title: Integrin-targeting block copolymer probes for two-photon fluorescence bioimaging.
abstract: Targeted molecular imaging with two-photon fluorescence microscopy (2PFM) is a powerful technique for chemical biology and, potentially, for noninvasive diagnosis and treatment of a number of diseases. The synthesis, photophysical studies, and bioimaging are reported for a versatile norbornene-based block copolymer multifunctional scaffold containing biocompatible (PEG), two-photon fluorescent dyes (fluorenyl) and targeting (cyclic-RGD peptide) moieties. The two bioconjugates, containing two different fluorenyl dyes and cRGDfK covalently attached to the polymer probe, formed a spherical micelle and self-assembled structure in water, for which size was analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Cell viability and 2PFM imaging of human epithelial U87MG cell lines that overexpress α(v)β(3) integrin was performed via incubation with the new probes, along with negative control studies using MCF-7 breast cancer cells and blocking experiments. 2PFM microscopy confirmed the high selectivity of the biocompatible probe in the integrin-rich area in the U87MF cells while blocking as well as negative control MCF-7 experiments confirmed the integrin-targeting ability of the new probes.
authors.affiliation: Department of Chemistry, The College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA.
authors.forename: Sanchita
authors.initials: S
authors.lastname: Biswas
authors.forename: Xuhua
authors.initials: X
authors.lastname: Wang
authors.forename: Alma R
authors.initials: AR
authors.lastname: Morales
authors.forename: Hyo-Yang
authors.initials: HY
authors.lastname: Ahn
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Belfield
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D016023:Integrins / Q000032:analysis* / Q000096:biosynthesis; D008856:Microscopy, Fluorescence; D057054:Molecular Imaging; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D015394:Molecular Structure; D010316:Particle Size; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D001672:Biocompatible Materials; D005456:Fluorescent Dyes; D016023:Integrins; D015335:Molecular Probes; D010456:Peptides, Cyclic; C507169:cyclic arginine-glycine-aspartic acid peptide