Physicochemical properties and cellular toxicity of (poly)aminoalkoxysilanesfunctionalized ZnO quantum dots Abdelhay Aboulaich, Carmen-Mihaela Tilmaciu, Christophe Merlin et al.-Surface modifications of ZnO quantum dots for bio-imaging Y L Wu, C S Lim, S Fu et al.

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Orange wood biomass is an interesting lignocellulosic material, but its lignin has been little explored. As a structural macromolecule present in the plant cell wall, lignin has been used in nanoencapsulation and nanomedicine, standing out as a good drug carrier. In this study, lignin was extracted by soda pulping process and used to produce nanoparticles for curcumin encapsulation and subsequent application in photodynamic therapy (PDT). The nanoparticles were synthesized by the solvent shifting process and characterized with UV–vis, fluorescence, dynamic light scattering (DLS), ζ-potential, and scanning electron microscopy (SEM). The lignin was soluble in organic solvent and presented an extraction yield of 20.6 ± 2%. The Fourier transform infrared (FTIR) spectroscopy and NMR signals showed that the lignin presents hardwood-type characteristics. The lignin nanoparticles were easily obtained and presented average sizes of 284 ± 60, 287 ± 60, and 502 ± 100 nm for pure lignin, 1% curcumin, and 5% curcumin nanoparticles, respectively. They exhibited a negative ζ-potential of about −42 ± 5 mV. The formulations were evaluated for 30 days and remained stable in phosphate-buffered saline (PBS). The curcumin encapsulation yields were high, above 90% in all formulations. Scanning electron microscopy (SEM) images showed that the nanoparticles are spherical and homogeneous. Studies using hepatocarcinoma (HTC) and HepaRG cells showed that the lignin nanoparticles were nontoxic within 4 h of incubation, and for nanoparticles containing 5% curcumin, toxicity was observed upon application of light in PDT experiments.

Plasmonic nanoparticles (NPs) have been extensively investigated as active materials for application in the optoelectronics, photocatalysis, and electrochemistry fields. In particular, doped metal oxides have attracted significant interest because of their optical and electrical properties. In this study, we investigated the influence of aluminum, gallium, and indium on the doping process of zinc oxide (ZnO) NPs. Physicochemical characterization revealed that, upon doping, ZnO NPs exhibited enhanced optoelectronic properties, including absorption in the near-infrared region. Lattice defects, such as vacancies and interstitials in the ZnO NPs crystal lattice, were also introduced by doping, changing the optical properties, and generating emission in the green-yellow, blue-violet, and orange-red band regions. We also investigated the ability of the ZnO NPs to induce cell death in human tumor cell lines and in a healthy cell line in vitro.