Preclinical cutaneous topical wound treatment with hypoxia- preconditioned autologous blood
Final Report Abstract
Chronic wounds are highly prevalent in patients with diabetes mellitus, in bedridden patients, or occur as a result of circulatory disorders or in connection with other diseases. In Germany alone, a total of around 3-4 million people suffer from a chronic wound every year. Chronic wounds are not only a medical problem, but are also of enormous economic importance due to the high costs of treatment and are a major social problem. In this study, an innovative wound therapy method was used in a porcine animal model after extensive in vitro preliminary work. The effectiveness of hypoxia-induced secretomes (HIS) for reactivation and acceleration of wound healing was tested. HIS is to be obtained from autologous peripheral blood cells (PBCs) that are activated by extracorporeal wound simulation (EWS), i.e. conditioning of PBCs under hypoxia. The use of the body's own resources for wound healing is becoming an increasingly interesting research area in regenerative medicine. In the present study, the effect of topical application of autologous porcine hypoxia preconditioned serum (HPS) on wound healing in a pig wound model was investigated after 6, 10, 14 and 21 days. Porcine HPS showed a 2.8- fold increase in VEGF concentration compared to normal serum (NS), which can be released in a controlled manner in a hydrogel carrier matrix (HPS-H). Porcine HPS also promotes vessel formation with human umbilical endothelial cells (HUVECs) in the tube formation assay. HPS-H was compared with the treatment groups normal serum hydrogel (NS-H), hydrogel (H) and no treatment (NT). On postoperative day 10, wound contraction with HPS-H was significantly increased by 4.6 times, epithelialization by 1.6 times, and total wound closure by 1.8 times. HPS-H showed wound closure as early as day 14, while the wounds of the other groups showed complete healing on day 21. Hyperspectral images showed a higher superficial tissue oxygenation and deep perfusion of HPS-H treated wounds. Immunohistochemical staining of wound biopsies detected higher expression of blood vessels (CD31), lymphatic vessels (LYVE-1), and myofibroblasts (alpha-SMA) in the HPS-H group. These results show that the topical application of HPS is safe and can accelerate dermal wound healing when used autologously in pigs. These preclinical results form a basis for human clinical applicability. Growth factor mixtures obtained by our method could also be used in other areas, such as 1) tissue engineering, 2) to increase transplant volumes (e.g. lipofilling in plastic surgery) or 3) to improve the healing of transplants in damaged tissues (e.g. irradiated tissue; chronic/ischemic wounds; burns).
