title: Cyclo-DfKRG peptide modulates in vitro and in vivo behavior of human osteoprogenitor cells on titanium alloys.
abstract: The first aim of the present study was to investigate the capacity of a cyclo-DfKRG-coated hydroxyapatite-titanium alloy (Ti-HA-RGD) to activate in vitro human osteoprogenitor cells adhesion and differentiation. The second purpose was to examine in vivo the role of a autologous cell seeding on cyclo-DfKRG-functionalized materials to provide bone repair after implantation in femoral condyle of rabbits. Our in vitro results have demonstrated that both titanium alloy functionalized with hydroxyapatite (Ti-HA-RGD and Ti-HA) contributed to higher cell adhesion than titanium alloy alone respectively 85 and 55% vs 15% compared to tissue culture polystyrene after one hour of cell seeding. As for differentiation, after 3 days of culture, Ti-HA presented the highest increase of ALP mRNA of all surfaces studied. Ti-HA-RGD showed an intermediate value about half as high as Ti-HA. Moreover after 3 days, both Ti-HA and Ti-HA-RGD surfaces showed the highest increase of cbfa1 mRNA expression. Two weeks following implantation, in vivo findings revealed that percentage of lacunae contact observed with pre-cellularized Ti-HA-RGD samples remains significantly lower than with Ti-HA group (10.5+/-9.6 % vs 33.7+/-11.5 %, P<0.03). Meanwhile, RGD peptide coating had no significant additional effect on the bone implant contact and area. Moreover, histomorphometry analysis revealed that implantation of pre-cellularized RGD coated materials with ROP cells increased significantly peri-implant fibrous area (24+/-11.6% vs 3+/-1.7% for Ti-HA-RGD, P<0.02). RGD coatings demonstrated osteoblastic adhesion, differentiation and in vivo bone regeneration at most equivalent to HA coatings.
authors.affiliation: INSERM, U658, Hôpital Porte Madeleine, 1 rue Porte Madeleine, BP 2439, 45032 Orléans Cedex 1, France. stephane.pallu@chr-orleans.fr
authors.forename: S
authors.initials: S
authors.lastname: Pallu
authors.forename: J C
authors.initials: JC
authors.lastname: Fricain
authors.forename: R
authors.initials: R
authors.lastname: Bareille
authors.forename: C
authors.initials: C
authors.lastname: Bourget
authors.forename: M
authors.initials: M
authors.lastname: Dard
authors.forename: A
authors.initials: A
authors.lastname: Sewing
authors.forename: J
authors.initials: J
authors.lastname: Amédée
mesh_terms: D000497:Alloys; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000378:metabolism*; D011817:Rabbits; D011897:Random Allocation; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D013499:Surface Properties; D014025:Titanium
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D010456:Peptides, Cyclic; C505794:cyclo-DfKRG; D014025:Titanium