title: Photoacoustic imaging of living mouse brain vasculature using hollow gold nanospheres.
abstract: Photoacoustic tomography (PAT) also referred to as optoacoustic tomography (OAT) is a hybrid imaging modality that employs nonionizing optical radiation and ultrasonic detection. Here, we describe the application of a new class of optical contrast agents based on mesoscopic hollow gold nanospheres (HAuNS) to PAT. HAuNS are approximately 40 nm in diameter with a hollow interior and consist of a thin gold wall. They display strong resonance absorption tuned to the near-infrared (NIR) range, with an absorption peak at 800 nm, whose photoacoustic efficiency is significantly greater than that of blood. Following surface conjugation with thiolated poly(ethylene glycol), the pegylated HAuNS (PEG-HAuNS) had distribution and elimination half-lives of 1.38 +/- 0.38 and 71.82 +/- 30.46 h, respectively. Compared with PAT images based on the intrinsic optical contrast in nude mice, the PAT images acquired within 2 h after intravenous administration of PEG-HAuNS showed the brain vasculature with greater clarity and detail. The image depicted brain blood vessels as small as approximately 100 mum in diameter using PEG-HAuNS as contrast agents. Preliminary results showed no acute toxicity to the liver, spleen, or kidneys in mice following a single imaging dose of PEG-HAuNS. Our results indicate that PEG-HAuNS are promising contrast agents for PAT, with high spatial resolution and enhanced sensitivity.
authors.affiliation: Department of Experimental Diagnostic Imaging, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Qian
authors.initials: Q
authors.lastname: Huang
authors.forename: Geng
authors.initials: G
authors.lastname: Ku
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Wen
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.forename: Dmitry
authors.initials: D
authors.lastname: Guzatov
authors.forename: Peter
authors.initials: P
authors.lastname: Brecht
authors.forename: Richard
authors.initials: R
authors.lastname: Su
authors.forename: Alexander
authors.initials: A
authors.lastname: Oraevsky
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Li
mesh_terms: D000042:Absorption / Q000187:drug effects; D000162:Acoustics; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000187:drug effects; D001931:Brain Mapping; D002470:Cell Survival / Q000187:drug effects; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D006046:Gold / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008027:Light; D051379:Mice; D054118:Nanospheres / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D009928:Organ Specificity / Q000187:drug effects; D011092:Polyethylene Glycols / Q000493:pharmacokinetics / Q000633:toxicity; D013997:Time Factors; D014018:Tissue Distribution / Q000187:drug effects; D018675:Toxicity Tests; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects
chemical_list: D011092:Polyethylene Glycols; D006046:Gold