Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Tatjana Repenko - , Leibniz Institute for Interactive Materials (Author)
  • Anne Rix - , RWTH Aachen University (Author)
  • Alexander Nedilko - , RWTH Aachen University (Author)
  • Jonas Rose - , Leibniz Institute for Interactive Materials (Author)
  • Alina Hermann - , Leibniz Institute for Interactive Materials (Author)
  • Rostislav Vinokur - , Leibniz Institute for Interactive Materials (Author)
  • Sheila Moli - , Leibniz Institute for Interactive Materials (Author)
  • Roberto Cao-Milàn - , University of Havana (Author)
  • Martin Mayer - , Center for Advancing Electronics Dresden (cfaed), Leibniz Institute of Polymer Research Dresden (Author)
  • Gero von Plessen - , RWTH Aachen University (Author)
  • Andreas Fery - , Center for Advancing Electronics Dresden (cfaed), Leibniz Institute of Polymer Research Dresden (Author)
  • Laura De Laporte - , Leibniz Institute for Interactive Materials (Author)
  • Wiltrud Lederle - , RWTH Aachen University (Author)
  • Dmitry N. Chigrin - , Leibniz Institute for Interactive Materials, RWTH Aachen University (Author)
  • Alexander J.C. Kuehne - , Leibniz Institute for Interactive Materials (Author)

Abstract

Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low-cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross-section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod-shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.

Details

Original languageEnglish
Article number1705607
JournalAdvanced functional materials
Volume28
Issue number7
Publication statusPublished - 14 Feb 2018
Peer-reviewedYes

Keywords

Keywords

  • contrast agents, core-shell particles, intestinal imaging, photothermal, thermal confinement