title: Exploiting novel sterilization techniques for porous polyurethane scaffolds.
abstract: Porous polyurethane (PU) structures raise increasing interest as scaffolds in tissue engineering applications. Understanding the effects of sterilization on their properties is mandatory to assess their potential use in the clinical practice. The aim of this work is the evaluation of the effects of two innovative sterilization techniques (i.e. plasma, Sterrad(®) system, and ozone) on the morphological, chemico-physical and mechanical properties of a PU foam synthesized by gas foaming, using water as expanding agent. In addition, possible toxic effects of the sterilization were evaluated by in vitro cytotoxicity tests. Plasma sterilization did not affect the morphological and mechanical properties of the PU foam, but caused at some extent degradative phenomena, as detected by infrared spectroscopy. Ozone sterilization had a major effect on foam morphology, causing the formation of new small pores, and stronger degradation and oxidation on the structure of the material. These modifications affected the mechanical properties of the sterilized PU foam too. Even though, no cytotoxic effects were observed after both plasma and ozone sterilization, as confirmed by the good values of cell viability assessed by Alamar Blue assay. The results here obtained can help in understanding the effects of sterilization procedures on porous polymeric scaffolds, and how the scaffold morphology, in particular porosity, can influence the effects of sterilization, and viceversa.
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, P.zza Leonardo da Vinci 32, 20133, Milan, Italy, serena.bertoldi@polimi.it.
authors.forename: Serena
authors.initials: S
authors.lastname: Bertoldi
authors.forename: Silvia
authors.initials: S
authors.lastname: Farè
authors.forename: Håvard Jostein
authors.initials: HJ
authors.lastname: Haugen
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Tanzi
mesh_terms: D019245:Compressive Strength; D055119:Elastic Modulus; D008422:Materials Testing; D010126:Ozone / Q000737:chemistry / Q000494:pharmacology*; D058626:Plasma Gases / Q000737:chemistry / Q000494:pharmacology*; D011140:Polyurethanes / Q000737:chemistry*; D016062:Porosity; D013242:Sterilization / Q000379:methods*; D054457:Tissue Scaffolds / Q000382:microbiology*
chemical_list: D058626:Plasma Gases; D011140:Polyurethanes; D010126:Ozone