The effect of PDRN(Polydeoxyribonuceotide, Placentex®) on Rat Skin Flap Survival

Abstract

Polydeoxyribonuceotide (PDRN) has multiple vascular actions such as angiogenesis and production of a vascular endothelial growth factor (VEGF) through the adenosine A2 receptor stimulation. We applied PDRN on the ischemic flap of rat back and investigated its effects on the flap survival by calculating the area of viable flap and blood perfusion. We think that inadequate perfusion, which is the most common cause of distal flap necrosis, may well be overcome through the neovascularization and VEGF production of the PDRN. A total of 20 Sprangue-Dawley rats were divided into two groups: PDRN group and control group. On the distally based flap of 3×9 cm in size, it was subdermally injected with PDRN and Phosphate Buffered Saline (PBS), which were administered 48 hours prior and immediately after flap elevation. The PDRN group was daily maintained with PDRN (8mg/kg) from postoperative 1st day to 10th day, while same dose of saline was injected in the control group. A survival area of a flap and the amount of blood flow were measured using laser doppler flowmetry. On postoperative day 10, the CD31 positively stained vessels and VEGF protein expression were examined using immunohistochemistry. There was a significant increase in the survival area of the flap in the PDRN group. The mean survival rates of flap in PDRN group (79.5±6.3%) are significantly larger than control groups (51.7±6.7%) on postoperative day 10 (p=0.0009). The blood flow measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. The number of CD31 positively stained vessels (6.70±1.88 in samples from control group and 19.40±5.58 in PDRN group, p=0.001) and VEGF protein expression were significantly higher in the PDRN group. Conclusively, we think that administration of PDRN into the ischemic skin flaps increased VEGF expression, number of capillaries, and blood flow to the flap, thereby improving the rat skin flap survival.