HA/PEI-coated acridine orange-loaded gold-core silica shell nanorods for cancer-targeted photothermal and chemotherapy

Aims: To develop a tumor-targeted chemo-photothermal nanomedicine through the functionalization of acridine orange (AO)-loaded gold-core mesoporous silica shell (AuMSS) nanorods with polyethylenimine (PEI) and hyaluronic acid (HA). Methods: Functionalization of the AuMSS nanorods was achieved through the chemical linkage of PEI followed by electrostatic adsorption of HA. Results: HA functionalization improved AuMSS' cytocompatibility by decreasing blood hemolysis, and PEI-HA inclusion promoted a controlled and sustained AO release. In vitro assays revealed that HA functionalization increased the internalization of nanoparticles by human negroid cervix epithelioid carcinoma cancer (HeLa) cells, and the combinatorial treatment mediated by AuMSS/PEI/HA_AO nanorods presented an enhanced effect, with >95% of cellular death. Conclusion: AuMSS/PEI/HA_AO formulations can act as tumor-targeted chemo-photothermal nanomedicines for the combinatorial therapy of cervical cancer.

Layer-by-Layer Self-Assembly Composite Coatings for Improved Corrosion and Wear Resistance of Mg Alloy for Biomedical Applications

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

Hydride, chloride, and bromide show similar electronic effects in the Au9(PPh3)83+ nanocluster

Hydride and halide ligands in gold nanoclusters exhibit an unexpected similar electronic relationship, suggesting an underlying chemical linkage between them.

The surface-enhanced Raman scattering detection of N-nitrosodimethylamine and N-nitrosodiethylamine via gold nanorod arrays with a chemical linkage of zwitterionic copolymer

With the PGMA-r-PSBMA surface modification, the Raman scattering cross-sections of NDMA and NDEA molecules were enhanced. Consequently, the Raman signals were detected with good homogeneity, reproducibility, and detection limits.

Synthesis and Catalytic Activity of Activated Carbon Supported Sulfonated Cobalt Phthalocyanine in the Preparation of Dimethyl Disulfide

The Merox process was widely applied in the fine chemical industry to convert mercaptans into disulfides by oxidation with oxygen, including dimethyl disulfide (DMDS). In this paper, a new activated carbon (AC)-supported sulfonated cobalt phthalocyanine (AC-CoPcS) catalyst was prepared through the chemical linkage of ethylenediamine between them. UV−VIS, FT-IR, BET, and XPS were used to characterize the structure of the new catalyst. Then AC-CoPcS was applied to catalyze sodium methylmercaptide (SMM) oxidation for the preparation of DMDS. The effect of process parameters, such as reaction time, catalyst dosage, reaction temperature, and oxygen pressure on SMM conversion per pass (CPPSMM), yield (YieldDMDS), and purity of the DMDS (PurityDMDS) product were investigated to evaluate the catalytic performance of AC-CoPcS. The new supported catalyst exhibits better catalytic performance than the commercial one and can be properly reused four times to obtain CPPSMM and YieldDMDS higher than 90% and 70%. Under the optimum experimental conditions, the CPPSMM and YieldDMDS could reach as high as 98.7% and 86.8%, respectively, and the purity of the DMDS product is as high as 99.8%. This new supported catalyst exhibits good industrial application prospects.

Sulfates of Sorghum vinegar residue waste as potential catalysts

A sealed wet curing design on sulfating Sorghum vinegar residue waste is drilled with sulfo/sulfoalkyl chemicals. Sulfation degrees in the case of reactions with sulfuric acid, sodium sulfite, sulfamic acid, benzenesulfonic acid, p-toluenesulfonic acid and sodium laurilsulfate range from 14.7 to 36.9 mg sulfo per gram waste. The C–O–S formation gives rise to accessional noncrystallinity and mesoporosity of morphology, a character for potential alternatives in catalysis. Waste sulfates are employed as candidates in catalyzing the condensation of α-glycolic acid and urea substitutes for yielding imidazolidine-2,4-dione derivatives. Catalytic and specific activities in terms of derivative productions are 2.6–34.3 (×103 U) and 0.8–5.4 U/mg sulfo, together with the maximal yields of 49.4%–97.6%. Chemical linkage of sulfo/sulfoalkyl groups manifests synergism with intrinsic acidity of waste with respect to catalysis. A rational design of green chemistry is guaranteed by no excess of chemicals and easy recyclability of catalysts.

Antimicrobial glycoconjugate vaccines: an overview of classic and modern approaches for protein modification

Glycoconjugate vaccines obtained by chemical linkage of a carbohydrate antigen to a protein are part of routine vaccinations in many countries.