The effects of demineralized bone matrix proteins and osteogenic protein-1 on bone cells isolated in culture.

摘要

With the growing number of bone-related traumas and the limitations of traditional bone repair, alternative methods of bone management must be investigated. Demineralized bone matrix protein (DBX) has been used to reconstruct bone. DBX, a type of demineralized bone matrix, is a combination of several different proteins including osteogenic protein-1 (OP-1). Osteogenic protein-1 or Bone Morphogenic Protein-7 (BMP-7) was the first BMP approved for clinical use in the United States. Previous studies have shown that proliferation of osteoblasts (bone forming cells) was stimulated by OP-1. However, the effects of DBM and OP-1 at the cellular level have not been clearly defined. MG-63 osteosarcoma cells were utilized as a model and subsequently plated onto 24 well tissue culture plates at a density of 1x 10(5) ml/well. Cells were exposed to different concentrations of DBX demineralized bone matrix and OP-1 for periods of 24, 48, and 72 hours and compared with untreated controls. After each incubation period,cell morphology, cell damage, cell number, and protein concentrations were determined. Results indicate a significant increase in cell number at 72 hours in cells treated with 30% (5.66 x 10(5)) and 100% (6.3 x 10(5)) DBX treated groups when compared with the control (1.4 x 10(5)). OP-1 results do not indicate a significant increase in cell number at the 24 and 48 hour treatment phases when compared with the control (p > 0.05), however, results do show a statistically significant difference (approximately twofold, p < 0.05) between the control cells (1.9 x 10(4)) and those cells treated with low (3.9 x 10(4)) and high (4.1 x 10(4)) concentrations of OP-1 at the 72 hour time phase. The increases in cell number indicate that both DBX and OP-1 are effective in stimulating cell growth. When comparing the results of the DBX treatments with those of the OP-1 treatments, the cells treated with DBX showed a more substantial increase in bone cell proliferation after treatment than those cells treated with OP-1. This does suggest that DBX provides the most effective treatment for bone cell proliferation. Closer evaluation of the morphology especially the changes occurring at the nuclear level need to be addressed in future studies.