Phosphorescent iridium-containing nanomicelles: synthesis, characterization and preliminary applications in nanomedical imaging

Iridium-Functionalized Cellulose Microcrystals as a Novel Luminescent Biomaterial for Biocomposites

Microcrystalline cellulose (MCC) is an emerging material with outstanding properties in many scientific and industrial fields, in particular as an additive in composite materials. Its surface modification allows for the fine-tuning of its properties and the exploitation of these materials in a plethora of applications. In this paper, we present the covalent linkage of a luminescent Ir-complex onto the surface of MCC, representing the first incorporation of an organometallic luminescent probe in this biomaterial. This goal has been achieved with an easy and sustainable procedure, which employs a Bronsted-acid ionic liquid as a catalyst for the esterification reaction of -OH cellulose surface groups. The obtained luminescent cellulose microcrystals display high and stable emissions with the incorporation of only a small amount of iridium (III). Incorporation of MCC-Ir in dry and wet matrices, such as films and gels, has been also demonstrated, showing the maintenance of the luminescent properties even in possible final manufacturers.

An Application of Multivariate Data Analysis to Photoacoustic Imaging for the Spectral Unmixing of Gold Nanorods in Biological Tissues

Gold nanorods (GNRs) showed to be a suitable contrast agent in photoacoustics (PA), and are able to provide a tunable absorption contrast against background tissue, while a detectable PA signal can be generated from highly localized and targeted areas. A crucial issue for these imaging techniques is represented by the discrimination between exogenous and endogenous contrast and the assessment of the real PA signal magnitude. The application of image resolution/unmixing methods was implemented and optimized to recover the relative magnitude spectra and distribution maps of image constituents of the biological sample based on multivariate analysis (multivariate curve resolution-alternating least squares, MCR-ALS) in the presence of GNRs with tunable absorption properties. The proposed data analysis methodology is demonstrated on real PA images from experimental animal models and ex-vivo preparations.