Yongyan Yang,Ying Ma,Meiliang Wu,Xueping Wang,Yuan Zhao,Shuangling Zhong,Yan Gao,Xuejun Cui
Self-healing hydrogel is a promising soft material for applications in wound dressings, drug delivery, tissue engineering, biomimetic electronic skin, and wearable electronic devices. However, it is a challenge to fabricate the self-healing hydrogels without external stimuli. Inspired by mussel, the metal-catechol complexes were introduced into the hydrogel systems to prepare the mussel-inspired hydrogels by regulating the gelation kinetics of Fe 3+ crosslinkers with gallic acid (GA) in this research. The amine-functionalized carboxymethyl cellulose (CMC) was grafted with GA and then chelated with Fe 3+ to form a multi-response system. The crosslinking of carboxymethyl cellulose-ethylenediamine-gallic acid (CEG) hydrogel was controlled by adjusting the pH to affect the iron coordination chemistry, which could enhance the self-healing properties and mechanical strength of hydrogels. In addition, the CEG hydrogel exhibited great antibacterial and antioxidant properties. And the CEG hydrogel could strongly adhere to the skin tissue. The adhesion strength of CEG hydrogel on pigskin was 11.44 kPa, which is higher than that of commercial wound dressings (∼5 kPa). Moreover, the thixotropy of the CEG hydrogel was confirmed with rheological test. In summary, it has great potential in the application field of wound dressing.
Broad interest in developing new commercial hemostatic agents has been widely aroused for massive blood loss in terms of hospital surgery and on the battlefield. In this study, we report biomimetic red-blood-cell like (RBC-like) hydrogel microspheres with controllable surface morphology by adjusting the proportion of carboxylated chitosan (CM) and gelatin (G) using Fe 3+ as crosslinking agent. It is worth noting that the microspheres are similar to RBCs in the dry state, with a microporous structure on the surface and a hollow structure inside, and enable restoration to the microsphere shape after absorbing water. The CMG1 microspheres show the best hemostatic effect, as indicated by whole blood coagulation in vitro and rat liver and leg artery damage models in vivo . The microspheres exhibit antibacterial properties against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). In addition, the microspheres have satisfactory degradation performance, hemocompatibility, biocompatibility and histocompatibility. This study indicates that these RBC-like microsphere-based hemostatic powders facilitate a physical barrier in wounds by forming aggregations. In addition, the micropores on the surface of the microspheres make it swell rapidly by absorbing blood, aggregating coagulation factors, activating platelets and ultimately accelerating the coagulation cascade to facilitate hemostasis. In conclusion, CMG1 hydrogel microspheres present potential application in the field of emergency hemostasis.
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