title: Biomechanical properties of nano-TiO(2) addition to a medical silicone elastomer: the effect of artificial ageing.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of TiO2 nanoparticles on the mechanical and anti-ageing properties of a medical silicone elastomer and to assess the biocompatibility of this novel combination.
  
  
  METHODS
  TiO2 (P25, Degussa, Germany) nanoparticles were mixed with the silicone elastomer (MDX4-4210, Dow Corning, USA) at 2%, 4%, and 6% (w/w) using silicone fluid as diluent (Q7-9180, Dow Corning, USA). Blank silicone elastomer served as the control material. The physical properties and biocompatibility of the composites were examined. The tensile strength was tested for 0% and 6% (w/w) before and after artificial ageing. SEM analysis was performed.
  
  
  RESULTS
  TiO2 nanoparticles improved the tensile strength and Shore A hardness of the silicone elastomer (P<0.05). However, a decrease in the elongation at break and tear strength was found for the 6% (w/w) composite (P<0.05). All the ageing methods had no effect on the tensile strength of the 6% (w/w) composite (P>0.05), but thermal ageing significantly decreased the tensile strength of the control group (P<0.05). Cellular viability assays indicated that the composite exhibited biocompatibility.
  
  
  CONCLUSIONS
  We obtained a promising restorative material which yields favourable physical and anti-ageing properties and is biocompatible in our in vitro cellular studies.
authors.affiliation: Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Jing
authors.affiliation: Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Shanyu
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. Electronic address: shaolongquan@smu.edu.cn.
authors.forename: Longquan
authors.initials: L
authors.lastname: Shao
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D001696:Biomechanical Phenomena; D002470:Cell Survival / Q000187:drug effects; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004548:Elasticity; D005347:Fibroblasts / Q000187:drug effects; D006244:Hardness; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D012826:Silicone Elastomers / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D012828:Silicones / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; C020964:MDX 4-4210; D012826:Silicone Elastomers; D012828:Silicones; C009495:titanium dioxide; D014025:Titanium
keywords: Artificial ageing; Biomechanical properties; Nano-TiO(2); Silicone elastomer