TRANSFORMING GROWTH FACTOR-β1 STIMULATES BONE ONGROWTH TO WEIGHT-LOADED TRICALCIUM PHOSPHATE COATED IMPLANTS

Abstract

Bone growth into cementless prosthetic components is compromised by osteoporosis, by any gap between the implant and the bone, by micromotion, and after the revision of failed prostheses. Recombinant human transforming growth factor-β β β β1 (rhTGF-β1) has recently been shown to be a potent stimulator of bone healing and bone formation in various models in vivo.We have investigated the potential of rhTGF-β1, adsorbed on to weight-loaded tricalcium phosphate (TCP) coated implants, to enhance bone ongrowth and mechanical fixation. We inserted cylindrical grit-blasted titanium alloy implants bilaterally into the weightbearing part of the medial femoral condyles of ten skeletally mature dogs. The implants were mounted on special devices which ensured stable weight-loading during each gait cycle. All implants were initially surrounded by a 0.75 mm gap and were coated with TCP ceramic.Each animal received two implants, one with 0.3 µg rhTGF-β β β β1 adsorbed on the ceramic surface and the other without growth factor. Histological analysis showed that bone ongrowth was significantly increased from 22 ± 5.6% bone-implant contact in the control group to 36 ± 2.9% in the rhTGF-β β β β stimulated group, an increase of 59%. The volume of bone in the gap was increased by 16% in rhTGF-β β β β1-stimulated TCP-coated implants, but this difference was not significant.Mechanical push-out tests showed no difference in fixation of the implant between the two groups. Our study suggests that rhTGF-β β β β1 adsorbed on TCPceramic-coated implants can enhance bone ongrowth.

Research Progress on the Biochemical Modification of Titanium Implant Surface

“…In a dog model study, TGF-β1 was applied to implants to evaluate its influence on bone formation around implants. The results showed that rhTGF-β1 adsorbed on tricalcium phosphate-ceramic-coated implants can enhance bone ongrowth by 59% [38]. Another study confirmed an earlier study in dogs that found a 3-fold increase in the amount of bone ingrowth when the implants were treated with a combination of HA and tricalcium phosphate with TGF-β1 [39].…”

The dimensional accuracy of preparation of femoral cavity in cementless total hip arthroplasty

“…Bone ingrowth into cementless prosthetic components is difficult because of the gap between the prosthesis and the surrounding bone. Examination of the histological sections and corresponding microradiographs clearly demonstrated that direct contact between bone and prosthesis increased the osseous response to the implants (Bobyn et al, 1981;Cook et al, 1988;Dalton et al, 1995;Lind et al, 1996;Sandborn et al, 1988). Dalton et al(1995) evaluated the mechanical and histological response to femoral intramedullary implants with different gaps in dogs.…”

REPAIRING OF RABBIT SKULL DEFECT BY TGF-β1-INCORPORATED COLLAGEN SPONGES OF DIFFERENT THICKNESS

“…One possible way for promoted tissue repairing is to combine suitable growth factors and cytokines with the scaffold matrix. For example, transforming growth factor (TGF) 131 is reported to be effective for bone repairing because it activates the proliferation and differentiation of osteoblast precursor cells [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, even if a high dose of growth factor was injected in an aqueous solution form, it would be difficult to expect the desired biological effect in vivo because of the short half-life of growth factor in the body.…”