Paolo Matteini, Fulvio Ratto, Francesca Rossi, Giacomo Rossi, Giuseppe Esposito, Alfredo Puca, Alessio Albanese, and Giulio Maira- Institute of Applied Physics “Nello Carrara”, Italian National Research Council- University of Camerino, Faculty of Veterinary Medicine- Catholic University School of Medicine, Institute of Neurosurgery
We prove the first application of near-infrared-absorbing gold nanorods (GNRs) for in vivo laser closure of a rabbit carotid artery. GNRs are first functionalized with a biopolymeric shell and then embedded in hyaluronan, which gives a stabilized and handy laser-activable formulation. Four rabbits undergo closure of a 3-mm longitudinal incision performed on the carotid artery by means of a 810-nm diode laser in conjunction with the topical application of the GNRs composite. An effective surgery is obtained by using a 40-W/cm2 laser power density. The histological and electron microscopy evaluation after a 30-day follow-up demonstrates complete healing of the treated arteries with full re-endothelization at the site of GNRs application. The absence of microgranuloma formation and/or dystrophic calcification is evidence that no host reaction to nanoparticles interspersed through the vascular tissue occurred. The observation of a reshaping and associated blue shift of the NIR absorption band of GNRs after laser treatment supports the occurrence of a self-terminating process, and thus of additional safety of the minimally invasive laser procedure. This study underlines the feasibility of using GNRs for in vivo laser soldering applications, which represents a step forward toward the introduction of nanotechnology-based therapies in minimally invasive clinical practices. … After irradiation, the samples were subject to spectromicroscopy by a homemade setup composed of a transmission microscope (model DM 2500 by Leica Microsystems GmbH, Germany), a visible-NIR spectrometer (model EPP200 by Stellarnet Incorporated, Tampa, Florida .
