title: Kinetic study of release of silicon compounds from polysiloxane tissue expanders.
abstract: The release behavior of typical commercial tissue expanders has been examined by carrying out two kinds of experiments: 1) Determination of chemical nature and its modification after in vivo use by X-ray photoelectron spectroscopy for chemical analysis. This study has been paralleled by scanning electron microscopy with associated energy dispersive X-ray analysis of surface, as well as by silicon compounds analysis of tissues around implants. 2) Kinetic examination of silicon compounds released by the biomaterial in physiologic solution at 36 +/- 0.3 degrees C. Results of these investigations have shown independently that the starting material was not a filler-free, pure polymer, but a composite, reinforced elastomer, with the reinforcing agent most seemingly represented by silicon dioxide. Release of latter, with a relatively fast kinetics, is compatible with data of the simulating laboratory runs in the physiologic solution. All these facts seem to rule out any hypothesis of a prevailing siloxane oligomer migration. The correlation of kinetic and physicochemical tests with the in vivo behavior is discussed.
authors.affiliation: Institute of Pathology, Faculty of Medicine, University of Milan, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: Raimondi
authors.forename: C
authors.initials: C
authors.lastname: Sassara
authors.forename: I R
authors.initials: IR
authors.lastname: Bellobono
authors.forename: L
authors.initials: L
authors.lastname: Matturri
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D011138:Polytetrafluoroethylene / Q000031:analogs & derivatives / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D012995:Solubility; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D015625:Tissue Expansion Devices
chemical_list: D012828:Silicones; D012833:Siloxanes; C040378:poly(ethylene-tetrafluoroethylene); D011138:Polytetrafluoroethylene