Estimating cell concentration in three-dimensional engineered tissues using high frequency quantitative ultrasound.

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Ultrasound Technology

Background:

• Traditional methods like histology and biochemical assays for cell concentration are destructive.
• These destructive methods prevent longitudinal monitoring of engineered tissues during fabrication.

Purpose of the Study:

• Develop high-frequency quantitative ultrasound techniques.
• Enable non-destructive estimation of cell concentration in 3-D engineered tissue constructs.

Main Methods:

• Acquired high-frequency ultrasound backscatter measurements from cell-embedded 3-D agarose hydrogels.
• Utilized broadband single-element transducers (30 and 38 MHz) across 13-47 MHz frequency range.
• Calculated the integrated backscatter coefficient (IBC) to estimate cell concentration.

Main Results:

• The integrated backscatter coefficient (IBC) demonstrated a linear correlation with increasing cell concentration.
• Established optimal region of interest dimensions for <20% error in cell concentration estimates.
• Generated quantitative images of cell concentration, revealing regional differences.

Conclusions:

• High-frequency quantitative ultrasound offers a rapid, non-invasive, and non-destructive method for cell concentration assessment in 3-D tissue constructs.
• This technique facilitates real-time monitoring and quality control during tissue engineering processes.