Plasmonic Nanoparticles with Quantitatively Controlled Bioconjugation for Photoacoustic Imaging of Live Cancer Cells

Abstract

Detection and imaging of single cancer cells is critical for cancer diagnosis and understanding of cellular dynamics. Photoacoustic imaging (PAI) provides a potential tool for the study of cancer cell dynamics, but faces the challenge that most cancer cells lack sufficient endogenous contrast. Here, a type of colloidal gold nanoparticles (AuNPs) are physically fabricated and are precisely functionalized with quantitative amounts of functional ligands (i.e., polyethyleneglycol (PEG) and (Arginine(R)–Glycine(G)–Aspartic(D))4 (RGD) peptides) to serve as an exogenous contrast agent for PAI of single cells. The functionalized AuNPs, with a fixed number of PEG but different RGD densities, are delivered into human prostate cancer cells. Radioactivity and photoacoustic analyses show that, although cellular uptake efficiency of the AuNPs linearly increases along with RGD density, photoacoustic signal generation efficiency does not and only maximize at a moderate RGD density. The functionalization of the AuNPs is in turn optimized based on the experimental finding, and single cancer cells are imaged using a custom photoacoustic microscopy with high‐resolution. The quantitatively functionalized AuNPs together with the high‐resolution PAI system provide a unique platform for the detection and imaging of single cancer cells, and may impact not only basic science but also clinical diagnostics on a range of cancers.

Plasmon-enhanced light–matter interactions and applications

“…Furthermore, specially functionalized gold nanoparticles have been developed in order to realize microscopic imaging of single cancer cells. 112…”

Impact of System Factors on the Performance of Photoacoustic Tomography Scanners

“…PAT can visualize biological samples at scales from organelles, cells, tissues, and organs to the small-animal whole body and can reveal multidimensional biological information, such as anatomical, functional, molecular, genetic, and metabolic data [1]. PAT has unique applications in a range of biomedical fields [4,5], such as cell biology [6][7][8][9], neurology [10][11][12], oncology [13,14], rheumatology [15], and ophthalmology [16,17]. Both basic sciences and clinical translations involving PAT are expected to grow in the future.…”

Combating acoustic heterogeneity in photoacoustic computed tomography: A review

“…[1][2][3][4] The imaging modality holds great promise for a range of biomedical applications, such as early detection of cancer, 5,6 in°ammation evaluation, 7 biopsy guidance, 8,9 retinal imaging, 10 and cellular imaging. 11,12 In PACT, the energy of a laser pulse is absorbed by biological tissues, which will induce a rapid thermal expansion and then excite ultrasound waves. The ultrasound signals travel through the tissue and are detected by ultrasound transducers arranged in a certain detection geometry for¯nal image reconstruction.…”