In the last decades, the advent of nanotechnology has driven the study and application of nanoscale versions of magnetic materials. Among the various nanoparticles under research, iron oxide magnetic nanoparticles (MNP), namely iron oxides magnetite (Fe3O4) and maghemite (γ-Fe2O3), have attracted particular interest due to their superparamagnetism, biocompatibility and biodegradability. MNP are thus ideal platforms to work on a cellular and molecular level in several biomedical applications. In particular, the use of MNP as contrast agents for biomedical imaging through Magnetic Resonance Imaging (MRI) has been explored extensively in the last 30 years, taking advantage of the versatility of MNP functionalization due to the available large surface-to-volume ratio. Polymers, either synthetic or natural, are the most common class of materials employed as coatings for MNP, allowing to customize nanoprobes properties such as size, shape, magnetic relaxation, as well as cell-nanoprobe interactions (for example, specificity towards tissue types, responsiveness to cellular environment features), therapeutic effects or combination with other imaging modalities. While most biopolymers have intrinsic biocompatibility and biodegradability properties and are greener products, synthetic polymers offer engineering versatility and possibility of being tailor-made with specific properties. This review covers the properties of nanoscale iron oxides, production and stabilization methods of such nanoparticles, and their biomedical applications, mainly focusing on the engineering of polymeric-MNP assemblies towards the development of new hybrid magnetic-polymeric MRI nanoprobes.

Hybrid materials have been widely studied for structural applications. Polysaccharide-based fibers, especially cellulosic fibers, have been explored in the last two decades as substitutes of the traditional reinforcements made of glass or carbon fibers due to their mechanical properties. However, their biocompatibility, biodegradability, and chemistry have attracted the researchers and new developments in the field of smart and functional materials arise in diverse applications. This chapter will focus on the biomedical applications of polysaccharide-based smart and functional materials, namely those concerning biosensors and actuators, theranostic systems, and tissue-engineering applications. Special attention will be given to cellulose- and chitin/chitosan-based hybrid materials because these are the two most abundant polysaccharides and probably the most promising for the development of hybrid materials for biomedical applications. Biomimetic strategies for the development of smart and functional hybrid materials will also be highlighted.

The influence of post-deposition thermal annealing on the thermoelectric properties of n-and p-type nanocrystalline hydrogenated silicon thin films, deposited by plasma enhanced chemical vapour deposition, was studied in this work. The Power Factor of p-type films was improved from 7× 10− 5 to 4× 10− 4 W/(mK 2) as the annealing temperature, under vacuum, increased up to 400° C while for n-type films it has a minor influence. Optimized Seebeck coefficient values of 460 μV/K and− 320 μV/K were achieved for p-and n-type films, respectively, with crystalline size in the range of 10 nm, leading to remarkable low thermal conductivity values (< 10 Wm− 1. K− 1) at room temperature.

Transcription is a source of genetic instability that can notably result from the formation of genotoxic DNA:RNA hybrids, or R-loops, between the nascent mRNA and its template. Here we report an unexpected function for introns in counteracting R-loop accumulation in eukaryotic genomes. Deletion of endogenous introns increases R-loop formation, while insertion of an intron into an intronless gene suppresses R-loop accumulation and its deleterious impact on transcription and recombination in yeast. Recruitment of the spliceosome onto the mRNA, but not splicing per se, is shown to be critical to attenuate R-loop formation and transcription-associated genetic instability. Genome-wide analyses in a number of distant species differing in their intron content, including human, further revealed that intron-containing genes and the intron-richest genomes are best protected against R-loop accumulation and subsequent genetic instability. Our results thereby provide a possible rationale for the conservation of introns throughout the eukaryotic lineage.

Biomimetic ligands have emerged to overcome disadvantages inherent in biological ligands. In particular, the Ugi reaction can generate scaffolds where molecular diversity can be introduced, allowing the synthesis and screening of ligand libraries in a high-throughput manner against a variety of biological targets. Two adsorbents bearing Ugi-based synthetic ligands, coined A4C7 and A7C1, were previously developed for the selective recovery of green fluorescent protein (GFP) and RKRKRK-tagged GFP directly from Escherichia coli crude extracts. This work describes, for the first time, the in situ synthesis of Ugi-based ligands on magnetic beads and their application in the magnetic recovery of cognate proteins.