Bottom Line:
The residual rate of peptide was significantly larger in the P-S group than in the other three groups (P<.05).The result of this study suggests that coating doses depend on coating method. Residual amounts of RGD peptide were greater for the physical adsorption method than the chemical grafting method. 

Affiliation: Department of Prosthodontics, School of Dentistry, Dental Hospital, Dental Research Institute, Pusan National University, Yangsan, Republic of Korea. 

ABSTRACT

Purpose: The aim of this study was to evaluate the stability of arginine-glycine-aspartic acid (RGD) peptide coatings on implants by measuring the amount of peptide remaining after installation. 

Materials and methods: Fluorescent isothiocyanate (FITC)-fixed RGD peptide was coated onto anodized titanium implants (width 4 mm, length 10 mm) using a physical adsorption method (P) or a chemical grafting method (C).  Solid Rigid Polyurethane Foam (SRPF) was classified as either hard bone (H) or soft bone (S) according to its density.  Two pieces of artificial bone were fixed in a customized jig, and coated implants were installed at the center of the boundary between two pieces of artificial bone.  The test groups were classified as: P-H, P-S, C-H, or C-S. After each installation, implants were removed from the SRPF, and the residual amounts and rates of RGD peptide in implants were measured by fluorescence spectrometry.  The Kruskal-Wallis test was used for the statistical analysis (α=0.05). 

Results: Peptide-coating was identified by fluorescence microscopy and XPS.  Total coating amount was higher for physical adsorption than chemical grafting.  The residual rate of peptide was significantly larger in the P-S group than in the other three groups (P

Conclusion: The result of this study suggests that coating doses depend on coating method.  Residual amounts of RGD peptide were greater for the physical adsorption method than the chemical grafting method. 

Mentions:
Fig.  5 shows FE-SEM images of an anodized titanium surface after coating with RGD peptide.  The anodized titanium surface was porous and smooth with a roughness of 0.26 ± 0.03 µm.  However, surface structures (as determined by SEM) were similar in the experimental groups.  Fig.  6 shows fluorescent microscopic images after RGD peptide coating.  No fluorescent material was detected on the surfaces of uncoated titanium implants.  Fluorescent material was evident on all RGD peptide coated implant surfaces, with statistical significance.  Implant surfaces in the physical adsorption group fluoresced more than in the chemical grafting group.  Implant surfaces were yellower in the physical coated groups.  Green dot-like areas were sparsely present in both the physical adsorption and chemical grafting groups. 

Mentions:
Fig.  5 shows FE-SEM images of an anodized titanium surface after coating with RGD peptide.  The anodized titanium surface was porous and smooth with a roughness of 0.26 ± 0.03 µm.  However, surface structures (as determined by SEM) were similar in the experimental groups.  Fig.  6 shows fluorescent microscopic images after RGD peptide coating.  No fluorescent material was detected on the surfaces of uncoated titanium implants.  Fluorescent material was evident on all RGD peptide coated implant surfaces, with statistical significance.  Implant surfaces in the physical adsorption group fluoresced more than in the chemical grafting group.  Implant surfaces were yellower in the physical coated groups.  Green dot-like areas were sparsely present in both the physical adsorption and chemical grafting groups. 

Bottom Line:
The residual rate of peptide was significantly larger in the P-S group than in the other three groups (P<.05).The result of this study suggests that coating doses depend on coating method. Residual amounts of RGD peptide were greater for the physical adsorption method than the chemical grafting method. 

Affiliation:
Department of Prosthodontics, School of Dentistry, Dental Hospital, Dental Research Institute, Pusan National University, Yangsan, Republic of Korea. 

ABSTRACT

Purpose: The aim of this study was to evaluate the stability of arginine-glycine-aspartic acid (RGD) peptide coatings on implants by measuring the amount of peptide remaining after installation. 

Materials and methods: Fluorescent isothiocyanate (FITC)-fixed RGD peptide was coated onto anodized titanium implants (width 4 mm, length 10 mm) using a physical adsorption method (P) or a chemical grafting method (C).  Solid Rigid Polyurethane Foam (SRPF) was classified as either hard bone (H) or soft bone (S) according to its density.  Two pieces of artificial bone were fixed in a customized jig, and coated implants were installed at the center of the boundary between two pieces of artificial bone.  The test groups were classified as: P-H, P-S, C-H, or C-S. After each installation, implants were removed from the SRPF, and the residual amounts and rates of RGD peptide in implants were measured by fluorescence spectrometry.  The Kruskal-Wallis test was used for the statistical analysis (α=0.05). 

Results: Peptide-coating was identified by fluorescence microscopy and XPS.  Total coating amount was higher for physical adsorption than chemical grafting.  The residual rate of peptide was significantly larger in the P-S group than in the other three groups (P

Conclusion: The result of this study suggests that coating doses depend on coating method.  Residual amounts of RGD peptide were greater for the physical adsorption method than the chemical grafting method.