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Graphitic carbon nitride (CN) has been widely used in environmental pollution remediation. However, the adsorption of organic compounds on CNs, which has practical significance for the environmental application of CNs, is poorly understood. For the first time, this study systematically investigated the adsorption behaviors and mechanisms of humic substances (HSs), i.e., humic acid (HA) and fulvic acid (FA), on CNs derived from four typical precursors. Intriguingly, CN derived from urea (CN-U) showed a great capacity for HS adsorption due to its porous structure and large surface area, with maximum adsorption amounts of 73.24 and 51.62 mgC/g for HA and FA, respectively. The formation, influencing factors, and relative contributions of multiple interactions to HS adsorption on CNs were thoroughly elucidated. HS adsorption on CNs was mainly mediated by electrostatic interactions, π–π interactions, and H-bonding. The dominance of electrostatic interactions resulted in HS adsorption being highly dependent on pH and ionic strength. HS components with high aromaticity and high molecular weight were preferentially adsorbed due to π–π interactions. These multiple interactions were largely affected by amino groups and tri-s-triazine units of CNs, as well as the moieties of aromatic rings and oxygen-containing groups of HSs.

Iron particle coating can improve the behavior of magnetorheological elastomers (MREs) by inhibiting iron particle rusting; however, such a process can change physical properties of MREs such as oxidation resistance, shear modulus, and stiffness change due to an applied magnetic field. In this study, MRE samples are fabricated with regular and polymerized iron particles. To investigate the possibility and extent of these changes, polymerized particle MRE samples are made using a combination of reversible addition fragmentation chain transfer and click chemistry. Shear test sample MREs with pure elastomer and 50 wt% MRE with and without polymerization are fabricated. To observe the effect of oxidation on shear properties of MREs, pure elastomer and 50 wt% coated and non-coated samples are oxidized using accelerated oxidation procedure. Experimental results show that oxidation significantly reduces the shear modulus of the elastomer matrix. The coating process of iron particles does not significantly change the shear modulus of resulting MREs but reduces the loss of shear modulus due to oxidation.

Native arteries contain a distinctive intima‐media composed of organized elastin and an adventitia containing mature collagen fibrils. In contrast, implanted biodegradable small‐diameter vascular grafts do not present spatially regenerated, organized elastin. The elastin‐containing structures within the intima‐media region encompass the elastic lamellae (EL) and internal elastic lamina (IEL) and are crucial for normal arterial function. Here, the development of a novel electrospun small‐diameter vascular graft that facilitates de novo formation of a structurally appropriate elastin‐containing intima‐media region following implantation is described. The graft comprises a non‐porous microstructure characterized by tropoelastin fibers that are embedded in a PGS matrix. After implantation in mouse abdominal aorta, the graft develops distinct cell and extracellular matrix profiles that approximate the native adventitia and intima‐media by 8 weeks. Within the newly formed intima‐media region there are circumferentially aligned smooth muscle cell layers that alternate with multiple EL similar to that found in the arterial wall. By 8 months, the developed adventitia region contains mature collagen fibrils and the neoartery presents a distinct IEL with thickness comparable to that in mouse abdominal aorta. It is proposed that this new class of material can generate the critically required, organized elastin needed for arterial regeneration.

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As alternative cryoprotectants of conventional organic glycerol, biocompatible synthetic glycopeptides that can assist cryopreservation of red blood cells (RBCs) are proposed in this study. A series of glycopeptides are synthesized via ring-opening polymerization of N-carboxyanhydrides of lysine, aspartic acid, and phenylalanine initiated by poly­(ethylene glycol)-NH2 and followed by chemical tethering carboxylated trehalose to the pendant amino moieties. The synthetic glycopeptides demonstrate distinguished features of low cytotoxicity, low hemolysis, and cell membrane stabilization. The specifically designed glycopeptides enhance cryosurvival recovery of sheep RBCs up to 87.3 ± 0.3% at pH 6.0 and 86.5 ± 0.3% at pH 7.4 together with trehalose during cryopreservation. The synergistic cryopreservation of RBCs is achieved via membrane stabilization of the glycopeptide and ice recrystallization inhibition of trehalose during freezing and thawing. Molecular dynamics simulation indicates that the glycopeptides enhance membrane stabilization at −196 °C by tuning water diffusion. This work provides a potential option of highly efficient and glycerol-free RBC cryopreservation by combination of synthetic glycopeptides and trehalose, which would inspire design and utilization of different mechanisms for the effective cryopreservation of cells or tissues.

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