Chronic wounds are a major source of morbidity - causing pain, suffering, and disability. One of the reasons for their abnormal healing appears to be a reduction in the availability of growth factors within chronic wounds. The application of growth factors to wounds has had only limited success in the clinical setting. This lack of efficacy is at least partially due to the short half-lives of these agents and difficulties with their delivery. Gene therapy may allow autologous cells within wounds to express growth factors in an adequate and sustained fashion. This work explores the feasibility of a gene therapy approach for the treatment of skin wounds. A reproducible animal model of impaired wound healing was validated. Evidence of both transcription and translation of an active gene product was demonstrated after intradermal injection of the encoding DNA. Using this approach, injection of several growth factor encoding genes was found to lead to improvements in wound healing when compared to the injection of a non growth factor expressing plasmid vector. Conversely, however, it was also found that both the repeated injections and the high dose of DNA required to achieve this effect had a detrimental effect on healing. To address this problem, several alternative means of improving transfection efficiency were assessed. The use of viral vectors was excluded because of their potential toxicity. Non-viral approaches were concentrated upon. Canonic lipofection and polyfection, effective in vitrv, were found to be of no use in skin tissue. A nuclear localisation signal effective in cell culture was also found to be of no value in vivo. The use of in mo elearoporation was found to hold the most promise for future skin gene therapy applications. Methods to improve in vivo transfection efficiency and duration have the potential to reduce the negative effects caused by high quantities and frequent dosing of DNA and may lead to significantly improved cutaneous wound healing.
|Date of Award||Jul 2003|
- Queen's University Belfast
|Supervisor||Mr D. Carey (Supervisor)|