Bipolar Polymeric Protective Layer for Dendrite-Free and Corrosion-Resistant Lithium Metal Anode in Ethylene Carbonate Electrolyte.

The unstable interface between Li metal and ethylene carbonate (EC)-based electrolytes triggers continuous side reactions and uncontrolled dendrite growth, significantly impacting the lifespan of Li metal batteries (LMBs). Herein, a bipolar polymeric protective layer (BPPL) is developed using cyanoethyl (-CH2CH2C≡N) and hydroxyl (-OH) polar groups, aiming to prevent EC-induced corrosion and facilitating rapid, uniform Li+ ion transport. Hydrogen-bonding interactions between -OH and EC facilitates the Li+ desolvation process and effectively traps free EC molecules, thereby eliminating parasitic reactions. Meanwhile, the -CH2CH2C≡N group anchors TFSI- anions through ion-dipole interactions, enhancing Li+ transport and eliminating concentration polarization, ultimately suppressing the growth of Li dendrite. This BPPL enabling Li|Li cell stable cycling over 750 cycles at 10 mA cm-2 for 2 mAh cm-2. The Li|LiNi0.8Mn0.1Co0.1O2 and Li|LiFePO4 full cells display superior electrochemical performance. The BPPL provides a practical strategy to enhanced stability and performance in LMBs application.

Enhancing Interfacial Contact in Solid-State Batteries with a Gradient Composite Solid Electrolyte.

Solid-state batteries promise to meet the challenges of high energy density and high safety for future energy storage. However, poor interfacial contact and complex manufacturing processes limit their practical applications. Herein, a simple strategy is proposed to enhance interfacial contact by introducing a gradient composite polymer solid electrolyte (GCPE), which is prepared by a facile UV-curing polymerization technique. The high-Li6.4 La3 Zr1.4 Ta0.6 O12 (LLZTO)-content side of the electrolyte exhibits high oxidation resistance (5.4 V versus Li+ /Li), making it compatible with a high-voltage cathode material, whereas the LLZTO-deficient side achieves excellent interfacial contact with the Li metal anode, facilitating uniform Li deposition. Benefiting from the elaborate composition and structure of GCPE films, the symmetric Li//Li cell exhibits a low-voltage hysteresis potential of 42 mV and a long cycle life of >1900 h without short-circuiting. The Li//LiFePO4 solid-state batteries deliver a capacity of 161.0 mA h g-1 at 60 °C and 0.1 C (82.4% capacity is retained after 200 cycles). Even at 80 °C, the cell still shows an outstanding capacity of 132.9 mAh g-1 at 0.2 C after 100 cycles. The design principle of gradient electrolytes provides a new path for achieving enhanced interfacial contact in high-performance solid-state batteries.

Studying endothelial cell shedding and orientation using adaptive perfusion-culture in a microfluidic vascular chip.

Most tissue-engineered blood vessels are endothelialized by static cultures in vitro. However, it has not been clear whether endothelial cell-shedding and local damage may occur in an endothelial layer formed by static cultures under the effect of blood flow shear postimplantation. In this study, we report a bionic and cost-effective vascular chip platform, and proved that a static culture of endothelialized tissue-engineered blood vessels had the problem of a large number of endothelial cells falling off under the condition imitating the human arterial blood flow, and we addressed this challenge by regulating the flow field in a vascular chip. Electrospun membranes made of highly oriented or randomly distributed poly(ε-caprolactone) fibers were used as the vascular scaffolds, on which endothelial cells proliferated well and eventually formed dense intima layers. We noted that the monolayers gradually adapted to the artery-like microenvironment through the regulation of chip flow field, which also revealed improved cellular orientations. In conclusion, we have proposed a vascular chip with adaptive flow patterns to gradually accommodate the statically cultured vascular endothelia to the shear environment of arterial flow field and enhanced the orientation of the endothelial cells. This strategy may find numerous potential applications such as screening of vascular engineering biomaterials and maturation parameters, studying of vascular biology and pathology, and construction of vessel-on-a-chip models for drug analysis, among others.

Inhibition of chemokine receptor CXCR2 attenuates postoperative peritoneal adhesion formation.

BACKGROUND: Postoperative peritoneal adhesions remain a problem after general and gynecological surgery. METHODS: Hematoxylin and eosin and Masson's trichrome staining of ischemic buttons were performed 6, 12, 24 hours, and 7 days after button induction. Scanning electron microscopy, ribonucleic acid sequencing, quantitative real-time polymerase chain reaction, immunohistochemical staining, and flow cytometry were used to elucidate the pathophysiology of postoperative peritoneal adhesions. RESULTS: The results showed that thickening of the peritoneum and abscission of mesothelial cells and collagen fibers increased significantly on the surface of the "button" in the control groups at 24 hours postoperatively. Scanning electron microscopy revealed a large number of granulocytes on the button surface in the control group at 24 hours. Ribonucleic acid sequencing and quantitative real-time polymerase chain reaction also revealed that CXCR2 expression was significantly upregulated. In addition, danirixin, a CXCR2 inhibitor, reduced abdominal adhesion in the injured area by inhibiting the infiltration of inflammatory cells and collagen production. Immunohistochemical staining showed decreased expression of CXCR2 in the adhesion area 7 days after surgery in the treatment group. Flow cytometry showed a significantly decreased neutrophil ratio in the treatment group compared with that in the control group 24 hours after the operation. CONCLUSIONS: Inflammation plays an important role in the early stages of postoperative peritoneal adhesion formation, whereas collagen fibers and angiogenesis play important roles in the late stages. The CXCL2-CXCL3-CXCR2 signaling axis is an important link in the mechanism of postoperative peritoneal adhesion formation, and the application of CXCR2 inhibitors can alleviate the formation of postoperative peritoneal adhesions.