Subdermal injection of stromal vascular fraction and plateletrich fibrin; evaluation of effects to the skin components

Aim: Aging process occurs by intrinsically and extrinsically mechanisms. Signs of aging becomes prominent over a period of time. Skin changes are the most significant findings in aging process. (1, 2) In this study, histological changes were evaluated after single injection of normal saline solution (SF), autologous platelet rich fibrin (PRF) and stromal vascular fraction (SVF) on rabbit ear model. The aim of this study is obtaining a proliferative effect that can be used to prevent or decrease the skin changes that occurs by aging process. Material and Method: In this study, 48 ears in 24 New Zealand rabbits (8-12 month age; 2.5-3 kg; female) were used. In every single rabbit, 20-25 ml of inguinal fat was harvested for obtaining SVF and 5 ml of whole blood for obtaining PRF. In the first group 2 ml of saline, in the second group 1 ml of SVF and 1 ml of PRF, in the third group 2 ml of SVF and finally in the fourth group 2 ml of PRF were injected subcutaneously. At the end of first week, first month, second month and third month; tissue samples were collected for histological examination from three rabbit ears in every single group. Results: Statistical evaluation of dermal thickness, microvascular density showed no significant difference but many of the comparisons had a critical statistical difference value (p=0.05). Statistical comparisons of microvascular density between SF group and SVF+PRF and SVF groups had this critical difference value (p=0.05) in the third month. Microvascular density of SVF+PRF and SVF groups were greater than SF group. Comparison between PRF group in the first week and SF group in both the first week and third month showed a critical difference value (p=0.05) too. PRF group had a greater microvascular density than SF group 4 as expected in an early and short lasting effect. Additionally, SVF+PRF and SVF groups had more focal cellular proliferation zones than PRF and SF groups. Conclusion: In this study, expected proliferative and regenerative effects of single injection of SVF and PRF showed no statistically significant histological difference. Despite this, focal cellular and extracellular proliferative effects were evaluated. This study shows us the need for another study that includes repeated injections of SVF and PRF on more animal subjects. Keywords: Stromal vascular fraction, platelet rich fibrin, platelet rich plasma, aging