N-Acetyl-l-cysteine-Derived Carbonized Polymer Dots with ROS Scavenging via Keap1-Nrf2 Pathway Regulate Alveolar Bone Homeostasis in Periodontitis

Periodontitis is a type of chronic inflammatory oral disease characterized by the destruction of periodontal connective tissue and progressive alveolar bone resorption. As oxidative stress is the key cause of periodontitis in the early periodontal microenvironment, antioxidative therapy has been considered a viable treatment for periodontitis. However, more stable and effective reactive oxygen species (ROS)-scavenging nanomedicines are still highly needed due to the instability of traditional antioxidants. Herein, a new type of N-acetyl-l-cysteine (NAC)-derived red fluorescent carbonized polymer dots (CPDs) has been synthesized with excellent biocompatibility, which can serve as an extracellular antioxidant to scavenge ROS effectively. Moreover, NAC-CPDs can promote osteogenic differentiation in human periodontal ligament cells (hPDLCs) under H2 O2 stimulation. In addition, NAC-CPDs are capable of targeted accumulation in alveolar bone in vivo, reducing the level of alveolar bone resorption in periodontitis mice, as well as performing fluorescence imaging in vitro and in vivo. In terms of mechanism, NAC-CPDs may regulate redox homeostasis and promote bone formation in the periodontitis microenvironment by modulating the kelch-like ECH-associated protein l (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. This study provides a new strategy for the application of CPDs theranostic nanoplatform for periodontitis.

Ag3PO4-anchored La2Ti2O7 nanorod as a Z-Scheme heterostructure composite with boosted photogenerated carrier separation and enhanced photocatalytic performance under natural sunlight

Developing wide spectra-responsive photocatalysts has attracted considerable attention in the photocatalytic technology to achieve excellent catalytic activity. Ag₃PO₄, with strong response to light spectra shorter than 530 nm, shows extremely outstanding photocatalytic oxidation ability. Unfortunately, the photocorrosion of Ag₃PO₄ is still the biggest obstacle to its application. Herein, the La₂Ti₂O₇ nanorod was used to anchor Ag₃PO₄ nanoparticles in this study, and a novel Z-Scheme La₂Ti₂O₇/Ag₃PO₄ heterostructure composite was constructed. Remarkably, the composite showed strong responsive to most of the spectra in natural sunlight. The Ag⁰ formed in-situ acted as the recombination center of photogenerated carriers, which promoted their efficient separation and contributed to the improved photocatalytic performance of the heterostructure. When the mass ratio of Ag₃PO₄ in the La₂Ti₂O₇/Ag₃PO₄ catalyst was 50%, the degradation rate constant of Rhodamine B (RhB), methyl orange (MO), chloroquine phosphate (CQ), tetracycline (TC), and phenol under natural sunlight irradiation were 0.5923, 0.4463, 0.1399, 0.0493, and 0.0096 min^-1, respectively. Furthermore, the photocorrosion of the composite was greatly inhibited, 76.49% of CQ and 83.96% of RhB were still degraded after four cycles. Besides, the holes and O₂^•- played a significant role in RhB degradation, and it included multiple mechanisms of deethylation, deamination, decarboxylation, and cleavage of ring-structures. Moreover, the treated solution can also show safety to the water receiving environment. Overall, the synthesized Z-Scheme La₂Ti₂O₇/Ag₃PO₄ composite exhibited immense potential for removing various organic pollutants through photocatalytic technology under natural sunlight irradiation.

Hexylresorcinol calix[4]arene-assisted synthesis of ZnO–Au micro–nano materials with enhanced photodegradation performance to degrade harmful organic compounds

HRCA not only acts as a reducing agent, but also plays a role in morphology regulation in the synthesis of ZnO–Au micro–nano materials. Gold particles deposited on the formed ZnO sheets and prevented the sheet-like ZnO from accumulating.

Self-photoreduced Ag0-doped Ag(i)–organic frameworks with efficient visible-light-driven photocatalytic performance

A series of Ag0-doped Ag(i)organic frameworks have been constructed via a facile self-photoreduction strategy and can be applied as efficient photocatalysts for the photocatalytic degradation of methyl orange.

Microwave-assisted synthesis of 3D Bi2MoO6 microspheres with oxygen vacancies for enhanced visible-light photocatalytic activity

Oxygen vacancies (OVs) defects in metal oxide-based photocatalysts play a crucial role in improving the charge carrier separation efficiencies to enhance the photocatalytic performances. In this work, OVs were introduced in 3D Bi₂MoO₆ microspheres through a facile and fast microwave-assisted method via the modulation of tetramethylethylenediamine (TMEDA). EPR, Raman and XPS results demonstrated that large amounts of oxygen vacancies were formed on the surface of BMO microspheres. The photocatalytic properties of the samples were studied by degradation of tetracycline (TC) under visible light. The optimal Bi₂MoO₆ with OVs exhibited optimum photocatalytic activity, and the degradation rate was 7.0 times higher than that of pristine Bi₂MoO₆. This enhancement can be attributed to the 3D structure furnishing more surface active sites and suitable OVs defects favoring the electron-hole separation. Moreover, the defective Bi₂MoO₆ microspheres exhibit high stability because the photocatalytic activity remains almost unchanged after 5 cycles, making them favorable for practical applications. Finally, a possible visible light photocatalysis mechanism for the degradation of TC was tentatively proposed.

CdS nanoparticles grown in situ on oxygen deficiency-rich WO3−x nanosheets: direct Z-scheme heterojunction towards enhancing visible light-driven hydrogen evolution

This work introduces the synthesis of direct Z-scheme CdS/WO_3−x heterojunction photocatalysts and the application of photocatalytic hydrogen evolution.

Wet chemical epitaxial growth of a cactus-like CuFeO2/ZnO heterojunction for improved photocatalysis

A wet chemical epitaxial growth method was employed to fabricate a cactus-like CuFeO₂/ZnO heterojunction for the photocatalytic reduction of benzaldehyde to benzyl alcohol.