title: Highly stable polymer coated nano-clustered silver plates: a multimodal optical contrast agent for biomedical imaging.
abstract: Here, we present a new optical contrast agent based on silver nanoplate clusters embedded inside of a polymer nano matrix. Unlike nanosphere clusters, which have been well studied, nanoplate clusters have unique properties due to the different possible orientations of interaction between the individual plates, resulting in a significant broadening of the absorption spectra. These nanoclusters were immobilized inside of a polymer cladding so as to maintain their stability and optical properties under in vivo conditions. The polymer-coated silver nanoplate clusters show a lower toxicity compared to the uncoated nanoparticles. At high nanoparticle concentrations, cell death occurs mostly due to apoptosis. These nanoparticles were used for targeted fluorescence imaging in a rat glioma cell line by incorporating a fluorescent dye into the matrix, followed by conjugation of a tumor targeting an F3 peptide. We further used these nanoparticles as photoacoustic contrast agents in vivo to enhance the contrast of the vasculature structures in a rat ear model. We observed a contrast enhancement of over 90% following the nanoparticle injection. It is also shown that these NPs can serve as efficient contrast agents, with specific targeting abilities for broadband multimodal imaging that are usable for diagnostic applications and that extend into use as therapeutic agents as well.
authors.affiliation: Department of Chemistry and BioPhysics, University of Michigan, Ann Arbor, USA.
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Ray
authors.forename: Ananya
authors.initials: A
authors.lastname: Mukundan
authors.forename: Zhixing
authors.initials: Z
authors.lastname: Xie
authors.forename: Leshern
authors.initials: L
authors.lastname: Karamchand
authors.forename: Xueding
authors.initials: X
authors.lastname: Wang
authors.forename: Raoul
authors.initials: R
authors.lastname: Kopelman
mesh_terms: D000818:Animals; D017209:Apoptosis; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D003287:Contrast Media / Q000138:chemical synthesis*; D003952:Diagnostic Imaging / Q000379:methods*; D018316:Gliosarcoma / Q000175:diagnosis* / Q000378:metabolism; D053758:Nanoparticles / Q000009:adverse effects / Q000648:ultrastructure; D018384:Oxidative Stress; D011108:Polymers / Q000138:chemical synthesis; D051381:Rats; D012834:Silver
chemical_list: D003287:Contrast Media; D011108:Polymers; D012834:Silver