title: Photoactivatable BODIPYs designed to monitor the dynamics of supramolecular nanocarriers.
abstract: Self-assembling nanoparticles of amphiphilic polymers can transport hydrophobic molecules across hydrophilic media and, as a result, can be valuable delivery vehicles for a diversity of biomedical applications. Strategies to monitor their dynamics noninvasively and in real time are, therefore, essential to investigate their translocation within soft matrices and, possibly, rationalize the mechanisms responsible for their diffusion in biological media. In this context, we designed molecular guests with photoactivatable fluorescence for these supramolecular hosts and demonstrated that the activation of the fluorescent cargo, under optical control, permits the tracking of the nanocarrier translocation across hydrogel matrices with the sequential acquisition of fluorescence images. In addition, the mild illumination conditions sufficient to implement these operating principles permit fluorescence activation within developing Drosophila melanogaster embryos and enable the monitoring of the loaded nanocarriers for long periods of time with no cytotoxic effects and no noticeable influence on embryogenesis. These photoresponsive compounds combine a borondipyrromethene (BODIPY) chromophore and a photocleavable oxazine within their covalent skeleton. Under illumination at an appropriate activation wavelength, the oxazine ring cleaves irreversibly to bring the adjacent BODIPY fragment in conjugation with an indole heterocycle. This structural transformation shifts bathochromically the BODIPY absorption and permits the selective excitation of the photochemical product with concomitant fluorescence. In fact, these operating principles allow the photoactivation of BODIPY fluorescence with large brightness and infinite contrast. Thus, our innovative structural design translates into activatable fluorophores with excellent photochemical and photophysical properties as well as provides access to a general mechanism for the real-time tracking of supramolecular nanocarriers in hydrophilic matrices.
authors: Yang
authors: Y
authors: Zhang
authors: Subramani
authors: S
authors: Swaminathan
authors: Sicheng
authors: S
authors: Tang
authors: Jaume
authors: J
authors: Garcia-Amorós
authors: ‡Analytical Imaging Core Facility, Diabetes Research Institute, University of Miami, 1450 NW 10th Avenue, Miami, Florida 33136, United States.
authors: Marcia
authors: M
authors: Boulina
authors: Burjor
authors: B
authors: Captain
authors: James D
authors: JD
authors: Baker
authors: Françisco M
authors: FM
authors: Raymo
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000737:chemistry*; D004331:Drosophila melanogaster / Q000196:embryology; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D015195:Drug Design; D005456:Fluorescent Dyes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D061848:Optical Imaging; D010078:Oxazines / Q000737:chemistry; D055668:Photochemical Processes
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D004337:Drug Carriers; D005456:Fluorescent Dyes; D007211:Indoles; D010078:Oxazines