Spatiotemporally dynamic therapy with shape-adaptive drug-gel for the improvement of tissue regeneration with ordered structure

A spatiotemporally dynamic therapy(SDT)is proposed as a powerful therapeutic modality that provides spatially dynamic responses of drug-carriers for adapting to the wound microenvironment.Herein,dynamic chitosan-poly(ethylene glycol)(CP)Schiff-base linkages are employed to perform SDT by directly converting a liquid drug Kangfuxin(KFX)into a gel formation.The obtained KFX-CP drug-gel with shape-adaptive property is used to treat a representative oral mucositis(OM)model in a spatiotemporally dynamic manner.The KFX-CP drug-gel creates an instructive microenvironment to regulate signaling biomolecules and endogenous cells behavior,thereby promoting OM healing by the rule of dynamically adjusting shape to fit the irregular OM regions first,and then provides space for tissue regeneration,over KFX potion control and the general hydrogel group of CP hydrogel and KFX-F127.Most interestingly,the regenerated tissue has ordered structure like healthy tissue.Therefore,the SDT provides a new approach for the design of next generation of wound dressing and tissue engineering materials.

Surface-engineered binder-free PEDOT shielded nickel magnesium selenide nanosheet arrays electrode for ultralong-life flexible quasi-solid-state hybrid supercapacitors

Together with the development of high-performance advanced electronics,flexible supercapacitors(SCs)with tailored nanostructures have great attraction.Electrochemically deposited nanosheet arrays of nickel magnesium selenide(NixMg3-xSe4,NMgS)with high capacitance provide high potentials as a positive electrode in flexible SCs.To further enhance their electrochemical properties and long-term cycling stability,a promising strategy of surface engineering with conducting polymer poly(3,4-ethylenedioxythiophene)(PEDOT)is proposed.The present work proposes the construction of PEDOT shielded NMgS(P@NMgS-2)on a flexible carbon cloth substrate via a hierarchical electrodeposition technique.Benefitting from the synergistic effect,the P@NMgS-2 exhibits an excellent areal capacitance value of 1440 mF cm^(-2)at 4 mA cm^(-2).A novel shape-adaptable polymer gel electrolyte-assisted flexible quasi-solid-state hybrid SC(FQHSC)device constructed with P@NMgS-2 as a positive electrode and activated carbon as a negative electrode demonstrates the maximum power and energy density values of 14.13 mW cm^(-2)and 0.18 mWh cm^(-2),respectively,followed by outstanding cycling stability(∼100%capacitance retention over 50,000 cycles).Furthermore,the FQHSC device successfully powered electronic devices with no serious degradation upon bending and twisting for wearable electronic applications.

Injectable chitosan hydrogels loaded with antioxidant agent as first-aid dressings for second-degree burn wounds

Burn wounds are destructive skin traumas typically of irregular shape and large area. Prone to infection, they require frequent dressing replacement, and painless removal of dressings from burn wounds remains a major challenge. This study focuses on the dynamic characteristics and treatment difficulty of burn wounds. Hydrogel dressings based on glycol chitosan and propionaldehyde-or benzaldehyde-terminated 4-arm poly(ethylene glycol) were designed on the basis of Schiff base cross-linking networks. The hydrogels exhibited shape-adaptability, self-healing and fast-degradation properties, which makes these hydrogels suitable for burn wounds. Salvianolic acid B(SaB)-loaded hydrogel exhibited good antioxidant properties in vitro. In a rat model of deep second-degree burn wounds, the SaB-loaded hydrogel could quickly reduce wound temperature, regulate wound oxidant microenvironment, promote angiogenesis, and accelerate wound healing. Thus, the drug-loaded hydrogel shows significant potential as a first-aid dressing for treatment of burn wounds.

Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment

Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena.However,current hemostats not only present limitation when treating major bleeding,but also have various side effects.Here we report a self-expanding porous composites(CMCP)based on novel carboxymethyl cellulose(CMC)fibers and acetalized polyvinyl alcohol(PVA)for lethal hemorrhage control.The CMC fibers with uniform fibrous structure,high liquid absorption and procoagulant ability,are evenly interspersed inside the composite matrix.The obtained composites possess unique fiber-porous network,excellent absorption capacity,fast liquid-triggered self-expanding ability and robust fatigue resistance,and their physicochemical performance can be fine-tuned through varying the CMC content.In vitro tests show that the porous composite exhibits strong blood clotting ability,high adhesion to blood cells and protein,and the ability to activate platelet and the coagulation system.In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model.Additionally,the CMCP will not fall off from the injury site,and is also easy to surgically remove from the wound cavity after the hemostasis.Importantly,results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes,to accelerate hemostasis while protecting wound tissue and preventing infection.