Grafting RGD containing peptides onto hydroxyapatite to promote osteoblastic cells adhesion

Abstract

Ceramics possess osteoconductive properties but exhibit no intrinsic osteoinductive capacity. Consequently, they are unable to induce new bone formation in extra osseous sites. In order to develop bone substitutes with osteogenic properties, one promising approach consists of creating hybrid materials by associating in vitro biomaterials with osteoprogenitor cells. With this aim, we have developed a novel strategy of biomimetic modification to enhance osseointegration of hydroxyapatite (HA) implants. RGD-containing peptides displaying different conformations (linear GRGDSPC and cyclo-DfKRG) were grafted onto HA surface by means of a three-step reaction procedure: silanisation with APTES, cross-linking with N-succinimidyl-3-maleimidopropionate and finally immobilisation of peptides thanks to thiol bonding. Whole process was performed in anhydrous conditions to ensure the reproducibility of the chemical functionalisation. The three-step reaction procedure was characterised by high resolution X-ray photoelectron spectroscopy. Efficiency of this biomimetic modification was finally demonstrated by measuring the adhesion of osteoprogenitor cells isolated from HBMSC onto HA surface.

Carbonate hydroxyapatite functionalization: a comparative study towards (bio)molecules fixation

“…The spectrum of CHA is dominated by the 960 and 1030-1100 cm 21 bands due to the bending of PO 4 32 . In addition, peaks around 1455 and 1415 cm 21 to N-H stretching vibration and NH 2 bending mode of free NH 2 groups, respectively, are particularly significant for the determination of the presence of amine functionalization of CHA [45]. From IR spectra, it can be highlighted that the use of TEOS (both in procedures B and C) allows a correct exposure of the amino groups of the propylamino chain of APTES: in fact, the presence of the sharp peak centred at approximately 1640 cm 21 ( peak number 3) and the two peaks at higher wavelength (approx.…”

Enhancement of the Regenerative Potential of Anorganic Bovine Bone Graft Utilizing a Polyglutamate-Modified BMP2 Peptide with Improved Binding to Calcium-Containing Materials

“…Alternatively, osteoinductive molecules have been covalently linked to, or embedded within, synthetic biomaterials, including calcium phosphates, hydrogels, and others. [34][35][36][37][38] As an additional approach, bioactive molecules can be anchored onto calcium-containing substrates through the use of negatively charged domains that bind to positively charged calcium ions. Examples of such domains include bisphosphonates [39][40][41][42] as well as sequences comprised of negatively charged amino acids, including glutamate, aspartate, or the noncanonical amino acids, gcarboxyglutamate and phosphoserine.…”

Elaboration de biocéramiques phosphocalciques

“…Cette dernière approche est la plus complexeà mettre en oeuvre car elle nécessite le greffage de molécules organiques intermédiaires entre la céramique et la molécule active. Elle est envisagée pour conférer aux biocéramiques des propriétés d'ostéoinduction par le greffage covalentà leur surface de peptides dont le rôle sur le processus de formation osseuse est connu [11]. Notre approche consisteàétablir des liaisons préférentielles de type Si-O-Si entre deséthoxysilanes et une apatite silicatée pour contrôler le taux de greffageà la surface de la biocéramique.…”