Non-invasive Photoacoustic Screening of Blood Vasculature during Anti-angiogenesis using CAM Assay

Suhel Khan¹, Priyanka Pathak², Srivathsan Vasudevan^1*, and Debasis Nayak²

Abstract: There is a strong need for non-invasive detection of normal tissue from diseased one and a better understanding of the factors involved in the infection’s growth. Continuous monitoring of tissue samples at different time points is highly desirable. We demonstrate using the photoacoustic spectral response technique (PASR) for in situ analysis in a developing chicken embryo as a model(CAM) for anti-angiogenesis and vascular development. The photoacoustic technique is an emerging modality that is based on the acoustic detection of optical absorption of biological samples. The detected PA signals and their spectral response were used as a signature to determine the vasculature development pathology. Continuous monitoring of vascular growth and an anti-drug (Cisplatin) effect on vasculature has been done. PASR was investigated for the 10^th day, 11^th day, and 12^th day control and inoculated egg samples. It shows that the dominant frequency of the PA spectral response for 10^th day control and inoculated eggs lies between 0.45-0.52 MHz, whereas for 11^th day and 12^th day control eggs lie at 0.61 ±0.152 MHz and 0.67 ±0.001 MHz, respectively. The inoculated 11^th and 12^th day eggs lie at 0.35 ±0.156 MHz and 0.16 ±0.004 MHz, respectively. PASR could monitor the change in growth within a span of one day, which was not possible through the conventional imaging approach. This would open up a potential diagnostic technique for continuous monitoring of CAM assays.