Several copper complexes have been assessed as anti-tumor agents against cancer cells. In this work, a copper compound [Cu(H2O){OS(CH3)2}L](NO3)2 incorporating the ligand 4′-phenyl-terpyridine antiproliferative activity against human colorectal, hepatocellular carcinomas and breast adenocarcinoma cell lines was determined, demonstrating high cytotoxicity. The compound is able to induce apoptosis and a slight delay in cancer cell cycle progression, probably by its interaction with DNA and induction of double-strand pDNA cleavage, which is enhanced by oxidative mechanisms. Moreover, proteomic studies indicate that the compound induces alterations in proteins involved in cytoskeleton maintenance, cell cycle progression and apoptosis, corroborating its antiproliferative potential.

The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

Gene knockout studies on Geobacter sulfurreducens (Gs) cells showed that the outer membrane cytochrome OmcF is involved in respiratory pathways leading to the extracellular reduction of Fe(III) citrate and U(VI) oxide. In addition, microarray analysis of OmcF-deficient mutant versus the wild-type strain revealed that many of the genes with decreased transcript level were those whose expression is upregulated in cells grown with a graphite electrode as electron acceptor. This suggests that OmcF also regulates the electron transfer to electrode surfaces and the concomitant electrical current production by Gs in microbial fuel cells. Extracellular electron transfer processes (EET) constitute nowadays the foundations to develop biotechnological applications in biofuel production, bioremediation and bioenergy. Therefore, the structural characterization of OmcF is a fundamental step to understand the mechanisms underlying EET. Here, we report the complete assignment of the heme proton signals together with (1)H, (13)C and (15)N backbone and side chain assignments of the OmcF, excluding the hydrophobic residues of the N-terminal predicted lipid anchor.

Gene knock-out studies on Geobacter sulfurreducens (Gs) cells showed that the periplasmic triheme cytochrome PpcD is involved in respiratory pathways leading to the extracellular reduction of Fe(III) and U(VI) oxides. More recently, it was also shown that the gene encoding for PpcD has higher transcript abundance when Gs cells utilize graphite electrodes as sole electron donors to reduce fumarate. This sets PpcD as the first multiheme cytochrome to be involved in Gs respiratory pathways that bridge the electron transfer between the cytoplasm and cell exterior in both directions. Nowadays, extracellular electron transfer (EET) processes are explored for several biotechnological applications, which include bioremediation, bioenergy and biofuel production. Therefore, the structural characterization of PpcD is a fundamental step to understand the mechanisms underlying EET. However, compared to non-heme proteins, the presence of numerous proton-containing groups in the redox centers presents additional challenges for protein signal assignment and structure calculation. Here, we report the complete assignment of the heme proton signals together with 1H, 13C and 15N backbone and side chain assignments of the reduced form of PpcD.

Adenoviruses are important platforms for vaccine development and vectors for gene therapy, increasing the demand for high titers of purified viral preparations. Monoliths are macroporous supports regarded as ideal for the purification of macromolecular complexes, including viral particles. Although common monoliths are based on synthetic polymers as methacrylates, we explored the potential of biopolymers processed by clean technologies to produce monoliths for adenovirus purification. Such an approach enables the development of disposable and biodegradable matrices for bioprocessing. A total of 20 monoliths were produced from different biopolymers (chitosan, agarose, and dextran), employing two distinct temperatures during the freezing process (−20 °C and −80 °C). The morphological and physical properties of the structures were thoroughly characterized. The monoliths presenting higher robustness and permeability rates were further analyzed for the nonspecific binding of Adenovirus serotype 5 (Ad5) preparations. The matrices presenting lower nonspecific Ad5 binding were further functionalized with quaternary amine anion-exchange ligand glycidyltrimethylammonium chloride hydrochloride by two distinct methods, and their performance toward Ad5 purification was assessed. The monolith composed of chitosan and poly(vinyl) alcohol (50:50) prepared at −80 °C allowed 100% recovery of Ad5 particles bound to the support. This is the first report of the successful purification of adenovirus using monoliths obtained from biopolymers processed by clean technologies.

Chitin, the second most abundant polymer in nature, is a renewable, nontoxic, biodegradable, and antibacterial polysaccharide. This semicrystalline biopolymer exhibits hierarchical structure from nano to micro-scale and is responsible for interesting living tissue properties. Recently, the scientific interest in chitin nanofibrils for applications in biomedical and tissue engineering fields has increased due to their particular capabilities such as matrix reinforcements, bioactivity and morphology similar to natural tissues. This chapter is focused on composite materials reinforced with chitin nanofibrils and their biomedical applications.

The influence of Ag nanoparticles (Ag NPs) on the luminescence of electrospun nonwoven mats made of polyvinylpyrrolidone (PVP) has been studied in this work. The PVP fibers incorporating 2.1–4.3 nm size Ag NPs show a significant photoluminescence (PL) band between 580 and 640 nm under 325 nm laser excitation. The down conversion luminescence emission is present even after several hours of laser excitation, which denotes the durability and stability of fibers to consecutive excitations. As so these one-dimensional photonic fibers made using cheap methods is of great importance for organic optoelectronic applications, fluorescent clothing or counterfeiting labels.

The influence of Ag nanoparticles (Ag NPs) on the luminescence of electrospun nonwoven mats made of polyvinylpyrrolidone (PVP) has been studied in this work. The PVP fibers incorporating 2.1–4.3 nm size Ag NPs show a significant photoluminescence (PL) band between 580 and 640 nm under 325 nm laser excitation. The down conversion luminescence emission is present even after several hours of laser excitation, which denotes the durability and stability of fibers to consecutive excitations. As so these one-dimensional photonic fibers made using cheap methods is of great importance for organic optoelectronic applications, fluorescent clothing or counterfeiting labels.

The eutrophication of surface waters caused by cyanobacteria is a worldwide problem, leading to expensive
water treatment costs [1]. In addition, the production of microcystins by these microalgae may cause many
health problems to humans and animals (e.g. liver cancer) and even death [2]. Therefore, a variety of
methods have been developed to control cyanobacteria blooms, including physical and chemical treatments.
However, they have negative impacts on other species of (micro) algae and on other aquatic biota. As a
consequence, ultrasonic algae treatment has been proposed as a clean approach to controlling the blooms of
some algae species and microcystins degradation [3]. Still, the specific effects of ultra-sonication on
cyanobacteria are not well known. The present work aimed to study the effects of ultra-sonication on the
cyanobacteria structure under different ultrasound conditions (changing frequency and power) by using
conventional histology and electron microscopy methods.
Microcystis spp. were harvested in a lake from Azores (Portugal) and stored in the cool and dark until
transported to the laboratory. Cyanobacteria were cultured in liquid BG-11 axenic medium at 22ºC in an
incubator chamber, under continuous illumination (fluorescent cold white light).
Samples were collected and suspensions of cells (1ml each) were subjected to ultrasonic irradiation using
diverse ultrasonic equipment (UP100H; UP200S, sonoreactor UTR 200 and ultrasonic bath) and testing
different exposure times. All the experimental algal suspensions were exposed for 5 min to ultrasonication
(on ice for periods of 10s to avoid heating). After ultrasonication cyanobacteria growth was assessed for a
period of 14 days and structural changes in cells were evaluated by light (LM) and scanning electron
microscopy (SEM) examination. The results show growth inhibition of the cyanobacteria according to
intensity and power used in each ultrasonic device. The use of the most powerful devices (sonoreactor and
UP200S) resulted in a massive disrupting of cell walls with consequent cell death (Fig. 1e,f). Similar results
were obtained by Ahan et al. [1] and Nakano et al. [4] and showing cell wall disruption. However, even
after exposure to the most powerful instrumentation it was possible to detect some viable cells and after 14
days colonies were already visible. The results from light and electron microscopy showed noticeable
changes at the structural level such as disruption of cell gas vacuoles (arrowhead), colony disaggregation and
damage of cell walls of cells (Fig. 1c-f).
As a consequence, the use of ultrasounds to improve water quality from eutrophic waters must be considered
with careful in terms of efficiency and other complementary methods should be considered to assure good
water quality criteria. In addition, the effects of ultrasonication in other aquatic organisms require further
studies before using this technology to control algae blooms.

Nanotheranostics takes advantage of nanotechnology-based systems in order to diagnose and treat a specific disease. This approach is particularly relevant for personalized medicine, allowing the detection of a disease at an early stage, to direct a suitable therapy toward the target tissue based on the molecular profile of the altered phenotype, subsequently facilitating disease monitoring and following treatment. A tailored strategy also enables to reduce the off-target effects associated with universal treatments and improve the safety profile of a given treatment. The unique optical properties of gold nanoparticles, their ease of surface modification, and high surface-to-volume ratio have made them central players in this area. By combining imaging, targeting, and therapeutic agents in a single vehicle, these nanoconjugates are (ought to be) an important tool in the clinics. In this review, the multifunctionality of gold nanoparticles as theranostics agents will be highlighted, as well as the requirements before the translation of these nanoplatforms into routine clinical practice.

The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) are considered exclusive animal pathogens; however, a putative zoonotic upper limb cellulitis, a prosthetic joint infection and an infective endocarditis were described in humans. To unravel if bovine SDSD isolates are able to infect human cells, the adherence and internalization to human primary keratinocytes of two bovine SDSD strains isolated from milk collected from udder were analyzed. Bacterial adhesion assays and confocal microscopy indicate a high adherence and internalization of SDSD isolates to human cells, suggesting for the first time the ability of bovine isolates to infect human cells.