Author: Liliana Ponkratova Florida Atlantic University

Presenting Author Biography: Liliana has a BS in Biotechnology and Bioengineering from V. N. Karazin Kharkiv National University, Ukraine. She earned an MS in Biomedical Engineering at Florida Atlantic University. Currently, she is pursuing her PhD in Mechanical Engineering at Florida Atlantic University.

Authors:

Liliana Ponkratova Florida Atlantic University
E Du Florida Atlantic University
Hongyuan Xu Florida Atlantic University
Jianning Wei Florida Atlantic University