Characterization and evaluation of Bletilla striata polysaccharide/ethanol extract composite multifunctional sponges

Development of a fully functional dressing that can be applied throughout wound healing remains challenging. In this study, Bletilla striata polysaccharide (BSP) and the ethanol extract of B. striata (EEB) were physically blended and vacuum freeze-dried into a new medical dressing with various functions, such as hemostasis, anti-inflammatory, antibacterial and wound healing promotion. The in vivo and in vitro blood coagulation evaluation results showed that the most obvious hemostasis effects coming from the EEB25 sponge was probably due to good water absorption capacity. The drug sensitivity test results showed that the sponges presented a good antibacterial effect originated from the addition of EEB. In addition, the EEB25 sponge showed significant anti-inflammatory effects, as well as excellent biodegradability and biocompatibility. The full-thickness wound experiment illustrated the wound healing rates of EEB25 group on the 8th day and 16th day was 82.76 +/- 2.78% and 95.36 +/- 3.72%, respectively, which showed significant differences (p < 0.05) in comparison to the model group. Histological observations showed that the EEB25 group formed dense collagen fibers, granulation tissue and numerous new blood vessels on the 16th day, with the skin basically cured. Therefore, BSP/EEB multifunctional composite sponge provided a new perspective for the safe application of wound dressings. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).