Superhydrophobic Surfaces Prepared from Columnar Units by Convenient Electrodeposition with Excellent Mechanical Stability Impact and Corrosion Resistance.

Regular array structures prepared by laser processing and three-dimensional printing have promising applications in building stable superhydrophobic structures. However, the size of the materials processed by these two methods is affected by the size of the processing equipment, which prevents the processing of large-size materials. In this paper, a columnar unit consisting of a spherical structure with similar mechanical stability to the array structure is designed and prepared for metal surface protection. A convenient electrodeposition method was used to deposit a layer of columnar micron-sized copper consisting of spheres on the surface of a 6061 aluminum alloy. Subsequently, modified ZrO2 nanoparticles and polytetrafluoroethylene (PTFE) were sprayed on the surface to form a superhydrophobic surface with synergistic columnar units and ZrO2 (CAZ). The structure was tested and found to have excellent mechanical stability, maintaining the superhydrophobic properties of the surface even after 200 abrasion cycles of 1000-grit sandpaper under a 500 g load. Moreover, the vertical deformation of the CAZ sample under normal pressure was increased by a factor of 4 compared to the original substrate. Importantly, in subsequent corrosion resistance tests, the CAZ samples showed a two-order-of-magnitude improvement in self-corrosion current density and impedance modulus at low frequencies compared to the original substrate. This strategy is an effective method for preparing mechanically stable superhydrophobic structures that are low-cost and large enough to provide long-term protection for metal surfaces. It is particularly suitable for surface protection of instruments and automotive chassis armor.

Rejuvenating Aged Bone Repair through Multihierarchy Reactive Oxygen Species-Regulated Hydrogel.

Aging exacerbates the dysfunction of tissue regeneration at multiple levels and gradually diminishes individual's capacity to withstand stress, damage, and disease. The excessive accumulation of reactive oxygen species (ROS) is considered a hallmark feature of senescent stem cells, which causes oxidative stress, deteriorates the host microenvironment, and eventually becomes a critical obstacle for aged bone defect repair. Till now, the strategies cannot synchronously and thoroughly regulate intracellular and extracellular ROS in senescent cells. Herein, a multihierarchy ROS scavenging system for aged bone regeneration is developed by fabricating an injectable PEGylated poly(glycerol sebacate) (PEGS-NH2 )/poly(γ-glutamic acid) (γ-PGA) hydrogel containing rapamycin-loaded poly(diselenide-carbonate) nanomicelles (PSeR). This PSeR hydrogel exhibits highly sensitive ROS responsiveness to the local aged microenvironment and dynamically releases drug-loaded nanomicelles to scavenge the intracellular ROS accumulated in senescent bone mesenchymal stem cells. The PSeR hydrogel effectively tunes the antioxidant function and delays senescence of bone mesenchymal stem cells by safeguarding DNA replication in an oxidative environment, thereby promoting the self-renewal ability and enhancing the osteogenic capacity for aged bone repair in vitro and in vivo. Thus, this multihierarchy ROS-regulated hydrogel provides a new strategy for treating degenerative diseases.

Opportunities and challenges in green stormwater infrastructure (GSI): A comprehensive and bibliometric review of ecosystem services from 2000 to 2021.

The great challenges induced by global climate change coupled with rapid urbanization underline the growing urgency for a change in stormwater management with a novel integrated approach. This study conducted a comprehensive review on state-of-the-art knowledge in the research field of green storm infrastructure (GSI) using bibliometric analysis. A corpus of 3988 GSI-related publications (2000-2021) extracted from the Web of Science database was used to evaluate the scientific output in GSI research through the "Bibliometrix" R package and "CiteSpace". Ever since 2010, the number of publications per year exhibited an exponential increase, with the annual publication growth rate of 28.61%. Notably, the United States (23.55%) and China (19.58%) contributed most in GSI publications. "Water" (306) was identified as the most relevant journal in GIS research field, followed by "Sustainability" (252) and "Science of the Total Environment" (200). Cluster analysis unveiled the predominant research themes, i.e., "Conceptual development of GSI" (69.25%), "Adaptation of GSI" (46.89%), and "Performance evaluation of GSI practices" (18.28%). Research foci have generally shifted from conventional engineering-based frameworks (e.g., reduce stormwater runoff and enhance water quality) to ecological-based multi-elements (e.g., preserve natural resources, augment urban biodiversity and optimize land-use patterns). This systematic review concludes trends, challenges and future research prospects of GSI, and aims to provide reference and guidance for decision-makers on the development of a more dynamic, resilient, and robust integrated GSI approach for sustainable urban stormwater management.

ROS-Responsive Selenium-Containing Carriers for Coencapsulation of Photosensitizer and Hypoxia-Activated Prodrug and Their Cellular Behaviors.

The integration of hypoxia-activated chemotherapy with photodynamic therapy (PDT) has newly become a potent strategy for tumor treatment. Herein, a reactive oxygen species (ROS)-responsive drug carriers (PS@AQ4N/mPEG-b-PSe NPs) are fabricated based on the amphiphilic selenium-containing methoxy poly(ethylene glycol)-polycarbonate (mPEG-b-PSe), the hydrophobic photosensitizer (PS), and hypoxia-activated prodrug Banoxantrone (AQ4N). The obtained nanoparticles are spherical with an average diameter of 100 nm as characterized by transmission electron microscope (TEM) and dynamic laser scattering (DLS) respectively. The encapsulation efficiency of the PS and AQ4N reaches 92.83% and 51.04% at different conditions, respectively, by UV-vis spectrophotometer. It is found that the drug release is accelerated due to the good ROS responsiveness of mPEG-b-PSe and the cumulative release of AQ4N is up to 89% within 30 h. The cell test demonstrates that the nanoparticles dissociate when triggered by the ROS stimuli in the cancer cells, thus the PS is exposed to more oxygen and the ROS generation efficiency is enhanced accordingly. The consumption of oxygen during PDT leads to the increased tumor hypoxia, and subsequently activates AQ4N into cytotoxic counterpart to inhibit tumor growth. Therefore, the synergistic therapeutic efficacy demonstrates this drug delivery has great potential for antitumor therapy.