Nanoarchitectonics of an acetogenin-enriched nanosystem mediated by an aqueous extract ofAnnona cherimolaMill with anti-inflammatory and proapoptotic activity against HepG2 cell line

For the first time, this study shows the nanoarchitectonic process to obtain an acetogenin-enriched nanosystem (AuNPs-Ac) using an aqueous extract from Annona cherimola Mill (ACM) composed of gold nanoparticles embedded in an organic matrix that acts as stabilizing agent and presents anti-inflammatory activity and cytotoxical effect against HepG2 cell line, promoting apoptosis. The synthesis of AuNPs-Ac was confirmed by X-ray diffraction analysis, showing metallic gold as the only phase, and the scanning transmission microscope showed an organic cap covering the AuNPs-Ac. Fourier-transformed infrared suggests that the organic cap comprises a combination of different annonaceous acetogenins, alkaloids, and phenols by the presence of bands corresponding to aromatic rings and hydroxyl groups. High-Performance Liquid Chromatography has demonstrated the presence of annonacin, a potent acetogenin, in the extract of ACM. An in vitro anti-inflammatory activity of the extract of ACM and the AuNPs-Ac was performed using the albumin denaturation method, showing a nonlinear response, which is better than sodium diclofenac salt in a wide range of concentrations that goes from 200 to 400 µg/mL with both samples. The viability assay was studied using trypan blue, treating IMR90 and HepG2 at different concentrations of AuNPs-Ac. The results defined a median lethal dose of 800 µg/mL against HepG2 through apoptosis according to the ratio of caspase-cleaved 9/alpha-tubulin evaluated. It was also demonstrated that the nanosystem presents a higher cytotoxic effect on the HepG2 cell line than in IMR90, suggesting a targeted mechanism. In addition, the nanosystem performs better than using only the extract of ACM in the anti-inflammatory or antiproliferative test, attributed to their higher surface area.

Enhancing antioxidant properties of CeO2 nanoparticles with Nd3+ doping: structural, biological, and machine learning insights

The antioxidant capabilities of nanoparticles are contingent upon various factors, including their shape, size, and chemical composition. Herein, novel Nd-doped CeO2 nanoparticles were synthesized and the neodymium content was varied to investigate the synergistic impact on the antioxidant properties of CeO2 nanoparticles. Incorporating Nd3+ induced changes in lattice parameters and significantly altered the morphology from nanoparticles to nanorods. The biological activity of Nd-doped CeO2 was examined against pathogenic bacterial strains, breast cancer cell lines, and antioxidant models. The antibacterial and anticancer activities of nanoparticles were not observed, which could be associated with the Ce3+/Ce4+ ratio. Notably, the incorporation of neodymium improved the antioxidant capacity of CeO2. Machine learning techniques were employed to forecast the antioxidant activity to enhance understanding and predictive capabilities. Among these models, the random forest model exhibited the highest accuracy at 96.35%, establishing it as a robust computational tool for elucidating the biological behavior of Nd-doped CeO2 nanoparticles. This study presents the first exploration of the influence of Nd3+ on the structural, optical, and biological attributes of CeO2, contributing valuable insights and extending the application of machine learning in predicting the therapeutic efficacy of inorganic nanomaterials.

Potential application of a fungal co-culture crude extract for the conservation of post-harvest fruits

Fungal plant pathogens are responsible for serious losses in many economically important crop species worldwide. Due to the use of fungicides and the fungi genome plasticity, multi-drug resistant strains are emerging as a new generation of pathogens, causing an expansive range of superficial and systemic plant infections, or new opportunistic fungal pathogens for humans. The group of antagonistic fungi Trichoderma spp. has been widely used to enhance plant growth and for the control of different pathogens affecting crops. Although Neurospora crassa is not a mycoparasitic fungus, its secretion of secondary metabolites with antimicrobial activity has been described. In this work, the effect of crude extract of the monoculture of Trichoderma asperellum T8a or the co-culture with N. crassa as an inhibitory treatment against the fungal pathogens Botrytis cinerea and Fusarium solani was evaluated. The findings demonstrate that the secondary metabolites contained in the T. asperellum crude extract have a clear fungistatic activity against B. cinerea and F. solani. Interestingly, this fungistatic activity highly increases when T. asperellum is co-cultivated with the non-pathogenic fungus N. crassa. Moreover, the co-culture crude extract also showed antifungal activity on post-harvest fruits, and no toxic effects on Murine fibroblast L929 (CCL-1) and murine macrophages RAW 264.7 (TIB-71) were observed. All these results together are solid evidence of the potential of the co-culture crude extract of T. asperellum and N. crassa, as an antifungal agent against phytopathogenic fungi, or post-harvest fruits during the transportation or commercialization time.

Lanthanide-Doped ZnO Nanoparticles: Unraveling Their Role in Cytotoxicity, Antioxidant Capacity, and Nanotoxicology

This study used a sonochemical synthesis method to prepare (La, Sm)-doped ZnO nanoparticles (NPs). The effect of incorporating these lanthanide elements on the structural, optical, and morphological properties of ZnO-NPs was analyzed. The cytotoxicity and the reactive oxygen species (ROS) generation capacity of ZnO-NPs were evaluated against breast (MCF7) and colon (HT29) cancer cell lines. Their antioxidant activity was analyzed using a DPPH assay, and their toxicity towards Artemia salina nauplii was also evaluated. The results revealed that treatment with NPs resulted in the death of 10.559-42.546% and 18.230-38.643% of MCF7 and HT29 cells, respectively. This effect was attributed to the ability of NPs to downregulate ROS formation within the two cell lines in a dose-dependent manner. In the DPPH assay, treatment with (La, Sm)-doped ZnO-NPs inhibited the generation of free radicals at IC50 values ranging from 3.898 to 126.948 μg/mL. Against A. salina nauplii, the synthesized NPs did not cause death nor induce morphological changes at the tested concentrations. A series of machine learning (ML) models were used to predict the biological performance of (La, Sm)-doped ZnO-NPs. Among the designed ML models, the gradient boosting model resulted in the greatest mean absolute error (MAE) (MAE 9.027, R2 = 0.86). The data generated in this work provide innovative insights into the influence of La and Sm on the structural arrangement and chemical features of ZnO-NPs, together with their cytotoxicity, antioxidant activity, and in vivo toxicity.

Exploring the cytotoxicity mechanisms of copper ions and copper oxide nanoparticles in cells from the excretory system

Copper oxide nanoparticles (CuO NPs) are widely applied in various products, including food, cosmetic, biomedical, and environmental goods. Despite their broad use, potential risks are still associated with these NPs, therefore, the aim of this study is to delve deeper into the cytotoxic effects of 85 nm CuO NPs on kidney MDCK and liver AML-12 cells, representing cell models from the excretory system. Our findings pointed out that the viability of both cell lines decreased in a concentration-dependent manner when exposed to CuO NPs. Additionally, CuO NPs induced the overproduction of reactive oxygen species (ROS) and caused depolarization of the mitochondrial membrane, thereby arresting the cell cycle at the G2/M phase in MDCK and AML-12 cells. Importantly, unlike others our study uncovered distinctive forms of cellular death induced by CuO NPs in these cell lines. MDCK cells exhibited a combination of apoptosis and autophagy while early apoptosis was predominant in AML-12 cells. Moreover, the role of Cu2+ ions and CuO NPs in exerting cytotoxic effects was investigated, revealing that MDCK cells were affected by both copper ions and NPs. In contrast, AML-12 cells experienced toxic effects solely from CuO NPs. These findings provide crucial insights into the different cell death mechanisms caused either by CuO NPs or Cu2+ ions in excretory system cells in vitro. Nevertheless, further research is needed to explore the underlying mechanisms at the in vivo level, ensuring the safe use of CuO NPs. The results suggest that specific concentrations of metal oxide NPs can impact the physiology of cells within the excretory system of various mammals, including humans, and pave the way for comparing the toxic effects between ions and nanoparticles for further nanotoxicological studies.

Hybrid AuNPs-3MPS-MTX nanosystem and its evaluation for treating cervical cancer and melanoma

This research presents an evaluation of a hybrid material based on gold nanoparticles (AuNPs), stabilized with the thiol 3-mercapto-propanesulfonate (3MPS) and loaded with the methotrexate drug (MTX). The AuNPs-3MPS-MTX nanosystem was tested for the treatment of cervical cancer and melanoma, using the B16-F10 melanoma and HeLa cell lines. The tests performed on cell cultures assessed the efficiency of the studied nanosystem on tumor cells, as well as its toxicology.

Green nanoarchitectonics of carbon quantum dots from Cinchona Pubescens Vahl as targeted and controlled drug cancer nanocarrier

Carbon quantum dots (CQDs) are a new carbon-based nanomaterial that has attracted tremendous attention due to their excellent fluorescent properties, chemical stability, water solubility, and biocompatibility features. Here, fluorescent CQDs synthesized by a green nanoarchitectonic method using Cinchona Pubescens Vahl extract were evaluated as drug nanocarriers for carboplatin (CBP) delivery. The characterization methods showed CQDs with semispherical shapes and sizes around 5 nm, temperature- and pH-dependent functional groups that interact with the CBP molecule adding specificity to the drug-delivery system. Based on the load efficiency results, it seems that the CQDs can carry almost 100 μg of carboplatin for every 1 mg of CQDs. This is possible due to the self-assembly process that takes place through the interaction between the protonation/deprotonation functional groups of CQDs and the hydrolyzed CBP molecule. Through this process, it is created spherical nanoparticles with an average size of 77.44 nm. The CQDs-CBP nanoparticles release the drug through a diffusion-controlled release mechanism where the acidic media is preferred, and the EPR effect also plays a helpful role. Besides, the viability test shows that the CQDs have almost null cytotoxicity suggesting that they could be used as a promising cancer treatment, improving the efficiency of cell internalization and significantly increasing their drug delivery.

Antibacterial Activity of Biosynthesized Copper Oxide Nanoparticles (CuONPs) Using Ganoderma sessile

Copper oxide nanoparticles (CuONPs) were synthesized using an eco-friendly method and their antimicrobial and biocompatibility properties were determined. The supernatant and extract of the fungus Ganoderma sessile yielded small, quasi-spherical NPs with an average size of 4.5 ± 1.9 nm and 5.2 ± 2.1 nm, respectively. Nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS), and zeta potential analysis. CuONPs showed antimicrobial activity against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa). The half-maximal inhibitory concentration (IC50) for E. coli was 8.5 µg/mL, for P. aeruginosa was 4.1 µg/mL, and for S. aureus was 10.2 µg/mL. The ultrastructural analysis of bacteria exposed to CuONPs revealed the presence of small CuONPs all through the bacterial cells. Finally, the toxicity of CuONPs was analyzed in three mammalian cell lines: hepatocytes (AML-12), macrophages (RAW 264.7), and kidney (MDCK). Low concentrations (<15 µg/mL) of CuONPs-E were non-toxic to kidney cells and macrophages, and the hepatocytes were the most susceptible to CuONPs-S. The results obtained suggest that the CuONPs synthesized using the extract of the fungus G. sessile could be further evaluated for the treatment of superficial infectious diseases.

Antibody-Functionalized Copper Oxide Nanoparticles with Targeted Antibacterial Activity

Copper oxide nanoparticles (CuO-NPs) were functionalized with specific antibodies to target their antibacterial activity against Gram-positive or Gram-negative bacteria. The CuO-NPs were covalently functionalized to cover their surface with specific antibodies. The differently prepared CuO-NPs were characterized by X-ray diffraction, transmission electron microscopy and dynamic light scattering. The antibacterial activities of the unmodified CuO-NPs and the antibody-functionalized nanoparticles (CuO-NP-AbGram^- and CuO-NP-AbGram⁺ ) were determined for both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis bacteria. The antibody-functionalized NPs showed a differential increase of their antibacterial activity according to the specific antibody. The CuO-NP-AbGram^- in E. coli showed reduced half maximal inhibitory concentration (IC₅₀ ) and minimum inhibitory concentration (MIC) values when compared with unfunctionalized CuO-NPs. On the other hand, the CuO-NP-AbGram⁺ also showed reduced IC₅₀ and MIC values in B. subtilis, when compared with non-functionalized CuO-NPs. Thus, the functionalized CuO nanoparticles with specific antibodies showed enhanced specificity of their antibacterial activity. The advantages of "smart" antibiotic nanoparticles are discussed.

Highly Antifungal Activity of Biosynthesized Copper Oxide Nanoparticles against Candida albicans

Candida albicans (ATCC SC5314) was exposed to biosynthesized copper oxide nanoparticles (CuONPs) to determine their inhibitory capacity. Nanoparticles were polydisperse of small size (5.8 ± 3.5 nm) with irregular shape. The minimum inhibitory concentration (MIC) against C. albicans was 35.5 µg/mL. The production of reactive oxygen species (ROS) of C. albicans was verified when exposed to different concentrations of CuONPs. Ultrastructural analysis of C. albicans revealed a high concentration of CuONPs in the cytoplasm and outside the cell; also, nanoparticles were detected within the cell wall. Cytotoxic analyses using fibroblasts (L929), macrophages (RAW 264.7), and breast (MCF-12) cell lines show good results of cell viability when exposed at the MIC. Additionally, a hemocompatibility analysis was carried out and was found to be below 5%, considered the threshold for biocompatibility. Therefore, it is concluded that the biosynthesized CuONPs have a high potential for developing a topical antifungal treatment.

Monolayer (2D) or spheroids (3D) cell cultures for nanotoxicological studies? Comparison of cytotoxicity and cell internalization of nanoparticles

Two-dimensional (2D) cell culture monolayers are commonly used for toxicological assessments of nanomaterials. Despite their facile handling, they exhibit several constraints due to their structural and complexity differences with three-dimensional (3D) in vitro cell models, such as spheroids. Here, we conducted a comparative nanotoxicological study of fibroblasts (L929) and melanoma (B16-F10) cells, grown in 2D and 3D arrangements. The cytotoxicity, reactive oxygen species (ROS) production, genotoxicity, cell morphology complexity, and uptake of silver nanoparticles (AgNPs) and folic acid-functionalized upconversion nanoparticles (FA-UCNPs) were compared in the two culture arrangements. AgNPs cytotoxicity was higher in spheroids than in monolayer cultures. Furthermore, apoptotic cell percentages and ROS production were higher in 3D than in 2D cell cultures. More importantly, 2D cultures required twice the concentration of AgNPs than the 3D cell models to reach a considerable DNA damage index (c.a. 200). Therefore, spheroids are more sensitive to the genotoxic effects of AgNPs. FA-UCNPs exerted negligible cell toxicity in 2D and 3D cell models. Moreover, AgNPs induced disaggregation and downsizing of spheroids in a facile and concentration-dependent manner. Internalization of FA-UCNPs in spheroids was 20% higher than in the 2D cell arrangements. Collectively, our findings, demonstrated that spheroids are a more sensitive model than monolayers for the assessment of nanoparticle biocompatibility and internalization.

Optimized Synthesis of Small and Stable Silver Nanoparticles Using Intracellular and Extracellular Components of Fungi: An Alternative for Bacterial Inhibition

Silver nanoparticles (AgNPs) represent an excellent option to solve microbial resistance problems to traditionally used antibiotics. In this work, we report optimized protocols for the production of AgNPs using extracts and supernatants of Trichoderma harzianum and Ganoderma sessile. AgNPs were characterized using UV-Vis spectroscopy and transmission electron microscopy, and the hydrodynamic diameter and Z potential were also determined. The obtained AgNPs were slightly larger using the fungal extract, and in all cases, a quasi-spherical shape was obtained. The mean sizes of AgNPs were 9.6 and 19.1 nm for T. harzianum and 5.4 and 8.9 nm for G. sessile using supernatant and extract, respectively. The AgNPs were evaluated to determine their in vitro antibacterial effect against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The minimum inhibitory concentration (MIC) was determined, and in all cases the AgNPs showed an antimicrobial effect, with a MIC varying from 1.26–5.0 µg/mL, depending on the bacterial strain and type of nanoparticle used. Cytotoxicity analyses of AgNPs were carried out using macrophages and fibroblast cell lines. It was determined that the cell viability of fibroblasts exposed for 24 h to different concentrations of AgNPs was more than 50%, even at concentrations of up to 20 µg/mL of silver. However, macrophages were more susceptible to exposure at higher concentrations of AgNPs as their viability decreased at concentrations of 10 µg/mL. The results presented here demonstrate that small AgNPs are obtained using either supernatants or extracts of both fungal strains. A remarkable result is that very low concentrations of AgNPs were necessary for bacterial inhibition. Furthermore, AgNPs were stable for more than a year, preserving their antibacterial properties. Therefore, the reported optimized protocol using fungal supernatants or extracts may be used as a fast method for synthesizing small AgNPs with high potential to use in the clinic.

Exploring In Vitro Biological Cellular Responses of Pegylated β-Cyclodextrins

βCDPEG5 and βCDPEG2 are two derivatives comprising seven PEG linear chains of 5 and 2 kDa, respectively, conjugated to βCD. As βCDPEGs display different physicochemical properties than their precursors, they could also trigger distinct cellular responses. To investigate the biological behavior of βCDPEGs in comparison to their parent compounds, we performed broad toxicological assays on RAW 264.7 macrophages, MC3T3-E1 osteoblasts, and MDCK cells. By analyzing ROS and NO₂⁻ overproduction in macrophages, we found that βCDPEGs induced a moderate stress response without affecting cell viability. Although MC3T3-E1 osteoblasts were more sensitive than MDCK cells to βCDPEGs and the parent compounds, a similar pattern was observed: the effect of βCDPEG5 on cell viability and cell cycle progression was larger than that of βCDPEG2; PEG2 affected cell viability and cell cycle more than βCDPEG2; cell post-treatment recovery was favorable in all cases, and the compounds had similar behaviors regarding ROS generation. The effect on MDCK cell migration followed a similar pattern. In contrast, for osteoblasts, the interference of βCDPEG5 with cell migration was smaller than that of βCDPEG2; likewise, the effect of PEG2 was shorter than its conjugate. Overall, the covalent conjugation of βCD and PEGs, particularly to yield βCDPEG2, improved the biocompatibility profile, evidencing that a favorable biological response can be tuned through a thoughtful combination of materials. Moreover, this is the first time that an in vitro evaluation of βCD and PEG has been presented for MC3T3-E1 and MDCK cells, thus providing valuable knowledge for designing biocompatible nanomaterials constructed from βCD and PEGs.

Boosting cell proliferation in three-dimensional polyacrylates/nanohydroxyapatite scaffolds synthesized by deep eutectic solvent-based emulsion templating

Among three-dimensional (3D) scaffold fabrication methods, porous polymers templated using high internal phase emulsions (HIPEs) have emerged as an attractive method due to the facile generation of interconnected porosity through a variety of synthetic routes. These include a bottom-up approach to selectively incorporate nanomaterials onto the inner walls in a nonaqueous environment. In this work, novel nonaqueous HIPEs made of different (meth)acrylate monomers and a deep eutectic solvent (DES) were formulated with nonfunctionalized nanohydroxyapatite (NHA), which also played the role of cosurfactant. Free radical polymerization of HIPEs yielded free-standing nanocomposites with 3D interconnected macroporosity and nonfunctionalized NHA selectively decorating the scaffolds' inner surface. The influence of different polymer functionalities, acrylate or methacrylate, their alkyl tail length, and the presence of NHA on MC3T3-E1 preosteoblast cell proliferation in vitro, reactive oxygen species (ROS) production and alkaline phosphatase (ALP) activity were evaluated. All materials presented promising biocompatibility, non-hemolytic activity, negligible inflammatory response along to remarkably enhanced cell proliferation (e.g., up to 160-fold cell proliferation increase compared with polystyrene plate) in vitro, which open the path for the development of scaffolds in regenerative medicine. It is noteworthy that polyHIPEs studied here were obtained using a green synthetic protocol where nonfunctionalized nanoparticles can be selectively incorporated into a scaffolds' inner walls. This versatile technique allows for the simple construction of 3D bioactive nanocomposite scaffolds with varied compositions for cell culture.

Paper-based plasmonic substrates as surface-enhanced Raman scattering spectroscopy platforms for cell culture applications

The engineering of advanced materials capable of mimicking the cellular micro-environment while providing cells with physicochemical cues is central for cell culture applications. In this regard, paper meets key requirements in terms of biocompatibility, hydrophilicity, porosity, mechanical strength, ease of physicochemical modifications, cost, and ease of large-scale production, to be used as a scaffold material for biomedical applications. Most notably, paper has demonstrated the potential to become an attractive alternative to conventional biomaterials for creating two-dimensional (2D) and three-dimensional (3D) biomimetic cell culture models that mimic the features of in vivo tissue environments for improving our understanding of cell behavior (e.g. growth, cell migration, proliferation, differentiation and tumor metastasis) in their natural state. On the other hand, integration of plasmonic nanomaterials (e.g. gold nanoparticles) within the fibrous structure of paper opens the possibility to generate multifunctional scaffolds equipped with biosensing tools for monitoring different cell cues through physicochemical signals. Among different plasmonic based detection techniques, surface-enhanced Raman scattering (SERS) spectroscopy emerged as a highly specific and sensitive optical tool for its extraordinary sensitivity and the ability for multidimensional and accurate molecular identification. Thus, paper-based plasmonic substrates in combination with SERS optical detection represent a powerful future platform for monitoring cell cues during cell culture processes. To this end, in this review, we will describe the different methods for fabricating hybrid paper-plasmonic nanoparticle substrates and their use in combination with SERS spectroscopy for biosensing and, more specifically, in cell culture applications.

Virus-Based Nanoreactors with GALT Activity for Classic Galactosemia Therapy

Enzymatic nanoreactors were obtained by galactose-1-phosphate uridylyl-transferase (GALT) encapsulation into plant virus capsids by a molecular self-assembly strategy. The aim of this work was to produce virus-like nanoparticles containing GALT for an enzyme-replacement therapy for classic galactosemia. The encapsulation efficiency and the catalytic constants of bio-nanoreactors were determined by using different GALT and virus coat protein ratios. The substrate affinity of nanoreactors was slightly lower than that of the free enzyme; the activity rate was 16 % of the GALT free enzyme. The enzymatic nanoreactors without functionalization were internalized into different cell lines including fibroblast and kidney cells, but especially into hepatocytes. The enzymatic nanoreactors are an innovative enzyme preparation with potential use for the treatment of classic galactosemia.

Camouflaged, activatable and therapeutic tandem bionanoreactors for breast cancer theranosis

The one-pot cascade reaction of naturally occurring enzymes is exciting for highly selective complex reaction and biodegradable approaches. Tamoxifen is the main drug against breast cancer for decades and induces an anticancerous effect upon metabolic activation by cytochrome P450 (CYP450). Herein, bi-enzymatic nanoreactors (NRs) are developed as a multimodality platform for smart action against breast tumors. CYP_BM3 of Bacillus magaterium (CYP) is co-confined with glucose oxidase (GOx) where GOx produces H₂O₂ in the presence of glucose that elicits the CYP-mediated transformation of tamoxifen. The scintillating and mesoporous LaF₃:Tb as nanocarrier showed advantages like a wide range of pore size and positive surface charge for efficient loading of enzyme couple, while the smallest pores were available for substrate/product diffusion. The obtained NRs were camouflaged with human serum albumin (HSA) to overcome premature enzyme leaching and provide active stealth properties. The nanocomposite was characterized for physicochemical properties and glucose-mediated sequential catalysis. The in vitro studies demonstrated the cell internalization of NRs in both ER+ and triple-negative breast cancer cell lines and showed significant cytotoxicity. The developed NRs not only improve the outcomes of endocrine therapy in ER+ cells but also synergistically act with oxidation therapy for enhanced therapeutic effect. Importantly, inhibition of triple-negative cells was also achieved. Thus, the development of the new multimodal nanomedicine of the present work should afford new tools towards the theranosis of breast cancer with minimized adverse effects.

Nanotoxicological study of downconversion Y2 O3 :Eu3+ luminescent nanoparticles functionalized with folic acid for cancer cells bioimaging

Luminescent lanthanide downconversion nanoparticles (DCNPs) provide a combination of high luminescence intensity, sharp emission peaks with narrow bandwidth and a large Stokes' shift, leading to high-performance biomedical applications mainly for imaging. The purpose of this study is to present a nanotoxicological study of DCNPs Y₂ O₃ codoped with Eu³⁺ and functionalized with folic acid (FA). These assessments include cytotoxicity, genotoxicity, hemocompatibility, and in vitro inflammatory studies. We demonstrated by flow cytometry and confocal microscope the internalization of FA-DCNPs in breast cancer and melanoma cells. They were synthesized by sol-gel method and coated with a thin silica shell to make them biocompatible; also they were functionalized with amino groups and FA ligands that bind to the folate receptors (FR) located on the surface of the cancer cells studied. This functionalization enables the DCNPs to be internalized into the cancer cells via endocytosis by the conjugation FA-FR. The DCNPs were characterized with transmission electron microscope, Fourier transform infrared spectroscopy and photoluminescence. The nanotoxicological assessments demonstrated that both nanoparticles (bare and functionalized) are no cytotoxic and no genotoxic at the tested concentrations (0.01-20 μg/mL) in three cell lines (breast, skin cancer, and osteoblasts). Also they are hemocompatible and do not exert nitric oxide production in vitro by macrophages. The FA-DCNPs were clearly localized into the cell cytoplasm with bright red luminescence. Thus, herein we present a complete nanotoxicological study of FA-DCNPs Y₂ O₃ codoped with Eu³⁺ and we conclude that these nanoparticles are biocompatible and can be further used for cancer cells bioimaging.

Enhancement of antibiotics antimicrobial activity due to the silver nanoparticles impact on the cell membrane

The ability of microorganisms to generate resistance outcompetes with the generation of new and efficient antibiotics; therefore, it is critical to develop novel antibiotic agents and treatments to control bacterial infections. An alternative to this worldwide problem is the use of nanomaterials with antimicrobial properties. Silver nanoparticles (AgNPs) have been extensively studied due to their antimicrobial effect in different organisms. In this work, the synergistic antimicrobial effect of AgNPs and conventional antibiotics was assessed in Gram-positive and Gram-negative bacteria. AgNPs minimal inhibitory concentration was 10–12 μg mL^-1 in all bacterial strains tested, regardless of their different susceptibility against antibiotics. Interestingly, a synergistic antimicrobial effect was observed when combining AgNPs and kanamycin according to the fractional inhibitory concentration index, FICI: <0.5), an additive effect by combining AgNPs and chloramphenicol (FICI: 0.5 to 1), whereas no effect was found with AgNPs and β-lactam antibiotics combinations. Flow cytometry and TEM analysis showed that sublethal concentrations of AgNPs (6–7 μg mL^-1) altered the bacterial membrane potential and caused ultrastructural damage, increasing the cell membrane permeability. No chemical interactions between AgNPs and antibiotics were detected. We propose an experimental supported mechanism of action by which combinatorial effect of antimicrobials drives synergy depending on their specific target, facilitated by membrane alterations generated by AgNPs. Our results provide a deeper understanding about the synergistic mechanism of AgNPs and antibiotics, aiming to combat antimicrobial infections efficiently, especially those by multi-drug resistant microorganisms, in order to mitigate the current crisis due to antibiotic resistance.

Light sheet microscopy and SrAl2 O4 nanoparticles codoped with Eu2+ /Dy3+ ions for cancer cell tagging

Light sheet optical microscopy on strontium aluminate nanoparticles (SrAl₂ O₄ NPs)1 codoped with Eu²⁺ and Dy³⁺ was used for cancer cell tagging and tracking. The nanoparticles were synthesized by urea-assisted combustion with optimized percentage values of the 2 codoping rare-earth ions for cell viability and for lower cytotoxic effects. The optical properties of these materials showed an excitation wide range of wavelengths (λ_exc = 254-460 nm), a broad emission band (λ_em = 475-575 nm) with the maximum centered wavelength at 525 nm and a half lifetime within the seconds regime. The feasibility to measure the nanoparticle luminescence under the selective plane illumination configuration was studied by immersing the nanoparticles in 1% Agarose. The potential applicability of the synthesized nanophosphors for cancer cell tagging was demonstrated by using in vitro experiments with human breast adenocarcinoma MCF-7 cells. A single MCF-7 cell observed by the use of light sheet microscopy with UV excitation. The cell has been bio-labeled with FA-SrAl₂ 0₄ : Eu²⁺ , Dy³⁺ NPs and 4',6-diamidino-2-phenylindole, dihydrochloride for nucleus identification.

Multifunctionalized biocatalytic P22 nanoreactor for combinatory treatment of ER+ breast cancer

Background

Tamoxifen is the standard endocrine therapy for breast cancers, which require metabolic activation by cytochrome P450 enzymes (CYP). However, the lower and variable concentrations of CYP activity at the tumor remain major bottlenecks for the efficient treatment, causing severe side-effects. Combination nanotherapy has gained much recent attention for cancer treatment as it reduces the drug-associated toxicity without affecting the therapeutic response.

Results

Here we show the modular design of P22 bacteriophage virus-like particles for nanoscale integration of virus-driven enzyme prodrug therapy and photodynamic therapy. These virus capsids carrying CYP activity at the core are decorated with photosensitizer and targeting moiety at the surface for effective combinatory treatment. The estradiol-functionalized nanoparticles are recognized and internalized into ER+ breast tumor cells increasing the intracellular CYP activity and showing the ability to produce reactive oxygen species (ROS) upon UV_365 nm irradiation. The generated ROS in synergy with enzymatic activity drastically enhanced the tamoxifen sensitivity in vitro, strongly inhibiting tumor cells.

Conclusions

This work clearly demonstrated that the targeted combinatory treatment using multifunctional biocatalytic P22 represents the effective nanotherapeutics for ER+ breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s12951-018-0345-2) contains supplementary material, which is available to authorized users.

Effect of silver nanoparticles on the metabolic rate, hematological response, and survival of juvenile white shrimp Litopenaeus vannamei

White spot syndrome virus (WSSV) is highly lethal and contagious in shrimps; its outbreaks causes an economic crisis for aquaculture. Several attempts have been made to treat this disease; however, to date, there is no effective cure. Because of their antimicrobial activities, silver nanoparticles (AgNPs) are the most studied nanomaterial. Although the antiviral properties of AgNPs have been studied, their antiviral effect against viral infection in aquaculture has not been reported. The AgNPs tested herein are coated with polyvinylpyrrolidone (PVP) and possess multiple international certifications for their use in veterinary and human applications. The aim of this work was to evaluate the survival rate of juvenile white shrimps (Litopenaeus vannamei) after the intramuscular administration of AgNPs. For this, different concentrations of metallic AgNPs and PVP alone were injected into the organisms. After 96 h of administration, shrimp survival was more than 90% for all treatments. The oxygen consumption routine rate and total hemocyte count remained unaltered after AgNP injection, reflecting no stress caused. We evaluated whether AgNPs had an antiviral effect in shrimps infected with WSSV. The results revealed that the survival rate of WSSV-infected shrimps after AgNP administration was 80%, whereas the survival rate of untreated organisms was only 10% 96 h after infection. These results open up the possibility to explore the potential use of AgNPs as antiviral agents for the treatment of diseases in aquaculture organisms, particularly the WSSV in shrimp culture.

Comparison of cytotoxicity and genotoxicity effects of silver nanoparticles on human cervix and breast cancer cell lines

The wide application of silver nanoparticles (AgNPs) has pointed out the need to evaluate their potential risk and toxic effects on human health. Herein, the cytotoxic effects of Argovit™ AgNPs were evaluated on eight cancer cell lines. Further cytotoxic studies were performed in gynecological cancer cell lines from cervical (HeLa) and breast (MDA-MB-231 and MCF7) cancer. In both cases, the half maximal inhibitory concentration (IC50) of AgNPs produced the formation of reactive oxygen species (ROS) after 24 h of incubation, but it was not statistically significant compared with untreated cells. However, HeLa, MDA-MB-231, and MCF7 cells treated with the maximal IC of AgNPs induced the formation of ROS either at 12 or 24 h of incubation. Genotoxicity achieved by comet assay in HeLa, MDA-MB-231, and MCF7 cells revealed that exposure to IC50 of AgNPs does not induced noticeable DNA damage in the cells. However, the IC of AgNPs provoked severe DNA damage after 12 and 24 h of exposure. We conclude that, Argovit (polyvinylpyrrolidone-coated AgNPs) induce a cytotoxic effect in a time and dose-dependent manner in all the eight cancer cell lines tested. Nevertheless, the genotoxic effect is mainly restricted by the concentration effect. The results contribute to explore new therapeutic applications of AgNPs for malignances in murine models and to study in deep the cytotoxic and genotoxic effects of AgNPs in healthy cells at the surrounding tissue of the neoplasia.

Aminosilane Functionalization and Cytotoxicity Effects of Upconversion Nanoparticles Y2O3 and Gd2O3 Co-Doped with Yb3+and Er3

In this study, luminescent upconversion nanoparticles (UCNPs) Y₂O₃ and Gd₂O₃ co-doped with Yb³⁺ and Er³⁺ were prepared by the sol-gel method (SG). These NPs are able to absorb near infrared photons and upconvert them into visible radiation with a direct application in bioimaging, as an important tool to diagnose and visualize cancer cells. The UCNPs were coated with a thin silica shell and functionalized with amino groups for further folic acid conjugation to allow their interaction with folate ligands on the cell surface. Their physical properties were analysed by Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence (PL) measurements. The PL results revealed excellent luminescence properties on all core-shell UCNPs. Cytotoxicity experiments with concentrations of bare and aminosilane coated/functionalized UCNPs between 0.001 μg/mL to 1 μg/mL were tested on two different cell lines from human cervix carcinoma (HeLa) and human colorectal adenocarcinoma (DLD-1) with a colorimetric assay based on the reduction of MTT reagent (methy-134-thiazolyltetrazolium). The assays show that some concentrations of bare UCNPs were cytotoxic for cervical adenocarcinoma cells (HeLa); however, for human colorectal adenocarcinoma all UCNPs are non-cytotoxic. After UCNPs functionalization with silica-aminosilane (APTES/TEOS), all of the nanoparticles tested were found to be non-cytotoxic for both cell lines. The UCNPs functionalized in this work can be further conjugated with specific ligands and used as biolabels for detection of cancer cells.

Design of a VLP-nanovehicle for CYP450 enzymatic activity delivery

BACKGROUND

The intracellular delivery of enzymes for therapeutic use has a promising future for the treatment of several diseases such as genetic disorders and cancer. Virus-like particles offer an interesting platform for enzymatic delivery to targeted cells because of their great cargo capacity and the enhancement of the biocatalyst stability towards several factors important in the practical application of these nanoparticles.

RESULTS

We have designed a nano-bioreactor based on the encapsulation of a cytochrome P450 (CYP) inside the capsid derived from the bacteriophage P22. An enhanced peroxigenase, CYPBM3, was selected as a model enzyme because of its potential in enzyme prodrug therapy. A total of 109 enzymes per capsid were encapsulated with a 70 % retention of activity for cytochromes with the correct incorporation of the heme cofactor. Upon encapsulation, the stability of the enzyme towards protease degradation and acidic pH was increased. Cytochrome P450 activity was delivered into Human cervix carcinoma cells via transfecting P22-CYP nanoparticles with lipofectamine.

CONCLUSION

This work provides a clear demonstration of the potential of biocatalytic virus-like particles as medical relevant enzymatic delivery vehicles for clinical applications.

EPR and LC-MS studies on the mechanism of industrial dye decolorization by versatile peroxidase from Bjerkandera adusta

The mechanisms of industrial dye transformation by versatile peroxidase were elucidated. Purified versatile peroxidase from Bjerkandera adusta was able to decolorize different classes of dyes including azo and phthalocyanines, but unable to transform any of the anthraquinones tested. Kinetic constants for selected dyes were determined and the transformation products were analyzed by EPR spectroscopy and mass spectrometry. The EPR and MS analyses of the enzymatic decolorization products showed the cleavage of the azo bond in azo dyes and the total disruption of the phthalocyaninic ring in phthalocyanine dyes. The EPR analysis on two copper-containing dyes, reactive violet 5 (azo) and reactive blue 72 (phthalocyanine), showed that the transformation can or not break the metal-ion coordination bond according the dye nature. The role of the catalytic Trp172 in the dye transformation by a long-range electron transfer pathway was confirmed and the oxidation mechanisms are proposed and discussed.