Embryotoxicity and visual-motor response of functionalized nanostructured hydroxyapatite-based biomaterials in zebrafish (Danio rerio).

Hydroxyapatite (HA) is a biomaterial widely used in biomedical applications. Many studies have shown that ionic substituents can be incorporated into HA to produce a mineral composition more similar to natural bone tissue with more favorable biological characteristics for application in bone regeneration. However, its potentially toxic effects need to be evaluated before full approval for human use.

Effects of a biomimetic analog-based experimental bonding system on caries-affected and sound dentin.

This study compared the ultrastructure, chemical composition, and proteases activity (PA) of sound (SD) and caries-affected dentin (CAD) in the dentin hybrid layer after using an experimental bonding system containing pyromellitic dianhydride glycerol methacrylate and biomimetic analogs. The bonding system used a three step and a total-etch procedure. Polyacrylic acid (5%) and sodium trimetaphosphate (5%) were added to the primer and monocalcium phosphate monohydrate (9%), beta-tricalcium phosphate (10.

Cellulose nanocrystals from grape pomace and their use for the development of starch-based nanocomposite films.

Nanocomposite films prepared from starch (ST) in the presence of cellulose nanocrystals (CNCs) was performed using grape pomace as raw material. CNCs were obtained by acid hydrolysis and added to filmogenic solutions (1, 2, 5, 10 and 15 g/100 g of ST). Cellulose, CNCs and Nanocomposites were characterized.

Remineralizing potential of dental composites containing silanized silica-hydroxyapatite (Si-HAp) nanoporous particles charged with sodium fluoride (NaF).

Objectives: To synthesize and evaluate the enamel remineralizing potential of dental composites containing silanized silica-hydroxyapatite (Si-HAp) nanoporous particles charged with sodium fluoride (NaF).

Methods: Si-HAp particles were synthesized using a solid-state method. Dental composites were prepared by incorporating 70 wt.

Structural and thermal analyses of zinc and lactose in homeopathic triturated systems.

Background: A series of different experimental approaches was applied in Zincum metallicum (Zinc met.) samples and lactose controls. Experiments were designed to elucidate the effect of zinc trituration and dynamization on physicochemical properties of homeopathic formulations, using lactose as excipient.

Titanium and iron titanium oxide nanoparticles in antennae of the migratory ant Pachycondyla marginata: an alternative magnetic sensor for magnetoreception?

The most accepted hypothesis of magnetoreception for social insects is the ferromagnetic hypothesis which assumes the presence of magnetic material as a sensor coupled to sensitive structures that transmit the geomagnetic field information to the nervous system. As magnetite is the most common magnetic material observed in living beings, it has been suggested as basic constituent of the magnetoreception system. Antennae and head have been pointed as possible magnetosensor organs in social insects as ants, bees and termites.

Biomineralization of calcium carbonate in the cell wall of Lithothamnion crispatum (Hapalidiales, Rhodophyta): correlation between the organic matrix and the mineral phase.

Over the past few decades, progress has been made toward understanding the mechanisms of coralline algae mineralization. However, the relationship between the mineral phase and the organic matrix in coralline algae has not yet been thoroughly examined. The aim of this study was to describe the cell wall ultrastructure of Lithothamnion crispatum, a cosmopolitan rhodolith-forming coralline algal species collected near Salvador (Brazil), and examine the relationship between the organic matrix and the nucleation and growth/shape modulation of calcium carbonate crystals.

Crystallographic orientation and concentric layers in spicules of calcareous sponges.

In this work, the crystallography of calcareous sponges (Porifera) spicules and the organization pattern of the concentric layers present in their inner structure were investigated in 10 species of the subclass Calcaronea and three species of the subclass Calcinea. Polished spicules had specific concentric patterns that varied depending on the plane in which the spicules were sectioned. A 3D model of the concentric layers was created to interpret these patterns and the biomineralization process of the triactine spicules.