Abstract
R111
Problem: Electroporation is a gene-delivery technique that has been shown to be effective in transfecting mammalian cells with injected plasmids. We desired to evaluate incisional wound strength after using electroporation to tranfect porcine skin with Transforming Growth Factor-beta 1 (TGF-beta 1), a ubiquitous growth factor involved in wound healing.
Methods: Six Yorkshire swine were marked with 6 standardized linear incision sites along each flank. Each site was exposed to a randomized experimental condition consisting of 1 of 5 control conditions or injection of plasmid DNA expressing TGF-beta 1 followed by electroporation. Incisions through the dermis were created, closed, and allowed to heal for 2 weeks. A template was then used to excise tissue from each site which underwent tensiometry for measurement of breaking strength. Stress and standardized stress across the lesions at their breakpoint were calculated, and data were analyzed using student's paired t tests or ANOVA with replication. Samples were collected for light and electron-microscopic analysis. In a second phase, 3 additional swine underwent a similar regimen with several changes in technique as well as the addition of a strong promoter to the TGF-beta 1 cDNA.
Results: In phase I, a nonstatistically significant trend toward increased wound breaking strength was apparent with respect to the incision sites treated with TGF-beta 1 and electroporation. In phase II, even with the plasmid DNA under the strong promoter, no statistically significant findings were evident with respect to experimental conditions. However, the animals tolerated the regimen well.
Conclusion: Transfection of porcine skin with TGF-beta 1 cDNA by electroporation does not improve incisional wound healing at 2 weeks under the initial conditions used in this study. Technical issues will be discussed along with light and electron-microscopic findings.
Significance: Further research is needed to elucidate appropriate techniques of electroporation and biological assessment of growth factors involved in wound healing.
Support: None reported.