Enhanced photoacoustic stability of gold nanorods by silica matrix confinement.
Photoacoustic tomography (PAT) has garnered much attention for its high contrast and excellent spatial resolution of perfused tissues. Gold nanorods (GNRs) have been employed to further enhance the imaging contrast of PAT. However, the photon fluences typically needed for PA wave induction often also result in GNR shape changes that significantly reduce the efficiency of acoustic wave generation. In this work, we propose, synthesize, and evaluate amorphous silica-coated gold nanorods (GNR-Si) in an effort to improve contrast agent stability and ameliorate efficiency loss during photoacoustic (PA) wave induction. TEM and optical absorption spectra measurements of GNR and GNR-Si show that encasing GNRs within amorphous silica provides substantial protection of nanorod conformation from thermal deformation. PA signals generated by GNR-Si demonstrate considerably greater resistance to degradation of signal intensity with repetitive pulsing than do uncoated GNRs, thereby enabling much longer, high-contrast imaging sessions than previously possible. The prolongation of high-contrast imaging, and biocompatibility and easy surface functionalization for targeting ligands afforded by amorphous silica, suggest GNR-Si to be potentially significant for the clinical translation of PAT.
Chen
Leng-Chun
LC
National Health Research Institutes, Division of Medical Engineering Research, Zhunan, Miaoli Country, Taiwan.
Wei
Chen-Wei
CW
Souris
Jeffrey S
JS
Cheng
Shih-Hsun
SH
Chen
Chin-Tu
CT
Yang
Chung-Shi
CS
Li
Pai-Chi
PC
Lo
Leu-Wei
LW
D000162:Acoustics; D003287:Contrast Media / Q000737:chemistry; D004355:Drug Stability; D006046:Gold / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D055095:Optics and Photonics; D012815:Signal Processing, Computer-Assisted; D012822:Silicon Dioxide / Q000737:chemistry*; D014054:Tomography / Q000379:methods*
D003287:Contrast Media; D006046:Gold; D012822:Silicon Dioxide