title: Optical detection of indocyanine green encapsulated biocompatible poly (lactic-co-glycolic) acid nanoparticles with photothermal optical coherence tomography.
abstract: We describe a functional imaging paradigm that uses photothermal optical coherence tomography (PT-OCT) to detect indocyanine green (ICG)-encapsulated biocompatible poly(lactic-co-glycolic) acid (PLGA) nanoparticles embedded in highly scattering tissue phantoms with high resolution and sensitivity. The ICG-loaded PLGA nanoparticles were fabricated using a modified emulsification solvent diffusion method. With a 20 kHz axial scan rate, PT-OCT based on spectral-domain interferometric configuration at 1310 nm was used to detect phase changes induced by a 808 nm photothermal excitation of ICG-encapsulated PLGA nanoparticles. An algorithm based on Fourier transform analysis of differential phase of the spectral interferogram was developed for detecting the depth resolved localized photothermal signal. Excellent contrast difference was observed with PT-OCT between phantoms containing different concentrations of ICG-encapsulated PLGA nanoparticles. This technique has the potential to provide simultaneous structural and molecular-targeted imaging with excellent signal-to-noise for various clinical applications.
authors.affiliation: Department of Biomedical Engineering, Oregon Health and Science University, 3303 SW Bond Ave., Portland, Oregon 97239, USA. mollysub@ohsu.edu
authors.forename: Hrebesh M
authors.initials: HM
authors.lastname: Subhash
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Smith
authors.forename: Owen J T
authors.initials: OJ
authors.lastname: McCarty
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D005240:Feasibility Studies; D007208:Indocyanine Green / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D019047:Phantoms, Imaging; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D007208:Indocyanine Green