The effect of recombinant human bone morphogenetic protein-2 on the integration of porous hydroxyapatite implants with bone

Abstract

To determine if recombinant human bone morphogenetic protein-2 (rhBMP-2) can be adsorbed onto porous ceramic hydroxyapatite (HA) and promote the integration of HA to host bone, 54 subperiosteal pockets were created on the skulls of 19 adult Pasteurella-free white rabbits. Fourteen HA implants were saturated with saline and placed in subperiosteal pockets (control), 22 HA implants were saturated with saline and placed into subperiosteal pockets after burring 1-2 mm of calvarium to expose bleeding cancellous bone, and 18 HA implants were saturated with rhBMP-2 and placed into subperiosteal pockets. The animals were sacrificed at 1 month with examination to determine implant mobility. Histology was used to determine the amount of bone growth into the implant. Of the 14 control sites, 10 implants were found to be freely mobile, five demonstrated host bone resorption, and only one exhibited bone growth into the implant. Of the 22 burred sites, eight were freely mobile and 10 demonstrated bone growth into the implant (p = 0.04). Of the 18 rhBMP-2 sites, only two were freely mobile, none demonstrated host bone resorption, and 16 exhibited bone growth into the implant (p = 0.00002). This study supports the use of porous ceramic HA as a biocompatible, osteoconductive implant material for use in craniomaxillofacial augmentation and reconstruction. It also provides evidence that rhBMP-2 enhances osseointegration, thereby fixing the implant in position against the host-bone interface. In the clinical setting, osseous fixation of the implant should aid in preventing displacement, minimizing host bone resorption, and decreasing the incidence of extrusion.

Bone Regenerative Efficacy of Limited-Dose Escherichia Coli–Derived rhBMP-2 With Biphasic Calcium Phosphate Carrier in Rabbit Calvarial Defect Model

“…The results of these studies have shown that carriers of BMP, such as collagen, [3][4][5] hydroxyapatite, 6 allogenic, 7 xenogenic, 8 and alloplastic 9,10 materials, improve the bone-regenerative efficacy of this protein compared with control findings.…”

Bioceramics for Tissue Engineering Applications – A Review

“…The advantage of high porosity in scaffolds has been reported to achieve good cellular distribution, and that it is critical to select the correct pore size [63] . For example, it has been reported that increased HA porosity decreases its malleability and reduces its ability to conform to the irregular surfaces that may be present in host bone [42,[64][65] . This challenge may be overcome by re-engineering a porous HA to deliver bone inductive proteins such as recombinant human bone morphogenic protein 2 (rhBMP 2).…”

Time kinetics of bone defect healing in response to BMP-2 and GDF-5 characterised by in vivo biomechanics

“…It is important to note that the present study does not confirm an endochondral ossification path by means of the measured in vivo mechanical relaxation parameters for the rhBMP-2 treated group, as would have been suggested by some earlier studies (Yasko et al, 1992;Koempel et al, 1998;Einhorn et al, 2003;Edwards et al, 2004;Glatt et al, 2008;Yu et al, 2010). For instance, a study by Yasko et al (1992) that used a rat model similar to ours, demonstrated by weekly histological examination that the healing of rat segmental defects occurs via endochondral ossification.…”