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Antimicrobial resistance is an ever-growing global concern to public health with no clear or immediate solution. Silver nanoparticles (AgNPs) have long been proposed as efficient agents to fight the growing number of antibiotic-resistant strains. However, the synthesis of these particles is often linked to high costs and the use of toxic, hazardous chemicals, with environmental and health impact. In this study, we successfully produced AgNPs by green synthesis with the aid of the extract of two brown algae—Cystoseira baccata (CB) and Cystoseira tamariscifolia (CT)—and characterized their physico-chemical properties. The NPs produced in both cases (Ag@CB and Ag@CT) present similar sizes, with mean diameters of around 22 nm. The antioxidant activity of the extracts and the NPs was evaluated, with the extracts showing important antioxidant activity. The bacteriostatic and bactericidal properties of both Ag@CB and Ag@CT were tested and compared with gold NPs produced in the same algae extracts as previously reported. AgNPs demonstrated the strongest bacteriostatic and bactericidal properties, at concentrations as low as 2.16 µg/mL against Pseudomonas aeruginosa and Escherichia coli. Finally, the capacity of these samples to prevent the formation of biofilms characteristic of infections with a poorer outcome was assessed, obtaining similar results. This work points towards an alternative for the treatment of bacterial infections, even biofilm-inducing, with the possibility of minimizing the risk of drug resistance, albeit the necessary caution implied using metallic NPs. Graphical abstract

Bacterial and fungal infections are a challenging global problem due to the reported increasing resistance of pathogenic microorganisms to conventional antimicrobials. Nanomaterials are a promising strategy to fight infections caused by multidrug-resistant microbes. In this work, gold (Au@UP) and silver (Ag@UP) nanoparticles were produced for the first time by green synthesis using an aqueous extract of the invasive macroalgae Undaria pinnatifida (UP). The nanoparticles were characterized by a wide range of physicochemical techniques. Au@UP and Ag@UP demonstrated to be spherical and crystalline with an average size of 6.8 ± 1.0 nm and 14.1 ± 2.8 nm, respectively. Carbohydrates and proteins of the UP extract may participate in the synthesis and capping of the nanoparticles. The UP extract, Ag@UP, and Au@UP were assessed for their antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Candida auris. Ag@UP showed the highest antimicrobial activity with very low MIC and MBC values for all the tested bacteria, and Au@UP demonstrated to be very effective against biofilm-producing bacteria. The antifungal properties of both Ag@UP and Au@UP were remarkable, inhibiting hyphae formation. This study points towards a very promising biomedical exploitation of this invasive brown algae.

Sofia Machado,1,* Noelia González-Ballesteros,2,* Anabela Gonçalves,1,3 Luana Magalhães,1 Marisa Sárria Pereira de Passos,4,5 Maria Carmen Rodríguez-Argüelles,2 Andreia Castro Gomes1,3 1Centre of Molecular and Environmental Biology (CBMA), Universidade do Minho, Campus de Gualtar, Braga, 4710-057, Portugal; 2CINBIO, Departamento de Química Inorgánica, Universidade de Vigo, Vigo, 36310, Spain; 3Institute of Science and Innovation for Bio-Sustainability (IB-S), Universidade do Minho, Campus de Gualtar, Braga, 4710-057, Portugal; 4International Iberian Nanotechnology Laboratory (INL), Braga, 4715-330, Portugal; 5European Commission, Joint Research Centre (JRC), Ispra, 21027, Italy*These authors contributed equally to this workCorrespondence: Andreia Castro GomesInstitute of Science and Innovation for Bio-Sustainability (IB-S), Universidade do Minho, Departamento de Biologia, Campus de Gualtar, Braga, 4710-057, PortugalTel +351 253 601511Email agomes@bio.uminho.ptMaria Carmen Rodríguez-ArgüellesCINBIO, Departamento de Química Inorgánica. Universidade de Vigo, Vigo, 36310, SpainTel +34 986 812410Email mcarmen@uvigo.esIntroduction: Research on gold nanoparticles (AuNPs) occupies a prominent place in the field of biomedicine nowadays, being their putative toxicity and bioactivity areas of major concern. The green synthesis of metallic nanoparticles using extracts from marine organisms allows the avoidance of hazardous production steps while maintaining features of interest, thus enabling the exploitation of their promising bioactivity.Objective: To synthesize and characterize AuNPs using, for the first time, macroalga Cystoseira tamariscifolia aqueous extract (Au@CT).Methods: Algal aqueous extracts were used for the synthesis of AuNPs, which were characterized using a wide panel of physicochemical techniques and biological assays.Results: The characterization by UV-Vis spectroscopy, transmission electron microscopy, Z-potential and infrared spectroscopy confirmed that Au@CT were stable, spherical and polycrystalline, with a mean diameter of 7.6 ± 2.2 nm. The antioxidant capacity of the extract, prior to and after synthesis, was analyzed in vitro, showing that the high antioxidant potential was not lost during the synthesis. Subsequently, in vitro and in vivo toxicity was screened, by comparing two species of the genus Cystoseira (C. tamariscifolia and C. baccata) and the corresponding biosynthesized gold nanoparticles (Au@CT and Au@CB). Cytotoxicity was tested in mouse (L929) and human (BJ5ta) fibroblast cell lines. In both cases, only the highest (nominal) test concentration of both extracts (31.25 mg/mL) or Au@CB (12.5 mM) significantly affected cell viability, as measured by the MTT assay. These results were corroborated by a Fish Embryo Acute Toxicity (FET) test. Briefly, it was shown that, at the highest (nominal) tested concentration (31.25 mg/mL), CT extract induced significantly higher cytotoxicity and embryotoxicity than CB extract. However, it was demonstrated that Au@CT, but not Au@CB, were generally non-toxic. At sub-lethal (nominal) test concentrations (1.25 and 2.5 mM), Au@CT affected zebrafish embryonic development to a much lesser extent than Au@CB. In vitro wound healing assays also revealed that, while other experimental conditions did not impact cell migration, CT and Au@CT displayed a moderate positive effect.Conclusion: Au@CT and Au@CB display promising features, desirable for biomedical applications, as wound healing.Keywords: gold nanoparticles, green synthesis, Cystoseira sp., zebrafish embryotoxicity test, bioactivity, toxicity

In the last years, the growth of the world’s population has resulted in an increase in the demand for food. Vegetables and fruit are essential for human nutrition but, regrettably, half the fruit and vegetables produced worldwide are wasted. The food industry generates tons of by-products during processing, for instance, peels, seeds and stems, which still possess bioactive compounds that can be of interest for other applications. The Brassicaceae species includes some of the most consumed vegetables worldwide known for their antioxidant activity associated with the presence of phenolic compounds. In this study, the stems of Brassica oleracea var. acephala cv. Galega (hereafter BG) were employed to prepare an aqueous extract. Then, its antioxidant potential was evaluated by means of the in vitro analysis of its ability to scavenge the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH), the quantification of the total phenolic content and the analysis of the reducing power. Furthermore, the stem aqueous extract was employed to produce gold nanoparticles (AuNPs), acting as a reducing and stabilizing agent. AuNPs were characterized by UV–Visible and Fourier transform infrared spectroscopy. The size and shape of the nanoparticles was analyzed by the acquisition of transmission electron microscopy images, confirming the formation of spherical AuNPs with mean diameters of 25.08 ± 3.73 nm. Finally, three antioxidant assays were performed in the extract after the synthesis of AuNPs. The synthesis of AuNPs employing BG stem extract was revealed to be a good alternative for the revalorization of Brassica by-products.

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG The integral utilization of sustainable resources with versatile, efficient and cleaner processes is encouraged. Hydrothermal treatment with subcritical water is a chemical free, tunable and rapid technology providing enhanced yield compared to conventional extraction and was explored for the benign by design extraction and depolymerization of carrageenan from Chondrus crispus. Up to 90% of the seaweed was solubilized operating under nonisothermal regime during heating up to 200 °C and 75.5% crude carrageenan yield was attained at 140 °C. Crude carrageenan could not be precipitated by ethanol from the extracts produced at 180 °C and higher temperatures, but ultrafiltration (100 kDa) of the extract obtained at 160 °C provided comparable recovery yields and similar rheological features to those of the ethanol precipitated product. Operation at 140 °C was preferred based on the higher recovery yield of the biopolymer and the whole extract was suitable for the green synthesis of polycrystalline decahedral quasi-spherical gold nanoparticles with a mean size distribution of 8.4 nm and Z potential value of −40.2 mV. Alternatively, the crude carrageen fraction was used for the formulation of printable biopolymer based gels with suitable mechanical properties, including a relevant gel strength enhancement (about 10-fold) when compared with conventional procedures. Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-096376-B-I00 Xunta de Galicia | Ref. ED431C 2018/54-GRC Xunta de Galicia | Ref. ED431G2019/06 Ministerio de Ciencia, Innovación y Universidades | Ref. PRE2019-090567 Ministerio de Ciencia, Innovación y Universidades | Ref. RYC2018-024454-I Xunta de Galicia | Ref. ED431F 2020/01

In this paper, we explore the drastic differences in transport properties and catalytic activities for two structural polymorphs of NiP2: cubic (Pa3; No. 205) and monoclinic NiP2 (C2/c; No. 15). Th...

This is the first study to report on the biocompatible and immunogenic properties of one-pot synthesised gold and silver nanoparticles (Au@UI and Ag@UI) using the macroalgae Ulva intestinalis (UI). The UI aqueous extract, Au@UI, and Ag@UI were obtained under sterile conditions and fully characterized by UV-vis spectroscopy, TEM, HRTEM, STEM and FTIR spectroscopy. Moreover, for the first time, the composition of carbohydrates in the UI extract has been reported along with the changes observed after nanoparticle synthesis by size exclusion chromatography, in order to investigate their possible role in the biosynthetic process. This study suggested that the polysaccharide fraction of the extract is involved in the formation and stabilization of the nanoparticles. The potential toxicity of the samples was evaluated using different cell lines and the hemocompatibility was tested in mouse erythrocytes. In addition, ROS production, complement activation and cytokine release were evaluated to determine the immunogenicity. The results showed that Au@UI and Ag@UI exhibit good biocompatibility and hemocompatibility, with the exception of Ag@UI nanoparticles at high concentration, which were hemolytic. The samples induced ROS release and complement activation, two key mechanisms in innate immunity. The samples also induced the release of cytokines from Th1 and Th2 profiles, and other cytokines implicated in the activation of the immune system. Au@UI and Ag@UI were biocompatible and preserved the immunostimulant properties of the UI extract. Hence, Au@UI and Ag@UI could be useful as adjuvants in vaccine development and promote a balanced Th1 and Th2 immune response mediated by ROS production, cytokine release and complement activation.

Carrageenan was extracted from Mastocarpus stellatus using hot water extraction under atmospheric and pressurized conditions. The influence of heating temperature during a non-isothermal heating profile up to temperatures in the range 70-190 °C was studied to evaluate the extraction yields and properties of the carrageenan fraction. Under the selected conditions (130 °C), extracted carrageenan (CMs) was used for the green synthesis of gold nanoparticles (AuNPs). After the optimization of the reaction conditions, the synthesized gold nanoparticles (Au@CMs) were characterized by UV-Vis spectroscopy, Z potential measurements, electron microscopy, and X-ray diffraction analysis, which confirmed the formation of spherical, polycrystalline, and negatively charged nanoparticles with a mean diameter of 14.3 ± 2.1 nm. The study conducted by scanning transmission electron microscopy, energy dispersive X-ray analysis and mapping confirmed the presence of carrageenan stabilizing AuNPs. Finally, Fourier transformed infrared spectroscopy was performed to analyze the functional groups of CMs involved in the reduction and stabilization of AuNPs. The selective cytotoxicity and the antioxidant activity of the Au@CMs were evaluated in different cell lines and compared to the CMs. Au@CMs showed an improved antioxidant capacity in cells under oxidative stress and the induction of apoptosis in a monocytic cell line, while no antitumor effect was observed in a lung endothelial cell line.

Introduction Research on gold nanoparticles (AuNPs) occupies a prominent place in the field of biomedicine nowadays, being their putative toxicity and bioactivity areas of major concern. The green synthesis of metallic nanoparticles using extracts from marine organisms allows the avoidance of hazardous production steps while maintaining features of interest, thus enabling the exploitation of their promising bioactivity. Objective To synthesize and characterize AuNPs using, for the first time, macroalga Cystoseira tamariscifolia aqueous extract (Au@CT). Methods Algal aqueous extracts were used for the synthesis of AuNPs, which were characterized using a wide panel of physicochemical techniques and biological assays. Results The characterization by UV-Vis spectroscopy, transmission electron microscopy, Z-potential and infrared spectroscopy confirmed that Au@CT were stable, spherical and polycrystalline, with a mean diameter of 7.6 ± 2.2 nm. The antioxidant capacity of the extract, prior to and after synthesis, was analyzed in vitro, showing that the high antioxidant potential was not lost during the synthesis. Subsequently, in vitro and in vivo toxicity was screened, by comparing two species of the genus Cystoseira (C. tamariscifolia and C. baccata) and the corresponding biosynthesized gold nanoparticles (Au@CT and Au@CB). Cytotoxicity was tested in mouse (L929) and human (BJ5ta) fibroblast cell lines. In both cases, only the highest (nominal) test concentration of both extracts (31.25 mg/mL) or Au@CB (12.5 mM) significantly affected cell viability, as measured by the MTT assay. These results were corroborated by a Fish Embryo Acute Toxicity (FET) test. Briefly, it was shown that, at the highest (nominal) tested concentration (31.25 mg/mL), CT extract induced significantly higher cytotoxicity and embryotoxicity than CB extract. However, it was demonstrated that Au@CT, but not Au@CB, were generally non-toxic. At sub-lethal (nominal) test concentrations (1.25 and 2.5 mM), Au@CT affected zebrafish embryonic development to a much lesser extent than Au@CB. In vitro wound healing assays also revealed that, while other experimental conditions did not impact cell migration, CT and Au@CT displayed a moderate positive effect. Conclusion Au@CT and Au@CB display promising features, desirable for biomedical applications, as wound healing.

Macroalgae are sources of bioactive compounds that are interesting from both a chemical and a medical point of view. Although their use in biomedicine has increased significantly in recent years, tests conducted to date have been mostly related to species from temperate latitudes, with the potential application of Antarctic biodiversity being minor. The wide variety of algae species present on Antarctic coastal areas can be a source of new antioxidants. Bearing this in mind, the brown macroalgae Desmarestia antarctica (DA) and the red Iridaea cordata (IC) were selected for the preparation of aqueous extracts with the aim of analyzing their antioxidant activity. This analysis was performed by determining reducing power, total phenolic content, and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. Furthermore, both extracts were employed to synthesize gold and silver nanoparticles. The nanomaterials were fully characterized by means of UV-Visible spectroscopy, transmission electron microscopy, Z potential measurements, and Fourier transform infrared spectroscopy, which confirmed the formation of stable, spherical nanoparticles with mean diameters of 13.7 ± 3.1 and 17.5 ± 3.7 nm for Ag@DA and Ag@IC and 12.6 ± 1.9 and 12.3 ± 1.6 nm for Au@DA and Au@IC. Antioxidant assays were performed after the synthesis of the nanomaterials to evaluate their possible synergistic effect with the extracts. The results suggest that polysaccharides and proteins may play a key role in the process of reduction and stabilization. Finally, for the sake of comparison, the results obtained for the Antarctic macroalgae Desmarestia menziesii and Palmaria decipiens have also been considered in the present work. Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia | Ref. ED431C 2017/46-GRC Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia | Ref. ED431C 2018/54 -GRC

Over the last years, there has been an increasing trend towards the use of environmentally friendly processes to synthesize nanomaterials. In the case of nanomedicine, the use of bionanofactories with associated biological properties, such as seaweed, has emerged as a promising field of work due to the possibility they open for both the preservation of those properties in the nanomaterials synthesized and/or the reduction of their toxicity. In the present study, gold (Au@SP) and silver (Ag@SP) nanoparticles were synthesized using an aqueous extract of "Saccorhiza polyschides" (SP). Several techniques showed that the nanoparticles formed were spherical and stable, with mean diameters of 14 ± 2 nm for Au@SP and 15 ± 3 nm for Ag@SP. The composition of the biomolecules in the extract and the nanoparticles were also analyzed. The analyses performed indicate that the extract acts as a protective medium, with the particles embedded in it preventing aggregation and coalescence. Au@SP and Ag@SP showed superior immunostimulant and antiproliferative activity on immune and tumor cells, respectively, to that of the SP extract. Moreover, the nanoparticles were able to modulate the release of reactive oxygen species depending on the concentration. Hence, both nanoparticles have a significant therapeutic potential for the treatment of cancer or in immunostimulant therapy. Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Xunta de Galicia | Ref. ED431C 2017/46-GRC Xunta de Galicia | Ref. ED431C 2018/54-GRC Xunta de Galicia | Ref. GRC2013-004 Xunta de Galicia | Ref. ED481A-2018/294

In the last few years, nanotechnology has emerged has a multidisciplinary science with a growing number of applications. Among the nanomaterials developed, gold and silver nanoparticles present physicochemical properties that attract the attention of several researchers all over the world. Seaweeds are a great source of bioactive compounds with a wide variety of applications. Recently, they have been named as “bionanofactories” due to their ability for the synthesis of metal nanoparticles. The development of green synthesis methods is in potential growth because, among other advantages, they reduce the use of toxic and expensive reagents, thus being ecofriendly and cost-effective. In this chapter, we present a review of the synthesis of gold and silver nanoparticles led by macroalgae in the last 5 years (2014–19), with a focus on the different reaction conditions, the size and shape of the nanoparticles synthesized, and their applications.

In this study, two Antarctic macroalgae (Rhodophyta Palmaria decipiens and Phaeophyta Desmarestia menziessi) were selected in order to report their use for the biosynthesis of nanomaterials. Two aqueous extracts of the macroalgae were prepared and their reducing activity, total phenolic content and DPPH scavenging activity were determined, showing that brown seaweed has higher antioxidant activity than red seaweed. Aqueous extracts were used as an eco-friendly, one-pot synthetic route to obtain gold and silver nanoparticles acting both as reducing and stabilizing agents. The nanoparticles obtained were characterized by UV–Vis spectroscopy and Transmission electron microscopy (TEM), demonstrating the formation of gold and silver nanoparticles with mean diameters of 36.8 ± 5.3 and 11.5 ± 3.3 nm for Au@PD and Au@DM and 7.0 ± 1.2 nm and 17.8 ± 2.6 nm in the case of Ag@PD and Ag@DM. Lastly, functional groups of the biomolecules present in the extracts were characterized by Fourier transform infrared spectra (FTIR) prior to, and after, the synthesis of the nanoparticles, in order to obtain information about the biomolecules involved in the reducing and stabilization process., 本研究では、ナノ物質の生合成に使用することを報告するために、2種の南極産大型藻類（紅藻のPalmaria decipiens, PMおよび褐藻のDesmarestia menziessi, DM）を選択した。これら藻類の2つの水性抽出物を調製し、それらの還元活性、全フェノール含量およびDPPH捕捉活性を測定したところ、褐藻類は紅藻類よりも高い抗酸化活性を有することが示された。水性抽出物は、還元剤および安定剤の両方として作用する金および銀ナノ粒子を得るために、環境にやさしいワンポット合成経路として使用された。得られたナノ粒子は、紫外可視分光法および透過型電子顕微鏡によって調べられ、大型藻類2種の金ナノ粒子（Au@PDおよびAu@DM）の平均直径は、それぞれ36.8±5.3および11.5±3.3nm、銀ナノ粒子（Ag@PDおよびAg@DM）の平均直径は、それぞれ7.0±1.2および17.8±2.6nmであった。最後に、抽出物中に存在する生体分子の官能基は、還元および安定化プロセスに関与する生体分子に関する情報を得るために、ナノ粒子の合成の前後にフーリエ変換赤外分光分析（FTIR）によって調べられた。

In recent years, the management of food waste processing has emerged as a major concern. One such type of food waste, grape pomace, has been shown to be a great source of bioactive compounds which might be used for more environmentally - friendly processes for the synthesis of nanomaterials. In this study, grape pomace of Vitis vinifera has been used for the obtainment of an aqueous extract. Firstly, the reducing activity, total phenolic content and DPPH scavenging activity of the aqueous extract were determined. Then, the aqueous extract was used for the synthesis of gold and silver nanoparticles. The formation of spherical and stable nanoparticles with mean diameters of 35.3 ± 5.2 nm for Au@GP and 42.9 ± 6.4 nm for Ag@GP was confirmed by UV–vis spectroscopy and transmission electron microscopy. Furthermore, the functional group of biomolecules present in grape pomace extract, Au@GP and Ag@GP, were characterized by Fourier transform infrared spectroscopy prior to and after the synthesis, in order to obtain information about the biomolecules involved in the reducing and stabilization process. This study is the first to deal with the use of Vitis vinifera grape pomace in obtaining gold and silver nanoparticles through an eco-friendly, quick, one-pot synthetic route.

Crude fucoidans from Sargassum muticum obtained by hot water extraction at 40–80 °C were used for the synthesis of gold nanoparticles (AuNPs). The effect of operation temperature on the yield and properties of the extract was determined. The alginate fraction partially coextracted precipitated as calcium alginate and showed rheological properties slightly lower than those of commercial alginates reported elsewhere. The fraction of fucoidan with a larger amount of sulfate, obtained at 60 °C (45% saccharide, 22% fucose, 24% sulfate), also contained 8.5% phlorotannins and 3% protein, as well as showing 37% the 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonate) (ABTS) radical scavenging capacity of Trolox. This soluble product was used for optimization during the synthesis of AuNPs. Several reaction conditions were tested until the obtainment of homogeneous nanoparticles. The characterization of the synthesized nanoparticles was performed employing ultraviolet-visible spectroscopy, Z potential, transmission electron microscopy and Fourier transformed infrared spectroscopy.

This study is the first dealt with the use of brown macroalgae Cystoseira baccata (CB) extracts in obtaining gold nanoparticles (Au@CB) through an eco-friendly, fast, one-pot synthetic route. The formation of spherical, stable, polycrystalline nanoparticles with mean diameter of 8.4±2.2nm was demonstrated by UV-vis spectroscopy, TEM, HRTEM, STEM and zeta potential measurements. The extract appears to act as a protective agent where the particles are embedded, keeping them separated, avoiding aggregation and coalescence. The EELS and EDS analyses confirmed the elemental composition of the extract and nanoparticles. Moreover, the functional group of biomolecules present in CB and Au@CB were characterized by FTIR. The effects of CB extract and Au@CB were tested in vitro on the colon cancer cell lines HT-29 and Caco-2, as well as on normal primary neonatal dermal fibroblast cell line PCS-201-010. Results show a stronger cytotoxic effect against HT-29 than that on Caco-2; interestingly, a lack of toxicity on PCS-201-010 was obtained. Finally, the apoptotic activity was determined; Au@CB is able to induce apoptosis activation by the extrinsic and mitochondrial pathway in our CRC in vitro model. These encouraging results suggest that Au@CB has a significant potential for the treatment of colon rectal cancer.

Three novel copper(I) complexes with three methyl 4-aryl-6-methyl-3,4-dihydropyrimidine-2(1H)-thione-5-carboxylate ligands were synthesized and fully characterized by elemental analysis, magnetic susceptibility, molar conductivity, ESI-MS, FTIR, UV–Vis and NMR. The difference between the three ligands is located in the aryl group: 4-(tert-butyl)phenyl (HL1), 2,6-dichlorophenyl (HL2) and 2,4-dichlorophenyl (HL3). Two ligands and complex 2 were characterized by single-crystal X-ray diffraction. The complex [CuCl(HL2)2]·dmso exhibits an almost perfect trigonal planar coordination geometry crystallizing in a space group P21/n, through the two sulfur atoms of the ligands, one chlorine atom bonded to the copper(I) and solvated with one molecule of dimethyl sulfoxide. The anticancer activity was evaluated in vitro against human colorectal cancer (CRC) cell line (Caco-2). The complexes have cytotoxic effect with IC50 values of 28.46, 25.03 and 38.83 μM respectively. Moreover, complexes 1 and 2 are able to strongly induce apoptosis in this CRC in vitro model.

The marine ecosystem has captured a major attention in recent years since various biologically active compounds have been isolated and screened for pharmacological activity from dissimilar marine provenience. Marine biological resources can be considered an essential for nanotechnology, researchers had been interested to synthesize metallic nanoparticles from marine source because it is thought to be ecofriendly, nontoxic, environmentally acceptable ‘‘green procedures”, reduces the down-streaming process making it very cost effective and the availableness of the source from the diverse marine ecosystem becomes a much easier task. The biosynthesized nanoparticles from marine compound offer stabilized nanoparticles through compounds present in the marine source that make them more efficient for both biomedical and industrial applications[1]. In this regard, we have focus our attention in two algae of Cystoseira. It is a genus of marine brown macroalgae composed of about 40 species. It is widely distributed in the North East Atlantic, the Baltic Sea and the Mediterranean. This genus contains a wide variety of secondary metabolites (e.g. terpenoids, steroids, phlorotannins, phenolic compounds, carbohydrates, triacylglycerols/fatty acids, pigments, vitamins) that are associated with pharmacological properties, such as antioxidant, anti-inflammatory, cytotoxicity, anticancer, cholinesterase inhibition and anti-diabetic activities but also antibacterial, antifungal and anti-parasitic activities [2]. Cystoseira baccata (CB) and Cystoseira tamariscifolia (CT) are two species of this genus that differ in geographic distribution, morphology and possibly content of secondary metabolites. Gold nanoparticles are presently under intensive study since they can be the remarkable scaffold for novel biological and chemical applications owing to their unique electrical, chemical and optical properties. Such as their easy synthesis and good biocompatibility due to the low reactivity of the golden core. Therefore presenting potential applications in the development of new technologies in different fields such as in the food, cosmetic and pharmaceutical industry [3,4]. Previously, González-Ballesteros et al have reported the synthesis of gold nanoparticles with antitumor activity led by the macroalga CB [5]. In the present study, we have compared the ability of C. baccata and C. tamariscifolia (CT) in the synthesis of gold nanoparticles. With this aim, aqueous extracts of the two macroalgae were prepared and their reducing activity, total phenolic content and DPPH scavenging activity were determined before and after the synthesis of nanoparticles. Results showed that CT possess three times more reducing power, almost 4 times more phenolic content and 4 time more DPPH scavenging activity than CB. The nanoparticles obtained were characterized by UV-Vis spectroscopy and Transmission electron microscopy confirming the formation of spherical nanoparticles with a mean diameter of 8.4 ± 2.2 nm in the case of Au@CB and 7.6 ± 2.2 nm for Au@CT. In order to compare the biological potential of both CT and CB extracts and their respective gold nanoparticles (Au@CT and Au@CB), it was investigated whether they affect the viability in mouse (L929 cell line) and human (BJ5-ta cell line) fibroblast cells as in vitro models, by evaluating cellular metabolism by tetrazolium-based colorimetric cellular assay (MTT); cell membrane integrity by lactate dehydrogenase activity (LDH); wound-healing assay to asses effects on cell proliferation and migration capacity. Both algae extracts and derived nanoparticles present a non-cytotoxic profile in lower concentrations, which are efficient in cell regeneration, although with some differences between both species. For a correlation between in vitro and in vivo toxicity, the zebrafish embryo toxicity (ZET) assay, recomended by OECD to evaluate acute and chronic toxicity, was performed. This model organism has a translucent body, allowing real time observation, and allows the evaluation of whole organism responses, from mortality to more specific parameters such as neurotoxicity. The results show that toxicity is evident only at very high concentrations. These promising results thus support that green synthesis in CB and CT extracts of non-toxic, bioactive nanoparticles have an interesting potential for biomedical applications., This work was supported by the strategic programme UID/BIA/04050/2019 funded by national funds through the Fundação para a Ciência e a Tecnologia I.P. (FCT, IP), FUN2CYT (POCI-01-0145-FEDER-030568) supported by Programa Operacional Competitividade e Internacionalização (FEDER) and FCT, IP. This work was also supported by the Xunta de Galicia ED431C 2018/54-GRC. NGB acknowledges a fellowship from Universidade de Vigo.

Chalcogenide semiconducting nanoparticles are promising building blocks for solution-processed fabrication of optoelectronic devices. In this work, we report a new large-scale colloidal synthesis of metastable CuInSe2 nanoparticles with hexagonal plate-like morphology. Powder X-ray diffraction analysis of the nanoparticles showed that the structure of the nanoparticles is not simple hexagonal wurtzite-type CuInSe2 (space group P63mc), indicating the formation of an ordered superstructure. Detailed insight into this structural aspect was explored by high-resolution electron microscopy, and the results evidence an unreported chemical ordering within the synthesized CuInSe2 nanoparticles. Specifically, while the Se sublattice is arranged in perfect wurtzite subcell, Cu and In are segregated over distinct framework positions, forming domains with lower symmetry. The arrangement of these domains within the hexagonal Se substructure proceeds through the formation of a number of planar defects, mainly twins and antiphase boundaries. As a semiconductor, the synthesized material exhibits a direct optical transition at 0.95 eV, which correlates well with its electronic structure assessed by density functional theory calculations. Overall, these findings may inspire the design and synthesis of other nanoparticles featuring unique chemical ordering; thus, providing an additional possibility of tuning intrinsic transport properties., This work was supported by ERDF COMPETE 2020 and Portuguese FCT funds under the PrintPV project (PTDC/CTM-ENE/5387/2014, Grant Agreement No. 016663). B.F.G. is grateful to the FCT for the SFRH/BD/121780/2016 grant, while Y.V.K. is grateful to Portuguese NORTE 2020 programme (FROnTHERA project, NORTE-01-0145- FEDER-000023) for support of this research.

New copper(I) complexes of four methyl 4-aryl-6-methyl-3,4-dihydropyrimidine-2(1H)-thione-5-carboxylate ligands, where the aryl group is phenyl (HL1), 1-naphthalenyl (HL2), 2-bromophenyl (HL3) and 2-chlorophenyl (HL4), have been synthesized. Structural characterization was carried out using different techniques, such as elemental analysis, mass spectrometry, molar conductivity, magnetic susceptibility, FTIR, UV–Vis/luminescence and NMR spectroscopies, and allowed us to propose the general formula [CuCl(HL)2] for all complexes. Furthermore, X-ray studies of ligands HL2 and HL3 and the complex [CuCl(HL2)2]·3dmso have been performed. The complex crystallizes in the triclinic space group P 1 ¯ and adopts a less common, almost perfect, trigonal planar coordination geometry, through the two sulfur atoms of the ligands and one chlorine atom bonded to the metal. The intramolecular hydrogen bonds between the chlorine and the N1H stabilize the structure of the complex. Evaluation of the in vitro activity against human breast cancer representatives of hormonal receptor positive (MCF7) and triple negative (HCC1806) tumors revealed a higher activity in the complexes than in the ligands. Considering particularly HCC1806 cells for which no targeted treatment is available, complexes [CuCl(HL1)2] and [CuCl(HL3)2] exhibited IC50 values of 5.51 and 5.30 μM, respectively, which are lower than the currently used chemotherapeutic drugs.

Marine bio-resources are being widely studied as an invaluable source of compounds with therapeutic applicability. In particular, macroalgae contain an extended variety of bioactive compounds with different structures and promising biological applications. In this work, Ulva lactuca L. (hereafter UL) was utilyzed for the synthesis of gold and silver nanoparticles. Full characterization by UV-Vis spectroscopy, TEM, HRTEM and STEM miscroscopies, Z Potential and FTIR spectroscopy was performed. The first time in the scientific literature, the composition of carbohydrates of UL extract and their changes observed after nanoparticles synthesis were explored in order to investigate their possible role in the biosynthetic process. The reducing power, total phenolic content and DPPH scavenging activity of UL extract, Au@UL and Ag@UL nanoparticles were determined. The effects of UL extract, Au@UL and Ag@UL were tested in vitro on the colon cancer cell lines HT-29 and Caco-2, on normal primary neonatal dermal fibroblast cell line PCS-201-010, as well as on normal colon cell line CCD-112CoN. Lastly, the apoptotic activity and cellular uptake evaluation was determined for Au@UL and Ag@UL.

Cancer is not a static disease that can be easily monitored and treated. It is a dynamic, time-dependent and environment-dependent pathology in which all molecular and cellular interactions are constantly reshaped in response to environmental stimuli. None of the current treatment approaches, which include the combination of tumour removal by surgery, chemotherapy or radiation, are exempt of problems. Surgical removal has been the cornerstone of treatment for most types of cancer but it is limited to accessible tumours. Chemotherapy and radiation, which are used to eradicate the remaining cancer cells after tumour reduction, produce toxicity problems and can cause damage to the healthy tissues to different degrees. Against this backdrop, nanomedicine, with a variety of non-metallic and metallic nanomaterials, has emerged as a promising option in the fight against cancer. Here, we review some metallic nanomaterials and their applications in cancer nanotheragnosis. In particular, we focus on the latest studies carried out over the last five years related to gold, silver and iron nanomaterials’ use in Cancer Imaging, Drug Delivery, Gene Therapy and Thermotherapy.

We report excellent electrocatalytic performance by AlFe2B2 in the oxygen-evolution reaction (OER). The inexpensive catalytic material, prepared simply by arc-melting followed by ball-milling, exhibits high stability and sustained catalytic performance under alkaline conditions. The overpotential value of 0.24 V observed at the current density of 10 mA cm−2 remained constant for at least 10 days. Electron microscopy and electron energy loss spectroscopy performed on the initial ball-milled material and on the material activated under electrocatalytic conditions suggest that the catalytic mechanism involves partial leaching of Al from the layered structure of AlFe2B2 and the formation of Fe3O4 nanoclusters on the exposed [Fe2B2] layers. Thus, the AlFe2B2 structure serves as a robust supporting material and, more importantly, as a pre-catalyst to the in situ formed active electrocatalytic sites. Comparative electrochemical measurements demonstrate that the electrocatalytic performance of the AlFe2B2-supported Fe3O4 nanoclusters substantially exceeds the results obtained with unsupported nanoparticles of Fe3O4, FeB, or such benchmark OER catalysts as IrO2 or RuO2. The excellent catalytic performance and long-term stability of this system suggests that AlFe2B2 can serve as a promising and inexpensive OER electrocatalyst Petroleum Research Fund of the American Chemical Society | Ref. 59251-ND10 U.S. National Science Foundation | Ref. DMR-1507233 European Commission | Ref. H2020, n. 686053 European Commission | Ref. NORTE-01-0145-FEDER-000023 Agence Nationale de la Recherche | Ref. ANR11-EQPX-0020