Zhan Xu's research while affiliated with Technical Institute of Physics and Chemistry and other places

Rapid and effective healing of irregular wounds caused by burns, lacerations, and blast injuries remains a persistent challenge in wound care. Hydrogel microsphere dressings that can adaptively fill and adhere to the wounds without external force are desired to treat irregular wounds, providing an external barrier and accelerating healing. Herein, we created multifunctional cellulose‐based surface‐wrinkled microspheres with antioxidant, antibacterial, hygroscopicity, wet‐adhesion and shape‐adaptive capabilities to relieve inflammation, bacteria and excess exudate situations in healing irregular wounds. This dressing rapidly adsorbs exudate and reversibly adheres wetly to the wounds upon being filled, effectively inhibiting bacterial infection and reducing the flooded exudate to accelerate wound healing. Polydopamine (PDA) provides catechol‐based tissue bioadhesion to microspheres through π – π stacking or hydrogen bond interaction, and also establishes a bond bridge with an antimicrobial component (thymol), which not only enables the microspheres to stably adhere to the wound to maintain hygroscopicity, but also improves the release of the introduced antimicrobial component (thymol). In vivo assays, as well as histopathological and immunofluorescence studies have shown that multifunctional cellulose‐based microspheres have excellent pro‐healing abilities and are promising candidates for dehumidification and healing of irregular wound in clinical applications.

Diabetic wounds with hyperglycemic tissue exudates and bacterial infections have become a great challenge that seriously delays the healing of diabetic wounds. Therefore, multifunctional dressings for exudate management of diabetic wound are urgently needed. Herein, a smart dressing with rapid moisture‐drained and non‐adhesive, pH‐responsive, and antibacterial capabilities is proposed for exudate management and wound monitoring. The Janus dressing is assembled with an antioxidant, pH‐sensitive, and hydrophilic cellulose cover and an antibacterial hydrophobic polycaprolactone bottom layer that directly contacts with the wounds, which can unidirectionally and irreversibly drain the wound exudates and weaken the wet adhesion to the wound. In response to the humoral pH variations (5‐9) during the healing process ofdiabetic wounds, the healing process can be in situ monitored according to the distinct pH‐responsive colors of the Janus dressing at different healing stages. In vivo assays and histopathological studies suggest that the Janus dressing has a superior pro‐healing rate, collagen deposition, and angiogenesis than commercial gauze. Notably, such a mulitfunctional dressing provides real‐time wound monitoring simply through a smartphone integrated with Python‐RGB programs, which can significantly alleviate the hyperglycemic exudate‐flooded environment as an alternative strategy for diabetic wound treatment.

First-aid hemostatic agents for acute bleeding can save lives in emergency situations. However, rapid hemostasis remains challenging when uncontrolled hemorrhage occurs on lethal noncompressible and irregular wounds. Herein, cellulose-based cryogel microspheres with deliberately customized micromorphologies for ultrafast water transportation and diffusion, including the shark skin riblet-inspired wrinkled surface with low fluid drag and the hydrophilic nanoporous 3D networks, are developed to deal with the acute noncompressible bleeding within seconds. These cryogel microspheres can rapidly absorb a large amount of blood over 6 times their own weight in 10 s and form a robust barrier to seal a bleeding wound without applying pressure. Remarkably, massive bleeding from a cardiac penetrating hole is effectively stopped using the microspheres within 20 s and no blood leakage is observed after 30 min. Additionally, these microspheres could be readily removed without rebleeding and capillary thrombus, which is highly favorable to rapid hemostasis in emergency rescue.