OBJECTIVETo develop zoledronic acid (ZA)-loaded collagen membranes, and to study its effect on osteoclast and osteoblast so as to investigate whether ZA-loaded membranes can inhibit local bone resorption and promote bone formation.

METHODSZA-loaded double-layer (Bio-Gide(®)) and single-layer (BME-10X(®)) collagen membranes were prepared and divided into eight groups according to the concentrations of ZA in the membrane, namely Group BG0, BG1, BG2, BG3 and BM0, BM1, BM2, BM3 (BG refers to Bio-Gide(®), BM refers to BME-10X(®), 0, 1, 2, 3 refer to the concentrations of ZA, 0, 1 × 10(-4), 1 × 10(-3), 1 × 10(-2) mol/L respectively). Blank control group was set without using collagen membrane. The effects of ZA-loaded membranes on osteoclast and osteoblast were assessed using in vitro cell culture models.

RESULTSIn vitro coculture of ZA-loaded membrane with osteoclast for seven days showed that the percentage of bone resorption area in BG1, BG2, BG3, BM1, BM2, BM3 were 18.80%, 14.75%, 14.28%, 20.51%, 15.77%, 15.12% respectively, which were lower than that in BG0 (31.53%) and BM0 (32.22%, P < 0.05), and the higher ZA loading was, the stronger its inhibition to osteoclast was. In vitro coculture of ZA-loaded membrane with osteoblast for four days indicated that alkaline phosphatase (ALP) activities in BG2 (154.67 U/g), BM2 (154.33 U/g), BG3 (155.33 U/g), BM3 (152.00 U/g) were higher than that in BG0 (129.33 U/g) and BM0 (127.67 U/g, P < 0.05). What's more, results from seven-day coculture showed that proliferation index in BG2 (7.00) was higher than that in BG0 (6.90).

CONCLUSIONSZA-loaded collagen membrane can not only inhibit osteoclastic bone resorption but also improve proliferation of osteoblast.