title: Controlled assembly of biodegradable plasmonic nanoclusters for near-infrared imaging and therapeutic applications.
abstract: Metal nanoparticles with surface plasmon resonance (SPR) in the near-infrared region (NIR) are of great interest for imaging and therapy. Presently, gold nanoparticles with NIR absorbance are typically larger than 50 nm, above the threshold size of approximately 5 nm required for efficient renal clearance. As these nanoparticles are not biodegradable, concerns about long-term toxicity have restricted their translation into the clinic. Here, we address this problem by developing a flexible platform for the kinetically controlled assembly of sub-5 nm ligand-coated gold particles to produce metal/polymer biodegradable nanoclusters smaller than 100 nm with strong NIR absorbance for multimodal application. A key novel feature of the proposed synthesis is the use of weakly adsorbing biodegradable polymers that allows tight control of nanocluster size and, in addition, results in nanoclusters with unprecedented metal loadings and thus optical functionality. Over time, the biodegradable polymer stabilizer degrades under physiological conditions that leads to disassembly of the nanoclusters into sub-5 nm primary gold particles which are favorable for efficient body clearance. This synthesis of polymer/inorganic nanoclusters combines the imaging contrast and therapeutic capabilities afforded by the NIR-active nanoparticle assembly with the biodegradability of a polymer stabilizer.
authors.affiliation: Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Jasmine M
authors.initials: JM
authors.lastname: Tam
authors.forename: Justina O
authors.initials: JO
authors.lastname: Tam
authors.forename: Avinash
authors.initials: A
authors.lastname: Murthy
authors.forename: Davis R
authors.initials: DR
authors.lastname: Ingram
authors.forename: Li Leo
authors.initials: LL
authors.lastname: Ma
authors.forename: Kort
authors.initials: K
authors.lastname: Travis
authors.forename: Keith P
authors.initials: KP
authors.lastname: Johnston
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Sokolov
mesh_terms: D000327:Adsorption; D000818:Animals; D002460:Cell Line; D006046:Gold / Q000737:chemistry; D007259:Infrared Rays; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D053761:Nanocomposites / Q000737:chemistry*; D011091:Polyesters; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry / Q000378:metabolism* / Q000627:therapeutic use* / Q000633:toxicity; D020349:Surface Plasmon Resonance
chemical_list: D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; D011092:Polyethylene Glycols; C033616:poly(lactide); D006046:Gold