OTA 2006 Posters
Scientific Poster #79 Basic Science
Influence of Cell Based VEGF Transfer on Rabbit Osteoblasts in vitro
Claire Li, Student (n); Ru Li, MD (n); James Waddell, MD (n);
Emil Schemitsch, MD (n)
St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
Purpose: Vascular endothelial growth factor (VEGF) is vital for both
angiogenesis and osteogenesis. The aim of this study was to investigate
the effect of cell-based VEGF gene delivery on the proliferation and mineralization
of rabbit osteoblasts in vitro.
Methods: Primary cultured rabbit osteoblasts were divided into four
groups (each n = 6). In Group I, osteoblasts were transfected with pcDNA3.1-VEGF;
in Group II, osteoblasts were transfected with pcDNA-efficiency green fluorescent
protein (EGFP); in Group III, osteoblasts were treated with the supernatant
of fibroblasts that were transfected with VEGF genes; and in Group IV, osteoblasts
were treated with the supernatant of fibroblasts that were transfected with
EGFP. The cells were cultured in ±-EME with 10% FBS, 2% penicillin/streptomycin
with or without 10-7 M dexamethasone and 50g/ml L-ascorbic acid
for 28 days. In the last 4 days, the cells were stimulated to initiate calcium
mineralized nodule formation by adding 10 mM -glycerophosphate. They were
stained by the Von Kossa technique so that the number and the area of the
nodules could be assessed by an imaging analysis system.
Results: The cells transfected by VEGF were indicated by the EGFP-marked
cells under a fluorescent microscope. There was a significant difference
in the total nodule area (mean 18.38 mm SE 3.73 and 5.07 mm SE 0.55, P
<0.05) and count (mean 18.67 SE 3.22 and 2.17 SE 0.40, P <0.001)
between Group I and Group II (ANOVA, SPSS). More unmineralized and smaller
nodules were found in Group III and Group IV. However, the nodules in Group
III covered greater areas with dark brown staining in the cell culture dishes
when compared with Group IV.
Conclusion/Significance: The observations indicate that cell-based
VEGF gene delivery has a positive effect on the proliferation and mineralization
of osteoblasts. The greatest effect is seen with direct transfection of
osteoblast cells. Cell-based VEGF gene therapy may be used to promote fracture
healing.
If noted, the author indicates something of value received.
The codes are identified as a-research or institutional support; b-miscellaneous
funding; c-royalties; d-stock options; e-consultant or employee; n-no conflicts
disclosed, and *disclosure not available at time of printing.
·
The FDA has not cleared this drug and/or medical device for the use
described in this presentation (i.e., the drug or medical device is being
discussed for an "off label" use). · · FDA
information not available at time of printing.