Morphological and Ultrastructural Characteristics of Dumontinia tuberosa (Bull.) L.M. Kohn from Ranunculus ficaria L.

Dumontinia tuberosa fungus was observed in different stages of development growing on the roots of Ranunculus ficaria in Cluj-Napoca (Romania), over the course of several years. It is not frequently encountered, therefore, we decided that will be interesting to cultivate it on nutritive medium, and to use the morphological data and the colony’s characteristics to identify the fungus. The identity of the fungus was reaffirmed through a molecular analysis of sclerotium DNA sequences. A new favourable nutritive medium for the growth and development of the fungus is proposed. The morphology and ultrastructure of the fungus were examined by light and electron microscopy, and micrographs of the relevant details are provided. Differences between the ultrastructural characteristics of sclerotium, apothecium stipe, ascospores, asci and paraphyses are presented and discussed. Intercellular spaces were identified in sclerotium and apothecium stipe and the paraphyses. Asci and ascospores were found to be covered by a sticky mucilage. The ultrastructural characteristics of the aforementioned tissues are presented for different developmental stages. Additionally, the main food stores of the fungus, represented by glycogen, lipids and proteins, are located and described along with other characteristic compounds, such as melanin pigment and a glucan extracellular matrix. The present study complements prior information on the worldwide distribution of this rare species in nature and contributes new findings regarding its morphological and ultrastructural characteristics

SPION size dependent effects on normal and cancer cells

Iron oxide nanoparticles have become widely used today in medical applications. In this study, we report a hyperthermia treatment with 10 and 100 nm naked and polyethylene glycol(PEG)-coated Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) to normal and tumor cells in culture. Cells’ responses to nanoparticles were analyzed by cell viability assays (MTT and LDH) and transmission electron microscopy. Results indicate that even if 10 nm SPIONs have good magnetization saturation, the hyperthermia treatment is not effective due to the fact that cells do not endocytose them. 100 nm SPIONs are better engulfed by cells, and their hyperthermia effect is slightly increased. Macavei et al (PDF

Scanning Electron Microscopy and Raman Spectroscopy Characterization of Structural Changes Induced by Thermal Treatment in Innovative Bio-Based Polyamide Nanocomposites

A comprehensive Raman scattering-based characterization of a full bio-based polyamide loaded with graphene nanoplatelets or layered double hydroxides (LDH) was assessed. The potential of the Raman spectroscopy was used to reveal several particularities of the nanocomposite structures induced by thermal treatment. Thus, a complete morpho-structural picture was obtained in combination with scanning electron microscopy (SEM) analysis of the neat polyamide and polyamide nanocomposites exposed at different thermal conditions (room temperature, 80 °C, and 145 °C). The analysis of G, D and 2D Raman peaks and their relative intensity ratio ID/IG, revealed the fact that the presence of graphene in polyamide is suitable for improving the essential physical properties and is also responsible for the decrease in the defects’ occurrence in the graphene layers. The surface of nanocomposites based on full bio-based polyamide, with different 2D fillers (graphenic and non-graphenic structures), was carefully evaluated before and after the thermal treatment by employing SEM and Raman analyses. The two thermal treatments allowed different chain mobility of the polymer (first temperature being over the polymer Tg and second one close to the melting phase in the viscoelastic stage). The spectroscopic and microscopic investigation was used to determine the conformational changes in filler aggregates and polymer surface, respectively

In Vivo Distribution of Poly(ethylene glycol) Functionalized Iron Oxide Nanoclusters: An Ultrastructural Study

The in vivo distribution of 50 nm clusters of polyethylene glycol-conjugated superparamagnetic iron oxide nanoparticles (SPIONs-PEG) was conducted in this study. SPIONs-PEG were synthesized de novo, and their structure and paramagnetic behaviors were analyzed by specific methods (TEM, DLS, XRD, VSM). Wistar rats were treated with 10 mg Fe/kg body weight SPIONs-PEG and their organs and blood were examined at two intervals for short-term (15, 30, 60, 180 min) and long-term (6, 12, 24 h) exposure evaluation. Most exposed organs were investigated through light and transmission electron microscopy, and blood and urine samples were examined through fluorescence spectrophotometry. SPIONs-PEG clusters entered the bloodstream after intraperitoneal and intravenous administrations and ended up in the urine, with the highest clearance at 12 h. The skin and spleen were within normal histological parameters, while the liver, kidney, brain, and lungs showed signs of transient local anoxia or other transient pathological affections. This study shows that once internalized, the synthesized SPIONs-PEG disperse well through the bloodstream with minor to nil induced tissue damage, are biocompatible, have good clearance, and are suited for biomedical applications