Effects of Platelet Supernatants on the Proliferation of Fibroblast and the Wound Healing in the Rabbit

ABSTRACT

The academic, clinical and economic impacts of active approaches to wound care remain undetermined because wound healing occurs through a complex interaction of enzymatic cascades and a cellular module of interdependent components. Platelet-derived wound healing factors, which are released from the platelet alpa-granule, are currently recognized as the main element in wound healing process. This study is aimed at determining whether the human platelet supernatants including various growth factors would improve the wound healing process in vitro and in vivo studies. Platelet supernatants or platelet poor plasma was added to cultured skin fibroblasts and also applied on 8 mm diameter full thickness defects on rabbit ears(4.0-4.5 kg, New Zealand white rabbit). For the determination of cell growth, DNA and collagen synthesis were measured with [3H]-thymidine and [3H]-proline incorporation. For the determination of wound healing, three full thickness defects were made on each rabbit ear and the subjects were divided into 3 groups: control group treated with normal saline(n = 10), platelet supernatants treated group(n = 10), platelet poor plasma treaed group(n = 10). Histologic sections crossing the center of the wound were obtained on the 7th day after the operation. The diameter of wound gap was subsequently measured with a calibrated lens micrometer and the area of new graulation was measured with an image analyzing system. The results were as follows: 1. The platelet supernatants group revealed a significant increment in the DNA and collagen synthesis as compared to that of the platelet poor plasma group(p< 0.05). DNA synthesis and collagen synthesis of cultured fibroblasts in the platelet poor plasma group were significantly increased as compared to the control groups(p< 0.05). 2. The wound diameters were significantly decreased in the platelet supernatants group and new granulation tissues recovered the wound intensively in the platelet supernatants group as well, as compared to the control or platelet poor plasma group(p< 0.05). These results suggested that the platelet supernatants increases proliferation and collagen synthesis of fibroblasts and virtually promotes the wound healing process. As platelet supernatants is safe and cost effective and can be obtained by a simple method, it may be clinically useful as a source of growth factors.