Hydrophobic aerogel-modified hemostatic gauze with thermal management performance

Abstract

Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients, water evaporation and ice crystal growth. To address these challenges, we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze (AWNSA@G) with a layer-by-layer (LBL) structure. Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances. The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat's injured femoral artery model. Moreover, the modified gauze was torn off after hemostasis without rebleeding, approximately 23.8 times of peak peeling force lower than normal gauze. For the LBL structure, consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer, in both hot (70 °C) and cold (−27 °C) environments, exhibited dual-functional thermal management and maintained a stable internal temperature. We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure, the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G. Our work, therefore, shows great hemostasis potential under normal and extreme temperature environments.

Graphical abstract

Schematic showing the strategy of the hemostatic material with thermal management performance. (a) Diagram depicting the fabrication of hydrophobic nano-silica aerogel. HMDSO, hexamethyldisiloxane; HMDS, hexamethyldisilylamine. (b) Illustration of the preparation of hydrophobic nano-silica aerogel-coated gauze. (c) Schematic design of a hemostatic material with thermal management and its application for hemostasis in extreme environments. PCM, phage change material.

Highlights

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  Thermal management performance: an aerogel layer and a phase change material layer protecting thrombin from external stress.

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  Blood-repellent: hydrophobic modified nano-silica aerogel for less blood loss.

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  Unidirectional fluid pumping: the asymmetric wetting nano-silica aerogel coated-gauze (AWNSA@G) avoiding blood seeping out.

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  Fast hemostasis: AWNSA@G promoting platelets adhesion and activating coagulation factor XII.