Osteopontin (OPN) is an important protein to mediate improvements in the biocompatibility of C ion-implanted silicone rubber

PLoS One. 2014 Jun 9;9(6):e98320. doi: 10.1371/journal.pone.0098320. eCollection 2014.

Abstract

Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry*
  • Cell Adhesion / drug effects
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Coated Materials, Biocompatible / chemistry*
  • Coated Materials, Biocompatible / pharmacology*
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Gene Expression Regulation / drug effects
  • Humans
  • Matrix Metalloproteinase 9 / metabolism
  • Osteopontin / metabolism*
  • Silicone Elastomers / chemistry*
  • Silicone Elastomers / pharmacology*
  • Structure-Activity Relationship
  • Surface Properties

Substances

  • Coated Materials, Biocompatible
  • Silicone Elastomers
  • Osteopontin
  • Carbon
  • Matrix Metalloproteinase 9

Grants and funding

This work was funded by a grant from National Natural Science Foundation of China (81071574) (http://www.nsfc.gov.cn/publish/portal0/default.htm), a grant for Transformation of Scientific and Technological Achievements from Third Military Medical University (2012XZH05) (http://www.tmmu.edu.cn/), and the research start-up funds of Soochow University to Cong Cao (Q321506612)(http://www.suda.edu.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.