title: Method for tracking nanogel particles in vivo and in vitro.
abstract: Hydrogels made of N-isopropylacrylamide (NIPA) can be synthesized in the form of highly monodispersed nanoparticles. After synthesis, NIPA hydrogel nanoparticles (nanogels) can be labeled by Alexa Fluor 488 carboxylic acid, 2,3,5,6-tetrafluorophenyl ester through amine-terminated functional groups. This choice of dye is complementary to other biological labeling methods for in vivo studies. When the nanogel/dye nanoparticles are injected into rabbits, they can be imaged via tissue sectioning and confocal microscopy, while nanoparticle concentration can be determined by fluorescent microplate assays. Time-course persistence of nanoparticles in the circulatory system can be readily tracked by direct assay of plasma and urine samples using 485 nm excitation and 538 emission wavelengths to keep background fluorescence to nearly the same level as that found using an empty well. Depending upon how the nanoparticles are injected, circulatory system concentrations can reach high concentrations and diminish to low levels or gradually increase and gradually decrease over time. Injection in the femoral artery results in a rapid spike in circulating nanogel/dye concentration, while injection into the renal artery results in a more gradual increase.
authors.affiliation: Harrington Department of Bioengineering, Arizona State University, Tempe, AZ, USA.
authors.forename: Brandon L
authors.initials: BL
authors.lastname: Seal
authors.forename: Yeong-Hau H
authors.initials: YH
authors.lastname: Lien
authors.forename: Carla
authors.initials: C
authors.lastname: Mazar
authors.forename: Mohamad W
authors.initials: MW
authors.lastname: Salkini
authors.forename: Tong
authors.initials: T
authors.lastname: Cai
authors.forename: Zhibing
authors.initials: Z
authors.lastname: Hu
authors.forename: Manuel
authors.initials: M
authors.lastname: Marquez
authors.forename: Antonio A
authors.initials: AA
authors.lastname: Garcia
mesh_terms: D000178:Acrylamides / Q000097:blood / Q000138:chemical synthesis* / Q000652:urine; D000818:Animals; D005263:Femoral Artery; D005456:Fluorescent Dyes / Q000737:chemistry; D005464:Fluorobenzenes / Q000097:blood / Q000737:chemistry* / Q000652:urine; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry*; D007269:Injections, Intra-Arterial; D053758:Nanoparticles / Q000737:chemistry*; D011817:Rabbits; D012077:Renal Artery; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: D000178:Acrylamides; C513915:AlexaFluor 488 carboxylic acid tetrafluorophenyl ester; D005456:Fluorescent Dyes; D005464:Fluorobenzenes; D020100:Hydrogels; C067295:N-isopropylacrylamide