【Objective】To investigate the osteogenesis property of osteoprogenitor cells in canine maxillary sinus floor mucosa. 【Methods】 Beagle maxillary sinus mucosa was obtained and the histological morphology was observed under microscope. Osteoprogenitor cells were harvested from canine maxillary sinus floor mucosa

then cultured. Cellular surface antigens of CD44

CD146

and CD34 at passage one were determined by flow cytometry. Cells at passage one were cultured in osteogenic inductive medium to investigate the osteogenesis property in vitro. Alkaline phosphatase activity was tested at day 3

7

and 12 after induction

respectively. Cells in the control group were cultured in basal medium. Immunohistochemistry stain of BMP-2 was performed at day 16 after induction

and cells in the control group were cultured in basal medium. The protein expression level of BMP-2 at 0 d

7 d

and 16 d after induction were tested by Western blot analysis. When induction for 28 d

alizarin red staining and Von Kossa staining were used to observe the formation of mineralized nodules. After being cultured in osteogenic inductive medium for 7 days

cells of passage two were composited with Bio-Oss

implanted into the back of nude mouse subcutaneously to observe the bone formation ability in vivo. And Bio-Oss particles were implanted in control group. 【Results】 The canine maxillary sinus floor mucosa was composed of epithelial layer

lamina propria

submucosa and periosteum. The submucosa was rich of capillaries. Flow cytometry detection showed CD44 and CD146 were positive

CD34 was negative. At day 3

7

and 12

alkaline phosphatase activity increased gradually

and that of cells cultured in osteogenic inductive medium was higher than in basal medium. Compared with in basal medium

BMP-2 protein expression enhanced when cells were cultured in osteogenic inductive medium. The protein expression level of BMP-2

which determined by Western blot

was evident and increased step by step at 0 d

7 d

and 16 d after induction. Obvious mineralized nodules formed when cultured in inductive medium for 28 d. Bone formation behavior was observed after implantion of cells and Bio-Oss composite in nude mouse subcutaneously

no bone formation in control group. 【Conclusion】 Just the same as that of humans

canine maxillary sinus floor mucosa contains osteoprogenitor cells

which possess the ability of osteogenesis.