Page 30 - libroRicercaIinnovazione_2016

Department of Engineering, ICT and Technologies for Energy and Transport Patent Title Chromophore formulations for use in the laser welding of biological tissues. Ref. CNR 1836 Assignee (s): CNR CNR Institute: IFAC Main Inventor: Roberto Pini Countries: IT Priority date: 31/10/2006 Abstract The invention relates to formulations of chromophores in semisolid or in solid forms, to be used for the staining of biological tissues, in order absorb the laser radiation in a selective and localized way, in welding processes of biological tissues induced by laser light. These procedures apply in surgical treatments for the suturing, repair and sealing of cuts and wounds in various types of tissue, such as cornea, skin and mucous membranes. Background The laser­induced welding techniques of biological tissues have been proposed in order to realize the suture of various types of tissue such as cornea, walls of blood vessels, skin, nerve tissue, etc. Laser irradiation of the tissues to be sutured is ofen associated with the topical application of an exogenous chromophore (for example a biocompatible dye), which has a high optical absorption at the wavelength of the laser used. Technology A formulation of a biocompatible dye for the sealing of corneal tissue with a diode laser emitting at a wavelength of 810 nm, which is capable of developing a pronounced discoloration of the cut walls, and in the case of tissues with a layered structure such as the skin, to allow staining of the walls of the cut in a differential manner, in order to compensate the different degree of optical absorption of different layers. Advantages and Applications The formulations of chromophores are used in the laser welding of biological tissues, in order to enhance the absorption of the laser radiation by the tissue and ensure a repeatable, selective and homogeneous thermal effect, induced by laser irradiation. This is key to making the clinical application of the laser welding technology safe, standardized and effective. Development stage The technique has been fully implemented, and tested in clinical trials for corneal laser welding in two Italian hospitals, afer receiving the approval of the ethics committees of these hospitals. 21