Positively charged conjugated microporous polymers with antibiofouling activity for ultrafast and highly selective uranium extraction from seawater.

Uranium high-efficiency separation from seawater still has some obstacles such as slow sorption rate, poor selectivity and biofouling. Herein, we report a strategy for ultrafast and highly selective uranium extraction from seawater by positively charged conjugated microporous polymers (CMPs). The polymers are synthesized by Sonogashira-Hagihara cross-coupling reaction of 1,3-dibromo-5,5-dimethylhydantoin and 1,3,5-triethynylbenzene, and then modified with oxime and carboxyl via click reaction. The CMPs show an ultrafast sorption (0.46 mg g-1 day-1) for uranium, and possess an outstanding selectivity with a high sorption capacity ratio of U/V (8.4) in real seawater. The study of adsorption process and mechanism indicate that the CMPs skeleton exhibits high affinity for uranium and can accelerate the sorption, and uranium(VI) is adsorbed on the materials by the interaction of oxime/carboxyl ligands and hydantoin. Moreover, the material can be simply loaded onto the filter membrane, and shows remarkable antibiofouling properties against E. coli and S. aureus and excellent uptake capacity for uranium with low concentration in real seawater. This work may provide a promising approach to design adsorbents with fast adsorption rate, high selectivity and antibacterial activity, and expand the thinking over the development of novel and highly efficient adsorbents for uranium extraction from seawater.

Acetylcysteine-decorated Prussian blue nanoparticles for strong photothermal sterilization and focal infection treatment.

The major challenge in bacterial infection in clinical settings is the development of antimicrobial materials in the treatment of drug-resistant bacteria. Herein, we report a new strategy for efficient near-infrared radiation (NIR) photothermal sterilization and focal infection treatment by acetylcysteine-modified Prussian blue nanoparticles (AC-PB). Specifically, AC-PB is fabricated as a multifunctional therapeutic agent via a co-precipitation approach, where PB acts as an effective photothermal agent and AC could prevent the formation of bacteria cluster in biofilms and the bacterial adhesion on tissues to reduce the secretion of mucus and improve the efficacy. AC-PB shows strong synergistic photothermal sterilization ability in a concentration-dependent manner by using 980 nm NIR laser. 50 µg/mL of AC-PB can eliminate up to 74% of Gram-positive Staphylococcus aureus and up to 75% of Gram-negative Escherichia coli, while irradiation of 980 nm is minimally cytotoxic to mammalian cells. The NIR radiation can be efficiently converted into local heat by subcutaneous injection of AC-PB to kill bacteria effectively in vivo to treat a focal infection. The antibacterial mechanism suggests that AC can destroy bacteria-based biofilms, while the photothermal effect driven by NIR may break the lipids on cellular membrane. Thus, this work may provide a promising strategy for highly effective eradication of bacteria in clinics.

A strategy for high radioprotective activity via the assembly of the PprI protein with a ROS-sensitive polymeric carrier.

With the rapid development and wide application of nuclear technology, radiation hazards present an enormous challenge for biological and medical safety. Currently, one of the major challenges in radiation protection is the discovery of more effective and less toxic radioprotectant agents. Herein, we present a strategy for high radioprotective activity via the assembly of the PprI protein with a reactive oxygen species (ROS)-sensitive polymeric carrier. The graft copolymer CS-CP5K-PEG is synthesized via the reaction of PEG-CP5K-NHS and CS, which is used for the assembly of the PprI protein. The assembly complex is less toxic to human cells and more stable to enzymatic cleavage than the PprI protein. The ROS degradability of the CS-CP5K-PEG polymer is confirmed via the SIN-1 mediated cleavage of CP5K peptide linkers through the shift in their GPC chromatogram. The radioprotection activity of the assembly complex is remarkably improved both in HUVECs and C57BL/6 mice compared to that of the PprI protein, showing more beneficial effects than the PprI protein. Thus, this work may provide a new approach for highly effective radioprotection.