title: Gold nanoshell/polysaccharide nanofilm for controlled laser-assisted tissue thermal ablation.
abstract: We report on the fabrication and characterization of a freestanding ultrathin, mucoadhesive gold nanoshell/polysaccharide multilayer nanocomposite (thermonanofilm, TNF), that can be used for controlled photothermal ablation of tissues through irradiation with near-infrared radiation (NIR) laser. The aim of this work is to provide a new strategy to precisely control particle concentration during photothermalization of cancerous lesions, since unpredictable and aspecific biodistributions still remains the central issue of inorganic nanoparticle-assisted photothermal ablation. Gold nanoshell encapsulation in polysaccharide matrix is achieved by drop casting deposition method combined with spin-assisted layer-by-layer (LbL) assembly. Submicrometric thickness of films ensures tissue adhesion. Basic laser-induced heating functionality has been demonstrated by in vitro TNF-mediated thermal ablation of human neuroblastoma cancer cells, evidenced by irreversible damage to cell membranes and nuclei. Ex vivo localized vaporization and carbonization of animal muscular tissue is also demonstrated by applying TNF onto tissue surface. Thermal distribution in the tissue reaches a steady state in a few seconds, with significant increases in temperature (ΔT > 50) occurring across an 1 mm span, ensuring control of local photothermalization and providing more safety and predictability with respect to traditional laser surgery. A steady-state model of tissue thermalization mediated by TNFs is also introduced, predicting the temperature distribution being known the absorbance of TNFs, the laser power, and the tissue thermal conductivity, thus providing useful guidelines in the development of TNFs. Thermonanofilms can find applications for local photothermal treatment of cancerous lesions and wherever high precision and control of heat treatment is required.
authors.affiliation: Center for Micro-BioRobotics, Istituto Italiano di Tecnologia , Pontedera, 56025, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Redolfi Riva
authors.forename: Andrea
authors.initials: A
authors.lastname: Desii
authors.forename: Edoardo
authors.initials: E
authors.lastname: Sinibaldi
authors.forename: Gianni
authors.initials: G
authors.lastname: Ciofani
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Piazza
authors.forename: Barbara
authors.initials: B
authors.lastname: Mazzolai
authors.forename: Virgilio
authors.initials: V
authors.lastname: Mattoli
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects; D002470:Cell Survival; D002645:Chickens; D006046:Gold / Q000737:chemistry*; D006801:Humans; D006979:Hyperthermia, Induced; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D057145:Nanoshells / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010777:Photochemistry; D011134:Polysaccharides / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared; D020349:Surface Plasmon Resonance; D013696:Temperature; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D014867:Water; D006046:Gold