ABSTRACT
ABSTRACT Introduction: The objectives of this study are to experimentally evaluate the haemostatic effects of two organic substances, a membrane of chitosan and a collagen sponge coated with thrombin and human fibrinogen (TachoSil®), in sealing 7-0 needle stitches holes on the femoral arteries of rats as well as to evaluate local histological reactions. Methods: Twenty-four rats were included, and four holes were made in each common femoral artery. In the control group, haemostasis was achieved only by compression with gauze sponge; and in the two other groups, haemostasis was achieved with application of one of these two substances. Results: Membrane of chitosan and TachoSil® showed a power to reduce the time to achieve haemostasis compared with the control group (P=0.001), and the haemostatic effects of these two substances were comparable. There was lower blood loss in the groups where these two substances were used when compared with the control group, but no difference was found comparing the two substances. Conclusion: The use of these sealants did not promote more adhesion or local histological reactions when compared to the control group. Since chitosan is easy to find in nature, has a positive effect to promote haemostasis, and did not bring considerable local reactions, it might be used as a sealant in cardiovascular surgery.
ABSTRACT
Abstract Tissue engineering suggests different forms to reconstruct tissues and organs. One of the ways is through the use of polymeric biomaterials such as poly(L-lactic acid) (PLLA). PLLA is a recognized material in tissue engineering due to its characteristics as biocompatibility and bioresorbability. In this work PLLA fibrous membranes were produced by a simple technique known as rotary jet spinning. The rotary jet spinning consists of fibrous membranes production, with fibers of scale nano/micrometric, from a polymeric solution through the centrifugal force generated by the equipment. The membranes formed were subjected to preliminary in vitro assays to verify the cytotoxicity of the membranes made in contact with the cells. Direct cytotoxicity assays were performed through the MTT, AlamarBlue® and Live/Dead® tests, with fibroblastic and osteoblastic cells. The results obtained in this study showed that PLLA membranes produced by rotary jet spinning showed promising results in the 24-hours contact period of the cells with the PLLA fibrous membranes. The information presented in this preliminary study provides criteria to be taken in the future procedures that will be performed with the biomaterial produced, aiming at its improvement.