Lubrication is the key to efficient function of human tissues and has significant impact on the comfort level. However, the construction of a lubricating nanofibrous membrane has not been reported as yet, especially using a one-step surface modification method. Here, bioinspired by the superlubrication mechanism of articular cartilage, we successfully construct hydration-enhanced lubricating nanofibers via one-step in situ grafting of a copolymer synthesized by dopamine methacrylamide (DMA) and 2-methacryloyloxyethyl phosphorylcholine (MPC) onto electrospun polycaprolactone (PCL) nanofibers. The zwitterionic MPC structure provides the nanofiber surface with hydration lubrication behavior. The coefficient of friction (COF) of the lubricating nanofibrous membrane decreases significantly and is approximately 65% less than that of pure PCL nanofibers, which are easily worn out under friction regardless of hydration. The lubricating nanofibers, however, show favorable wear-resistance performance. Besides, they possess a strong antiadhesion ability of fibroblasts compared with pure PCL nanofibers. The cell density decreases approximately 9-fold, and the cell area decreases approximately 12 times on day 7. Furthermore, the in vivo antitendon adhesion data reveals that the lubricating nanofiber group has a significantly lower adhesion score and a better antitissue adhesion. Altogether, our developed hydration-enhanced lubricating nanofibers show promising applications in the biomedical field such as antiadhesive membranes.
Lithium sulfide (Li 2 S) is a promising cathode for a practical lithium-sulfur battery as it can be coupled with various safe lithium-free anodes. However, the high activation potential (>3.5 V) together with the shuttling of lithium polysulfides (LiPSs) bottleneck its practical uses. We are trying to present a catalysis solution to solve both problems simultaneously, specially with twinborn heterostructure to shoot off the trouble in interfacial contact between two solids, catalyst and Li 2 S. As a typical example, a Co 9 S 8 /Li 2 S heterostructure is reported here as a novel self-catalytic cathode through a co-recrystallization followed by a one-step carbothermic conversion. Co 9 S 8 as the catalyst effectively lowers the Li 2 S activation potential (<2.4 V) due to fully integrated and contacted interfaces and consistently promotes the conversion of LiPSs to suppress the shuttling. The obtained freestanding cathode of Co 9 S 8 /Li 2 S heterostructures encapsulated in three-dimensional graphene shows a high capacity, reaching 92.6% of Li 2 S theoretical capacity, high rate performance (739 mAh g À1 at 2 C), and a low capacity fading (0.039% per cycle at 1 C over 900 cycles). Even under a high Li 2 S loading of 12 mg cm À2 and a low E/S ratio of 5 μL mg Li 2 S À1 , 86% of theoretical capacity can be utilized.Zejian Li and Chong Luo contributed equally to this study.
Fibronectin (FN) is a well-established hallmark of epithelial-to-mesenchymal transition, and may serve as an omnipresent cancer biomarker regardless of the origins of tumor cells. An ssDNA aptamer (ZY-1) with highly selective binding affinity to mesenchymal stromal cells is previously developed, but the binding target of ZY-1 on the cells and the underlying mechanism is yet to be understood. Here, the identification of FN as the target protein of aptamer ZY-1 is reported for the first time and the mechanism of ZY-1 binding to cFN is explored. The data indicate that ZY-1 solely recognizes cellular fibronectin (cFN) rather than plasma fibronectin (pFN). The ZY-1 binding to cFN is explored through computational modeling and the competition of heparin in binding cFN owing to steric hindrance is confirmed. The in vitro assay and noninvasive in vivo fluorescence imaging results validate the specificity of ZY-1 in targeting cFN and sensitivity in detecting tumors. The ZY-1-mediated targeted cancer therapy using a proof-of-concept study with a ZY-1-based complex loaded with doxorubicin (Dox) is further proved. This study would facilitate more comprehensive studies of anti-FN aptamers in the imaging and treatment of tumors and other FN-associated diseases.
In this work, a general model for artificial photosynthesis with capsule-immobilized enzyme was established based on ordinary differential equations, and a solution sequence was developed to get the analytical solution of the model equations. A coenzymes decomposition mechanism was incorporated into the model to improve the prediction ability for dynamic behavior of the reaction process. Then we showed that, based on the proposed model and the solution method, the rate constants for the kinetics of both the photocatalytic reaction and the enzyme reaction and the mass transfer coefficient across the capsule wall can be obtained effectively by using process experimental data. Finally, based on the analysis using the proposed method, we found that the across-wall mass transfer coefficient of the capsule may determine the transitional time needed for the process to get into steady state, and the enzyme reaction may limit the enzyme-photocatalytic reaction processes.
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