Gene therapy, specifically gene electrotransfer (GET), represents a new non-viral approach for more localized delivery of therapeutic agents to tissues, thereby reducing their systemic toxicity. A plasmid encoding human interleukin-12 (phIL12) is currently in a phase I clinical study in patients with basal cell carcinoma of the head and neck region (Clinicaltrials.gov: NCT05077033). The aim of the thesis was to evaluate the biodistribution of phIL12 plasmid in organs of porcine model after gene electrotransfer at different time points (7, 14 and 28 days), which we did by determining the number of phIL12 plasmid copies by qPCR. We showed that phIL12 plasmid is present in all studied organs/tissues after gene electrotransfer, with the exception of non-draining lymph nodes Lnn. subiliaci. The retention time of the plasmid in most organs (liver, kidney, draining lymph nodes Lnn. cervicales superficiales dorsalis, spleen, ovary, eye and lung) is 7 days. This includes the ovary, which is important in gene therapy, as the introduced genetic material must not be passed on to subsequent generations. In samples of the heart, brain, skin at the site of electrotransfer and skin from a distant site, we detected the plasmid also at the last time point (28 days). Electrotransfer with flat electrodes resulted in a 3-fold higher number of plasmid copies after 7 days with the highest concentration used (2 mg/mL), compared to needle electrodes, but the difference was not statistically significant (p > 0,05).
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