Morphostructural and immunohistochemical study for evaluation of nano‐TiO 2 toxicity in Armadillo officinalis Duméril, 1816 (Crustacea, Isopoda, Oniscidea)

Effects of titanium dioxide (TiO2)/activated carbon (AC) nanoparticle on the growth and immunity of the giant freshwater prawn, Macrobrachium rosenbergii: potential toxicological risks to the aquatic crustaceans

Due to their unique physicochemical characteristics, nanomaterials exhibit many excellent properties and functions, leading to their applications in numerous fields. The large-scale production and widespread application of nanomaterials have inevitably resulted in their release into the environment, especially the water environment. Several studies have confirmed that exposure to nanomaterials can be toxic to aquatic organisms. However, few studies have focused on the effects of nanomaterial exposure on growth and immunity in crustaceans. In the present study, juvenile Macrobrachium rosenbergii were exposed to different concentrations of titanium dioxide (TiO₂)/activated carbon (AC) composite nanomaterial (0.1 and 0.5 mg/L) for 45 days. The effects of nanoparticle exposure on digestion and antioxidant-related enzyme activities, as well as the expression of growth and immunity-related genes and signaling pathway, were evaluated. Our results show that in response to low concentration of TiO₂/AC nanoparticle (0.1 mg/L), most of the enzyme activities related to digestion and antioxidation (TPS, LPS, AMS, SOD, and CAT) were diminished. On the contrary, the GSH-Px activity increased under the 0.1 mg/L group of TiO₂/AC nanoparticle concentration. Additionally, the level of digestive and antioxidant enzyme activities we detected was increased when exposed to 0.5 mg/L TiO₂/AC nanoparticle. By comparison to the expression level of growth-related genes in the control group, MSTN, CaBP, E75, Raptor, EcR, and EGF were significantly inhibited at 0.1 and 0.5 mg/L concentrations of TiO₂/AC nanoparticle, whereas the expression level of genes (TLR, JAK, STAT, PPAF, ACP, and AKP) related to immunity was increased when exposed to different concentrations of TiO₂/AC nanoparticle. Compared with the control group (0 mg/L concentration), 5166 DEGs were identified in the TiO₂/AC nanoparticle group, and a large number of DEGs were involved in molting, energy metabolism, stress tolerance, and germ cell development. Moreover, KEGG analysis revealed that many DEGs were assigned into signaling pathways related to metabolic growth and immune stress. These results showed that exposure to TiO₂/AC nanoparticle will result in the changes of enzyme activity and routine mRNA expression, suggesting that TiO₂/AC nanoparticle which existed in aquatic environment might affect the physiology of M. rosenbergii. This study will provide significant information for the evaluation of nanomaterial toxicity on aquatic crustaceans.

TiO2 /SiO2 -NHOC-FA Nanocomposite as a Photosensitizer with Targeting Ability for Photocatalytic Killing MCF-7 Cells in Vitro and its Mechanism Exploration

In the paper, a composite TiO₂ /SiO₂ -NHOC-FA was prepared using the coupling method which is a folic acid-targeted silica-coated titanium dioxide. Their structures were characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), transmission electron microscope (TEM) and zeta potential method. The results showed that the average diameter of the prepared TiO₂ /SiO₂ -NHOC-FA composite is 18 nm, which is spherical. Compared with unmodified TiO₂ , TiO₂ /SiO₂ -NHOC-FA composite had superior water solubility and dispersion, and enhanced its photokilling activity by folic acid-targeted to FR (+) cells. In addition, photocatalytic TiO₂ /SiO₂ -NHOC-FA arrested cell cycle in G2/M phase of MCF-7 cells, resulting in a significant reduction of mitochondrial membrane potential (MMP), and also made the apoptosis rate, ROS components and intracellular calcium concentration increased. It killed the MCF-7 cells through apoptosis pathway. These results for the TiO₂ /SiO₂ -NHOC-FA composite can provide a theoretical basis for the photodynamic development of TiO₂ .

The Luminescence of 1,8-Diazafluoren-9-One/Titanium Dioxide Composite Thin Films for Optical Application

The investigation of innovative label-free α-amino acids detection methods represents a crucial step for the early diagnosis of several diseases. While 1,8-diazafluoren-9-one (DFO) is known in forensic application because of the fluorescent products by reacting with the amino acids present in the papillary exudate, its application for diagnostic purposes has not been fully investigated. The stabilization of DFO over a transparent substrate allows its complexation with biomolecules for the detection of α-amino acids. In this study, DFO was immobilized into a titanium dioxide (TiO₂) matrix for the fluorescence detection of glycine, as a target α-amino acid (a potential marker of the urogenital tract cancers). The DFO/TiO₂ composite was characterized by atomic force microscopy, spectroscopic ellipsometry, fluorescence spectroscopy and fluorescence microscopy. The performed fluorescent studies indicate spectacular formation of aggregates at higher concentration. The measurements performed using various fluorescence and microscopic techniques together with the suitable analysis show that the aggregates are able to emit short-lived fluorescence.

Morphological analysis reveals the presence of Hepatoxylon trichiuri (Holten, 1802) Bosc, 1811 (Cestoda: Sphyriocephalidae) in Lepidopus caudatus (Euphrasen, 1788) (Pisces: Trichiuridae) from the Mediterranean Sea

In this article, we report for the first time the presence of the parasite Hepatoxylon trichiuri in specimens of Lepidopus caudatus from the Mediterranean Sea. A total of four plerocercoids were studied using microscopy techniques for both morphological and histological analysis. RESEARCH HIGHLIGHTS: We report for the first time for the Mediterranean Sea the presence of the parasite Hepatoxylon trichiuri in specimens of the commercial fish species Lepidopus caudatus. The plerocercoids of H. trichiuri not seems cause observable illness in the fish. However, further studies are needed in order to better assess the incidence and prevalence of the parasite in L. caudatus and other fish species of commercial interest.