The synthesis of gold nanoparticles (Au-NPs), using Pluronic Ⓡ P103 as soft template to design tuned hybrid gold/P103 nanomaterials, is reported here. The effect of the concentration of P103 and the synthesis temperature on the growth, size, and morphology of Au-NPs were studied. The rheological properties of these hybrid nanomaterials at different measured temperatures were studied as well. By increasing the concentration of P103, the micelles progressively grew due to an increase in the number of surface cavities. These cavities came together causing large nucleation centers and developing larger Au-NPs. The synthesis temperature was varied to induce significant dehydration of the P103 micelles. Below the cloud point temperature micelles underwent distinct changes related to spherical-to-polymer-like micelles transitions. Two nanostructures were formed: (1) small Au-NPs arranged on the surface of micelles, which acted as soft templates, and (2) large and independent Au-NPs. Above the cloud point temperature, Au-NPs were related to the shape and size of the P103 micellar aggregates. Rheological measurements showed that viscosity was sensitive to the concentration of P103. Also, it was demonstrated that synthesis temperature had a considerable influence on viscosity of the produced nanomaterials.

In order to generate bactericidal effects in the oral cavity, several alternatives have been studied, including the use of silver nanoparticles but presents problems such as toxicity and low biocompatibility. From human-inspired systems, the antibacterial efficiency of the hydroxyapatite nanoparticles depends strongly on the type of composites and nanoparticles size. Several types of hydroxyapatite nanoparticles and their derivatives have received much attention for their antibacterial potential effect, including magnesium oxide nanoparticles. The purpose of this research was to produce a biocompatible antimicrobial compound of nanoparticles of hydroxyapatite doped with magnesium oxide to generate antibacterial effects in the oral cavity. The solvothermal method was used to produce hydroxyapatite nanoparticles doped with magnesium oxide. Antibacterial activity of as synthesized nanopowders against cariogenicStreptococcus mutanswas tested by the CLSI disk-diffusion method. As result of this research, hydroxyapatite doped with magnesium nanoparticles (nHAMg) were successfully synthetized by the solvothermal method where in structural characterization indicates magnesium substitution and FTIR analysis gives a broader spectrum of the nHAMg when compared to pure nHA and crystallite size of nHA decreased. Furthermore, results of antibacterial assays showed that nHAMg allow to inhibit the grown ofS. mutansby showing a halo of inhibition around the discs. Moreover, this antibacterial activity is enhanced by the addition of silver ion in an amount below to known toxic concentration, showing a synergetic effect that can further potentiate even more these HA nanoparticles. This work demonstrates that solvothermal method is a promising synthesis way for producing antibacterial hydroxyapatites nanoparticles for biomedical applications such as oral tissue regeneration.