Targeting polysaccharides such as chitosan, cellulose, alginate and starch for designing hemostatic dressings.

Unfortunately hemorrhage and its complications (e.g. anemia, organ failure, and hypothermia) induced by traumatic injury, surgery, and disorders of bleeding play an all too familiar role in human morbidity and mortality. Therefore, it is difficult to overstate the importance of better understanding the role of polysaccharides in advanced hemostatic dressings (HDs). This review includes consideration of polysaccharide hemostatic dressing mechanism of action, relative efficacy, cost and safety. Polysaccharide-based HDs are widely used in management not only of external and internal bleeding but also of massive hemorrhage. These polysaccharide-based HDs have been shown to be effective in both compressible and non-compressible hemorrhage. Hemostatic dressings are designed with different principles depending on location and extent of injury. This review focuses on polysaccharide HD design and associated hemostatic mechanisms. It addresses current issues, challenges, and future perspectives.

Smart Hydrogel Sensors with Antifreezing, Antifouling Properties for Wound Healing.

Flexible electronic devices with biological therapeutic and sensing properties are one of the current research directions. Here, a multifunctional hydrogel for stress sensing and wound healing was prepared by a simple one-pot method and a solution replacement method. Among them, zwitterionic polymers promote wound healing by promoting the polarization of M2 macrophages, collagen deposition, and blood vessel formation. Glycerin can significantly improve the resilience and frost resistance of the hydrogel, ensuring that a sensor made using the hydrogel can work normally in a cold environment. In addition, zwitterionic polymers are highly biocompatible, providing excellent antibacterial adhesion to aid the wound healing process, and good electrical conductivity enhances sensing sensitivity and stability. Based on these properties, multifunctional hydrogels could detect human vital activities while promoting wound healing, providing new ideas for the fields of diagnosis and wound dressing.

Chitosan for constructing stable polymer-inorganic suspensions and multifunctional membranes for wound healing.

Restricted by the rigid chain structure, chitosan-based materials are very fragile and easy to break up. Herein, a stable and positively charged chitosan/Ti3C2Tx suspension was successfully constructed by adjusting mixing sequence, pH and ratio of chitosan to Ti3C2Tx to prepare a multifunctional membrane (P-CM) with self-standing ability, good flexibility, biocompatibility, excellent photothermal antibacterial properties, and sensitive humidity sensing properties. In the first stage, protonated chitosan acted as sugar coatings was able to be encapsulated on the surface of Ti3C2Tx nanosheets by electrostatic self-assembly, in turn achieving charge reversal of the nanoparticles. In the second stage, chitosan acted as molecular needles to suture the membrane formed by chitosan/Ti3C2Tx particles via vacuum filtration (VAF) with the commercial flexible poly(vinylidene fluoride) (PVDF) membrane. The as-prepared P-CM membrane simultaneously solves the problem of insufficient flexibility of a single component chitosan membrane and the poor bonding between pure Ti3C2Tx membranes and substrate membrane.