Search

Universal protein coatings have recently gained wide interest in medical applications due to their biocompatibility and ease of fabrication. However, the challenge persists in protein activity preservation, significantly complicating the functional design of these coatings. Herein, an active dual‐protein surface engineering strategy assisted by a facile stepwise protein–protein interactions assembly (SPPIA) method for catheters to reduce clot formation and infection is proposed. This strategy is realized first by the partial oxidation of bovine serum albumin (BSA) and lysozyme (LZM) for creating stable nucleation platforms via hydrophobic interaction, followed by the assembly of nonoxidized BSA (pI, the isoelectric point, ≈4.7) and LZM (pI ≈11) through electrostatic interaction owing to their opposite charge under neutral conditions. The SPPIA method effectively preserves the conformation and functionality of both BSA and LZM, thus endowing the resultant coating with potent antithrombotic and bactericidal properties. Furthermore, the stable nucleation platform ensures the adhesion and durability of the coating, resisting thrombosis and bacterial proliferation even after 15 days of PBS immersion. Overall, the SPPIA approach not only provides a new strategy for the fabrication of active protein coatings but also shows promise for the surface engineering technology of catheters. [ABSTRACT FROM AUTHOR]

Hemostatic materials facilitate rapid hemostasis and significantly mitigate the potential of fatal hemorrhage in civilian and military traumas. However, most existing hemostatic materials are limited in material‐dependent forms and fail to integrate multifunctionality, thus constraining their versatility for differing settings and wound healing capacity. Herein, a facile, versatile armor strategy is proposed to endow various biomaterials with rapid hemostasis, infection prevention, and tissue healing capabilities. The armor is fabricated on the surface of substrates first through chemical cross‐linking of adhesive catechol (phenol) and collagen (polyamine) inspired by insect sclerotization, followed by zinc ions (Zn2+) chelation based on mussel‐inspired metal‐phenol coordination chemistry, referred to "metal‐phenol‐polyamine system". This armor facilitates clot formation by promoting platelet aggregation and activating both intrinsic and extrinsic coagulation pathways. Moreover, the integrated Zn2+ endows the armor with potent antibacterial properties against both Gram‐positive and Gram‐negative bacteria. Consequently, this strategy armors a hemostatic sponge that effectively controls bleeding in rabbit hemorrhage models and successfully facilitates the complete healing of epidermal traumas in rats within 14 days. This metal‐phenol‐polyamine system‐assisted armor provides a potential and universal strategy for efficient hemostasis and wound healing. [ABSTRACT FROM AUTHOR]

Braided neurovascular flow diverters (FDs) have revolutionized the treatment of aneurysms. However, dual antiplatelet therapy is mandatory for patients with FDs, which increases the risk of adverse side effects like bleeding complications. Surface modification would be of critical relevance to improve the biocompatibility and therefore clinical performance of FDs. Herein, a titanium dioxide (TiO2) covalently immobilized citric acid (CA) nanohybrid coating is fabricated on nitinol (NiTi) braided FDs by liquid phase deposition and dip‐coating, to inhibit thrombosis and promote re‐endothelialization. The CA molecules are covalently bound onto the pre‐deposited TiO2 nanoparticulate coating. The coating has a unique homogenously nanostructured morphology as well as super‐hydrophilicity. Both in vitro and in vivo results verify that the coated samples inhibit platelets and fibrinogen adhesion, delay coagulation time, and concomitantly promote re‐endothelialization. Such appealing properties are ascribed to the nature of CA and TiO2 per se as well as the nanostructured morphology. The present strategy may not only provide a new avenue to surface‐modify braided neurovascular FDs but also shed light on advanced nanohybrid materials for biomedical applications among others. [ABSTRACT FROM AUTHOR]

Biodegradable Zn‐based metals have recently gained great attention for orthopedic implant applications, due to their attractive attributes in biodegradability, mechanics, and bio‐functionalities. However, Zn‐based metals suffer from excessive Zn2+ release leading to bio‐incompatibility and insufficient osteogenic properties. Herein, bioactive molecules incorporated zinc phosphate (ZnP) of metal–organic/inorganic hybrid coatings are constructed on Zn surfaces by dip‐coating, targeting a decrease in Zn2+ release rate and an improvement in biocompatible and osteogenic properties. The bioactive molecules, cysteine, phenylalanine, and bovine serum albumin, are incorporated into inorganic ZnP using a metal–organic/inorganic coordination strategy. As a result, these hybrid coatings are compact, and present different micro/nanostructured surface morphology. The electrochemical and long‐term static immersion results show that the hybrid coatings decrease the corrosion rate of Zn, reduce the Zn2+ ion release rate, and promote hydroxyapatite deposition. In addition, they promote the proliferation and adhesion of preosteoblast MC3T3‐E1 and rat bone marrow mesenchymal stem cells, and up‐regulate the expression of osteogenesis‐related genes. Such appealing properties can be attributed to the characteristic micro/nanostructured surface morphologies and the presence of the bioactive components. These metal–organic/inorganic hybrid coatings provide a novel avenue to modify the surface of Zn‐based metals for orthopedic implant applications. [ABSTRACT FROM AUTHOR]

Abstract: Soil depth reflects the quantity and ecosystem service functions of soil resources. However, there is no universal standard to measure soil depth at present, and digital soil mapping approaches for predicting soil depth at the regional scale remain immature. Using observation of soil profile morphology, we compared the soil depth nomenclatures from the World Reference Base for Soil Resources, Chinese Soil Taxonomy, and Soil Taxonomy. For this study, shallow soils were defined as those with an effective soil depth < 100 cm. Based on legacy data and field soil survey, the spatial distribution of shallow soils in Xinjiang, China, and the main controlling environmental factors were explored. Results showed that shallow soils in Xinjiang are mainly distributed in high altitude regions such as the Tian Mountains. At the regional scale, significant correlations were observed between soil depth and climate factors, as well as between soil depth and vegetation fractional coverage. Contrary to previous conclusions at small spatial scales, terrain attributes could not explain soil depth variation at the regional scale. This study addressed knowledge gaps on soil depth prediction at regional scales while elucidating climate‐vegetation‐soil coevolution. [ABSTRACT FROM AUTHOR]