We assessed at multiple length scales (nanometers to millimeters) the nanocoatings of silver nanoparticles (AgNPs) on model SiO2/Si substrates. The coatings from biogenic AgNPs (from yeasts Rhodotorula glutinis and Rhodotorula mucilaginosa) were compared to those formed from "synthetic" AgNPs capped with citrate and sodium dodecyl sulfate (SDS). With computational analysis of large-field (LF) X-ray images of the whole substrates (5 × 5 mm), we were able to assess the coatings homogeneity, relative amount of AgNPs, and their distribution as agglomerates. Surprisingly, by analyzing more than 100,000 elements (nanoparticles and agglomerates) in each sample, it was observed that the mentioned features have little dependence on the AgNPs morphology and capping agents. All silver nanocoatings resisted when immersed in phosphate-buffered saline medium by forming agglomerates of up to 10 µm2. However, coatings formed with synthetic AgNPs (capped with citrate and SDS) led to a higher antimicrobial efficiency against Staphylococcus aureus.

This work describes the development and characterization of triglyceride-based magnetic nanocomposites for application in magnetic hyperthermia and controlled drug delivery. The magnetic solid lipid nanocomposites (MSLN) constituted by mixtures of trilaurin-tricaprylin and trilaurin-tricaprin have been successfully obtained by emulsification-solvent evaporation method. The developed MSLNs were subjected to an external oscillating magnetic field and showed significant hyperthermia. The samples were exposed to frequencies of 688 and 869 kHz causing, respectively, a temperature increase of 15.5 and 22.7 °C (trilaurin-tricaprylin) and 17.3 and 26.1 °C (trilaurin-tricaprin). Also, in vitro assays in the absence of magnetic field showed that the triglyceride-based formulations were able first to encapsulate and then to sustained release an antitumoural hydrophobic drug. After 72 h of assay trilaurin-tricaprylin and trilaurin-tricaprin released 73 and 55% of their cargo, respectively. In addition, MSLN exhibited low in vitro cytotoxic activity against human neutrophils.