Covalently‐linked hyaluronan promotes bone formation around Ti implants in a rabbit model

Abstract

The goal of this study was the in vivo evaluation of nanoporous titanium (Ti) implants bearing a covalently linked surface hyaluronan (HA) layer. Implant surface topography and surface chemistry were previously evaluated by scanning electron micorscopy and X-ray photoelectron spectroscopy. Results showed that the surface modification process did not affect surface topography, yielding a homogeneously HA-coated nanotextured implant surface. In vivo evaluation of implants in both cortical and trabecular bone of rabbit femurs showed a significant improvement of both bone-to-implant contact and bone ingrowth at HA-bearing implant interfaces at 4 weeks. The improvement in osteointegration rate was particularly evident in the marrow-rich trabecular bone (bone-to-implant contact: control 22.5%; HA-coated 69.0%, p < 0.01). Mechanical testing (push-out test) and evaluation of interfacial bone microhardness confirmed a faster bone maturation around HA-coated implants (Bone Maturation Index: control 79.1%; HA-coated 90.6%, p < 0.05). Suggestions based on the biochemical role of HA are presented to account for the observed behavior. ß

Nanocoating of Titanium Implant Surfaces with Organic Molecules. Polysaccharides Including Glycosaminoglycans

“…20 Mechanical push-out test evaluation of interfacial bone microhardness of titanium surface coated with HA showed faster bone maturation around coated than non-coated implants. 17 A faster bone healing, increased mechanical strength and increased boneimplant bonding were registered at sites with chitosan and apatite coated implants compared to non-coated controls. 36 According to the authors chitosan has osteoconductive properties and induced a higher bone metabolism.…”

“…13 19 A positive effect in early bone formation has also been demonstrated in a study, where rabbits had inserted titanium implants coated with hyaluronan (HA), another glycasaminoglycan. 17 The HA coating significantly increased bone contact (BIC) and bone ingrowth (BMD) in the cortical bone as well as in trabecular bone compared to controls without coating.…”

“…1 Polysaccharides, including glycosaminoglycans have been used for implant surface coating, based on both the direct and indirect adhesion mechanism. [12][13][14][15][16][17][18][19][20][21] The advantage of polysaccharides compared to proteins as nanocoating material is that they stay longer at the coated surface and therefore have a cell attracting effect for a longer time. 14 22 23 Thus, the properties enable polysaccharides to carry signal molecules and support biologically active substances.…”

Bioactive nanocomposite coatings of collagen/hydroxyapatite on titanium substrates

“…Recent studies concerning collagen coatings on Ti hard-tissue implants have demonstrated their effective roles in stimulating cellular responses [11], increasing bone remodeling [12,13], and improving bone growth and bone-implant contact [14]. Therefore, hybrids of collagen and HA have greater potential for clinical applications than their pure HA or collagen equivalents, because they benefit from the advantageous properties of both materials, while retaining a similar composition and structure to that of human hard tissues.…”

One-step modification of nano-hydroxyapatite coating on titanium surface by hydrothermal method

“…Such surface modifications could alter the physical, chemical and biological properties of the surface [3][4][5][6][7]. So far, the surface modification methods mainly included sandblasting and acid-etching [8], alkalineheat treatment [9], anodization, calcium phosphate coating and immobilization of bioactive molecules such as hyaluronic acid [10], collagen [11,12], BMP [13], etc.…”