Bone formation and bioresorption after implantation of injectable β‐tricalcium phosphate granules–hyaluronate complex in rabbit bone defects

Abstract

The objective of this study was to evaluate the effects of a complex of beta-tricalcium phosphate (beta-TCP) granules and 3.5% hyaluronate (beta-TCP granules-HY complex) compared with a beta-TCP block, in terms of osteoconductivity and biodegradability, to determine whether this complex would be a good candidate for bone void filler. Both materials were implanted into cavities drilled in rabbit femoral condyles. New bone formation and mineral apposition rate were evaluated to analyze osteoconductivity, whereas residual beta-TCP within the defects and tartrate-resistant acid phosphatase (TRAP) cellular activity were studied for beta-TCP resorption. The results show that both the beta-TCP block and the beta-TCP granules-HY complex support bone ingrowth; however, bioresorption was rapid for beta-TCP granules-HY but weak for beta-TCP block. This biodegradation mechanism was considered to be a cell-mediated disintegration by numerous TRAP-positive giant cells. The time lag between the peak value of TRAP-positive giant cell population and that of new bone formation rate suggests that a coupling-like phenomenon could be occurring in the beta-TCP-filled bone defects. In addition, beta-TCP granules-HY complex, which is an injectable, pastelike material, has similar osteoconductive properties to beta-TCP block. Thus, this complex may be useful as a bone filler in clinical application.

Combination with allogenic bone reduces early absorption of .BETA.-tricalcium phosphate (.BETA.-TCP) and enhances the role as a bone regeneration scaffold. Experimental animal study in rat mandibular bone defects

“…Nonetheless, it is important that bone regeneration should accompany the complete absorption of bone substitute material. Chasono et al 8) reported that although the absorption phase of β-TCP granules was totally completed with favorable bone formation, a little remnant of this material could be observed. Further, Gaasbeek et al 1) reported that clinically accepted remnants of β-TCP grafted for an osteotomy gap after high tibial osteotomy were observed from biopsy samples taken more than six months after graft surgery.…”

“…In the present study, the objective was to assess the potential of highly pure, porousβ-TCP granules, OSferion ® (Olympus Biomaterial Corp., Tokyo, Japan), as a scaffold for bone regeneration. One contributing reason for using OSferion ® in this study was that it has been reported that OSferion ® was absorbed with favorable bone formation 8) . Rat mandibular bone defects were thus grafted with OSferion ® with or without allogenic bone, and then the bone formation and absorption rates were evaluated.…”

Cytotoxicity Evaluation and Crystallochemical Analysis of a Novel and Commercially Available Bone Substitute Material

“…In spite of the acknowledged excellent biocompatibility of calcium phosphate ceramicsbased materials [1][2][3]5], the present in vitro study demonstrated some differentiation between chemically similar biomaterials. This may be the reason of the variable clinical performance, but we are not in command of in vivo comparison at the moment.…”

“…They should also resorb and be replaced by newly formed bone [1][2][3]. As many studies have demonstrated, although autografts are the most suitable bone augmentation materials, their limited availability in the oral tissues and their high rate of post surgical morbidity has motivated investigators to utilize other biomaterials in bone regeneration [2][3][4][5][6][7].…”

Repair of segmental bone defects in rabbit tibia promoted by a complex of β-tricalcium phosphate and hepatocyte growth factor

“…Eight weeks after surgery, most of the b-TCP was absorbed and replaced by newly formed bone in the HGF-treated group, whereas b-TCP granules remained in defected regions without HGF. Previous studies indicated that osteoclasts are of major importance in bioresorption of b-TCP [28]. Inhibition of osteoblast formation resulted in reduced b-TCP resorption and bone formation, suggesting a coupling between osteoclast-mediated b-TCP resorption and bone formation [29].…”