OTA 2006 Posters
Scientific Poster #78 Basic Science
Can Fibroblast Cells Be Used to Deliver the VEGF Gene to Promote Fracture
Healing?
Ru Li, MD (n); Duncan J. Stewart, MD (n); Herbert vonSchroeder, MD (n);
Emil H. Schemitsch, MD (n);
St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
Purpose: The aim of this study was to determine the feasibility of
using fibroblast cells to deliver the vascular endothelial growth factor
(VEGF) gene locally to promote healing at a rabbit tibia fracture site.
Fibroblast cells are advantageous because they are plentiful and easy to
work with.
Methods: Primary fibroblasts were cultured until 80% confluent and
transfected with pcDNA-VEGF using SuperFect (Qiagen Inc) or labeled with
the viable fluorophore chloromethyl trimethyl rhodamine (CMTMR) for injection.
Using New Zealand White male rabbits, under anesthesia, a 10-mm segmental
bone defect was created after excision of 12 mm of the periosteum in the
middle third of each tibia. The fracture was stabilized with a stainless
steel plate (2.7-mm 9-hole DCP). 14 experimental rabbits were injected with
5.0 x 106 cells transfected with VEGF or cells labeled with CMTMR
in 1 ml saline. The cells were delivered via a gelfoam carrier placed into
the fracture site and by direct injection into the surrounding soft tissues.
The animals were sacrificed at variable times (VEGF group at 7 days (n =
4), 14 days (n = 4) and 21 days (n = 4), and CMTMR group at 24 hours (n
= 2) postsurgery. The specimens were collected and analyzed by ELISA, histology,
immunohistochemistry, and VonKossa staining.
Results: It was demonstrated that the labeled cells were delivered
into and existed at the fracture gap, bone marrow, and muscle surrounding
a segmental defect. Visualized VEGF immunostaining (brown) and VonKossa
staining (dark) was shown in the fracture site. The VEGF protein was detected
in the tissues around the fracture in the VEGF group by ELISA analysis.
Conclusion/Significance: This study has shown the feasibility of
using cell-based gene transfer to express VEGF locally in a segmental defect
model in vivo. These data encourage the further development of approaches
using cell-based VEGF gene transfer with nonviral vectors 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.