[Hemostatic effect of a novel sheeted fibrin adhesive agent, TO-193, on experimental incision models]

Swelling behavior of calcium ion-crosslinked sodium alginate in an in vitro hemostatic tamponade model

Various types of hemostatic agents are used to manage bleeding in surgery. Many such agents are animal products, which carry the risk of secondary infection. The aim of this study is to develop a novel hemostatic agent from a non-animal source that quickly stops bleeding, is easy to use, and has no risk of infection. In this study, we synthesized calcium ion-crosslinked sodium alginate (Alg-Na/Ca) by partial substitution of Ca ions for Na ions in sodium alginate. We prepared 12 kinds of Alg-Na/Ca powders with different Ca mass ratios, molecular weights, M/G ratios and particle size distributions and measured their swelling ratio and the burst pressure generated. We found that Alg-Na/Ca began to swell immediately after contact with saline, especially Alg-Na/Ca at Ca mass ratios of 74.1-77.0 % showed a high swelling ratio after 2 min and a high burst pressure, over 200 % and 500 mmHg respectively. Also, there is a correlation between the swelling ratio after 2 min and the burst pressure. Our results suggest that, by optimizing the composition conditions, Alg-Na/Ca may be an effective hemostatic agent that could act as a tamponade by absorbing and swelling at a bleeding site to quickly achieve primary hemostasis.

Adhesive and robust multilayered poly(lactic acid) nanosheets for hemostatic dressing in liver injury model

Freestanding biodegradable nanosheets composed of poly(l-lactic acid) (PLLA) have been developed for various biomedical applications. These nanosheets exhibit unique properties such as high adhesiveness and exquisite flexibility; however, they burst easily due to their nanometer thickness. We herein describe a freestanding, multilayered nanosheet composed of PLLA fabricated using a simple combination procedure: (i) multilayering of PLLA and alginate, (ii) gelation of the alginate layers, (iii) fusion-cut sealing, and (iv) elution of the alginate layers. The multilayered nanosheets not only reinforced the bursting strength but also provided a high level of adhesive strength. In fact, they were found to show potential as a hemostatic dressing, and they tended to show reduced tissue adhesion that accompanies liver injury. Therefore, we propose this biomaterial as a candidate for an alternative to conventional therapy in hemorrhage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1747-1757, 2017.