pH-responsive ratiometric photoacoustic imaging of polyaniline nanoparticle-coated needle for targeted cancer biopsy

• Type of Material: Article
• Authors: Ayoung Choe, Emory University; David Qin, Emory University; Anthony M Yu, Emory University; Euisuk Chung, School of Electrical and Computer Engineering; Anamik Jhunjhunwala, Emory University; Julian A Rose, Emory University; Stanislav Emelianov, Emory University
• Language: English
• Date: 2023-06-01
• Publisher: Elsevier GmbH.
• Publication Version: Final Published Version
• Copyright Statement: © 2023 The Authors. Published by Elsevier GmbH.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.pacs.2023.100500
• Title of Journal or Parent Work: Photoacoustics
• Volume: 31
• Start Page: 100500
• End Page: 100500
• Keywords: PH sensors; Photoacoustic contrast agents; Ratiometric analysis; Polyaniline nanoparticles
• Research Categories: Engineering, Biomedical

Abstract

Cancer microenvironment exhibits lower pH compared to healthy tissues, a characteristic which can be exploited using a pH-responsive needle to increase the accuracy of cancer biopsy. A needle, coated with pH-responsive polyaniline (PANI) nanoparticles (PANI-needle), is developed for the minimally invasive and quantitative pH analysis of tissue based on ratiometric photoacoustic (PA) imaging. The ratiometric PA signal from the PANI-needle within the 850–700 nm wavelength range shows a linear response as pH changes from 7.5 to 6.5. Owing to the high surface area of nanostructured PANI, the PA signal of PANI-needle exhibits a fast and reversible response of less than a few seconds. In a tissue-mimicking hydrogel phantom composed of two regions with different pH, PA ratios of PANI-needle successfully differentiate the local pH. The PANI-needle coupled with ultrasound-guided PA imaging is a promising technology for detection of malignant tissue through quantitative pH analysis during needle biopsy.