Highly Monodisperse Cu-Sn Alloy Nanoplates for Efficient Nitrophenol Reduction Reaction via Promotion Effect of Tin.

The hexagonal copper-tin alloy (Cu-Sn) nanoplates were synthesized using a high temperature solvent method, the length of six equilateral edges of hexagonal Cu-Sn nanoplates was 23 nm, and the thickness was 13 nm. The obtained hexagonal Cu-Sn nanoplates were highly monodisperse and allowed the formation of nanoarrays arranged with long-range order. The hexagonal Cu-Sn nanoplates exhibited high catalytic activity on catalytic hydrogenation of 4-nitrophenol to 4-aminophenol. Due to the promotion effect of Sn, the apparent rate constant (ka) of hexagonal Cu-Sn nanoplates was three times that of Cu nanoparticles. The density functional theory (DFT) calculations and experimental results demonstrated that Sn could promote the coordination process of -NO2 of 4-nitrophenol with Cu-Sn nanoplates and contribute to activation of 4-nitrophenol. In addition, the hexagonal Cu-Sn nanoplates showed high stability and reusability for the reduction reaction, good adaptability in different pH and the ionic strength, and wide applicability for the degradation of methylene blue, methyl orange, and rhodamine B, even in the industrial wastewater, suggesting that the Cu-Sn nanoplates are promising catalysts in organic industry wastewater treatment.

Effect of injectable calcium alginate-amelogenin hydrogel on macrophage polarization and promotion of jawbone osteogenesis.

Due to persistent inflammation and limited osteogenesis, jawbone defects present a considerable challenge in regenerative medicine. Amelogenin, a major protein constituent of the developing enamel matrix, demonstrates promising capabilities in inducing regeneration of periodontal supporting tissues and exerting immunomodulatory effects. These properties render it a potential therapeutic agent for enhancing jawbone osteogenesis. Nevertheless, its clinical application is hindered by the limitations of monotherapy and its rapid release characteristics, which compromise its efficacy and delivery efficiency. In this context, calcium alginate hydrogel, recognized for its superior physicochemical properties and biocompatibility, emerges as a candidate for developing a synergistic bioengineered drug delivery system. This study describes the synthesis of an injectable calcium amelogenin/calcium alginate hydrogel using calcium alginate loaded with amelogenin. We comprehensively investigated its physical properties, its role in modulating the immunological environment conducive to bone healing, and its osteogenic efficacy in areas of jawbone defects. Our experimental findings indicate that this synthesized composite hydrogel possesses desirable mechanical properties such as injectability, biocompatibility, and biodegradability. Furthermore, it facilitates jawbone formation by regulating the bone-healing microenvironment and directly inducing osteogenesis. This research provides novel insights into the development of bone-tissue regeneration materials, potentially advancing their clinical application.

Posterior C1-C2 screw-rod fixation and autograft fusion for the treatment of os odontoideum with C1-C2 instability.

OBJECTIVE: To report our experience treating os odontoideum with C1-C2 instability via C1-C2 screw-rod fixation and autograft fusion and to explore the clinical efficacy of such a treatment strategy. PATIENTS AND METHODS: We retrospectively reviewed the medical records of patients who were diagnosed with os odontoideum with C1-C2 instability and treated by posterior C1-C2 screw-rod fixation and fusion. Neurological deficits were measured with the Japanese Orthopedic Association (JOA) scoring system and neck pain was assessed using the Visual Analogue Scale (VAS) score. Fusion was determined based on the presence of bridging bone in computed tomography (CT) imaging, whereas stability was determined based on the lack of movement in dynamic radiographs. RESULTS: Thirty-two patients (18 males) were included in the study. The surgery was successfully accomplished in all patients. Thirty (93.8%) patients had confirmed C1-C2 bony fusion in CT images and all patients (100%) were stable in dynamic radiographs. The mean preoperative JOA score was 14.3±1.4 (range 11-16); at the final visit, it increased to 16.2±0.8 (range 14-17) (p<0.001). The mean preoperative VAS score was 3.8±0.7 (range 3-5) and decreased at the final visit to 1.0±0.6 (range 0-2) (p<0.001). CONCLUSION: Our treatment strategy (C1-C2 screw-rod fixation and autograft fusion) can achieve excellent clinical results with minor complications for patients with os odontoideum with C1-C2 instability.