[Effect of recombinant human osteoprotegerin on osteoclasts stimulated by polyethylene particles].
OBJECTIVE
To observe the effect of recombinant human osteoprotegerin (rhOPG) on osteoclasts which were stimulated by polyethylene particles and to investigate the feasibility of applying rhOPG for the prosthetic aseptic looseness.


METHODS
The osteoclasts were isolated from the long bones of 5 New Zealand rabbits born within 24 hours, weighing 80-100 g, male or female, and were plated into the 24-well coverslips (10 mm x 10 mm) and bone slices (8 mm x 8 mm x 50 microm) at the density of 1 x 10(5)/mL. Based on the different concentration and density of rhOPG and polyethylene particles, the plates of culture were divided into 3 groups: the group with polyethylene particles of 1 x 109/mL (polyethylene group), the group co-cultured with polyethylene particles of 1 x 10(9)/mL and rhOPG of 100 ng/mL (polyethylene/rhOPG group) and the control group. The glass cover slips and bone slices were exposed to HE, toluidine blue and tartrate-resistant acid phosphatase (TRAP) staining at 1, 3, 5 and 7 days, and TRAP positive multinucleated cells and bone resorption tips were counted. Scanning electron microscope was used to observe the pits of bone resorption.


RESULTS
The osteoclast was rose-red when exposed to TRAP staining. For the number of the TRAP-positive osteoclasts, the polyethylene group witnessed an obvious increase compared with the control group and the polyethylene/rhOPG group after 5 and 7 days of culture (P < 0.05). And no significant difference between the control group and the polyethylene/rhOPG group was evident (P > 0.05). The pits of bone resorption was blue-purple when exposed to toluidine blue staining. For the number of bone resorption pits in the bone slice, significant difference was evident between the polyethylene group and the control group after 5 and 7 days of culture (P < 0.05), and there was significant different between the polyethylene/rhOPG group and the polyethylene group 1, 3, 5 and 7 days after culture (P < 0.05).


CONCLUSIONS
rhOPG could inhibit the stimulated effect of polyethylene particles on osteoclasts, and might be used to prevent the prosthetic aseptic looseness after artificial joint substitution.
Zhang
Hailong
H
Department of Orthopaedics, the Second Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing, PR China.
Huang
Chaoliang
C
Chen
Shirong
S
D000818:Animals; D002478:Cells, Cultured; D006801:Humans; D007595:Joint Prosthesis; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects*; D053244:Osteoprotegerin / Q000494:pharmacology*; D020959:Polyethylene / Q000009:adverse effects*; D011817:Rabbits; D011994:Recombinant Proteins
D053244:Osteoprotegerin; D011994:Recombinant Proteins; D020959:Polyethylene