Breathable,antifreezing,mechanically skin-like hydrogel textile wound dressings with dual antibacterial mechanisms

Hydrogels are emerging as the most promising dressings due to their excellent biocompatibility,extracellular matrix mimicking structure,and drug loading ability.However,existing hydrogel dressings exhibit limited breathability,poor environmental adaptability,potential drug resistance,and limited drug options,which extremely restrict their therapeutic effect and working scenarios.Here,the current research introduces the first paradigm of hydrogel textile dressings based on novel gelatin glycerin hydrogel(glyhydrogel)fibers fabricated by the Hofmeister effect based wet spinning.Benefiting from the unique knitted structure,the textile dressing features excellent breathability(1800 times that of the commercially available 3 M dressing)and stretchability(535.51±38.66%).Furthermore,the glyhydrogel textile dressing can also withstand the extreme temperature of-80℃,showing the potential for application in subzero environments.Moreover,the introduction of glycerin endows the textile dressing with remarkable antibacterial property and expands the selection of loaded drugs(e.g.,clindamycin).The prepared glyhydrogel textile dressing shows an excellent infected wound healing effect with a complete rat skin closure within 14 days.All these functions have not been achievable by traditional hydrogel dressings and provide a new approach for the development of hydrogel dressings.

The dual effect of grain size on the strain hardening behaviors of Ni-Co-Cr-Fe high entropy alloys

It has been well documented that grain size plays a critical role in the strain hardening behaviors of metals and alloys.However,the influence of grain size on the strain hardening of high entropy alloys(HEAs)was not fully understood.Here,we report that the grain size not only affects the twinning-induced plasticity(TWIP)effect but also changes the dislocation-based deformation behaviors of face-centeredcubic(fcc)HEAs significantly.The strain hardening and deformation micro-mechanisms of NiCoCrFe and Ni_(2)CoCrFe were investigated using electron channeling contrast(ECCI)analysis.Our results showed that Ni_(2)CoCrFe exhibits a typical three-stage strain hardening behavior and NiCoCrFe shows the fourth stage at high strains due to the TWIP effect.For both NiCoCrFe and Ni_(2)CoCrFe,the increase of grain size leads to a transition of dislocation glide from wavy to planar mode,resulting in a low value and the recovery of strain hardening rate in stage II.The large-grain NiCoCrFe showed a higher strain hardening rate in stage IV due to the promoted deformation twinning.Combining the strain hardening behaviors of the TWIPNiCoCrFe and the mechanically stable Ni_(2)CoCrFe,we showed that the grain size influences the stage II hardening through tuning dislocation glide mode and the stage IV by tailoring deformation twinning activity of the Ni-Co-Cr-Fe HEAs.The grain size just affects stages I and III slightly in the current cases.These findings will also provide some insights into the understanding of strain hardening behaviors in other face-centered-cubic HEAs.