Two Different Strategies to Enhance Osseointegration in Porous Titanium: Inorganic Thermo-Chemical Treatment Versus Organic Coating by Peptide Adsorption

Int J Mol Sci. 2018 Aug 30;19(9):2574. doi: 10.3390/ijms19092574.

Abstract

In this study, highly-interconnected porous titanium implants were produced by powder sintering with different porous diameters and open interconnectivity. The actual foams were produced using high cost technologies: Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), and spark plasma sintering, and the porosity and/or interconnection was not optimized. The aim was to generate a bioactive surface on foams using two different strategies, based on inorganic thermo-chemical treatment and organic coating by peptide adsorption, to enhance osseointegration. Porosity was produced using NaCl as a space holder and polyethyleneglicol as a binder phase. Static and fatigue tests were performed in order to determine mechanical behaviors. Surface bioactivation was performed using a thermo-chemical treatment or by chemical adsorption with peptides. Osteoblast-like cells were cultured and cytotoxicity was measured. Bioactivated scaffolds and a control were implanted in the tibiae of rabbits. Histomorphometric evaluation was performed at 4 weeks after implantation. Interconnected porosity was 53% with an average diameter of 210 µm and an elastic modulus of around 1 GPa with good mechanical properties. The samples presented cell survival values close to 100% of viability. Newly formed bone was observed inside macropores, through interconnected porosity, and on the implant surface. Successful bone colonization of inner structure (40%) suggested good osteoconductive capability of the implant. Bioactivated foams showed better results than non-treated ones, suggesting both bioactivation strategies induce osteointegration capability.

Keywords: bioactive materials; osseointegration; porosity; titanium foams.

MeSH terms

  • Adsorption
  • Animals
  • Cell Survival
  • Cells, Cultured
  • Coated Materials, Biocompatible / chemistry*
  • Female
  • Osseointegration / drug effects*
  • Osteoblasts / cytology*
  • Porosity
  • Prostheses and Implants
  • Rabbits
  • Stress, Mechanical
  • Surface Properties
  • Temperature
  • Tibia / surgery*
  • Titanium / chemistry*

Substances

  • Coated Materials, Biocompatible
  • Titanium