Nano red elemental selenium has no size effect in the induction of seleno-enzymes in both cultured cells and mice

Cascade targeting selenium nanoparticles-loaded hydrogel microspheres for multifaceted antioxidant defense in osteoarthritis

Selenium (Se) deficiency is a critical factor contributing to the imbalance of redox homeostasis in chondrocytes and the progression of osteoarthritis (OA). However, traditional selenium supplements face challenges such as a narrow therapeutic window and lack of targeting. To address this, we designed hyaluronic acid (HA)-modified selenium nanoparticles (HA-SeNPs) and developed a cascade-targeted delivery system (HA-SeNPs@AHAMA-HMs) based on a nano-micron combined strategy. The system involves loading HA-SeNPs into aldehyde-functionalized hydrogel microspheres prepared via microfluidic technology. Through Schiff base reactions between the aldehyde groups of the microspheres and amino groups of the cartilage, the system selectively adheres to the surface of damaged cartilage, achieving micron-scale targeting while continuously releasing HA-SeNPs. Then, HA-SeNPs achieve nanoscale targeting by binding to CD44, which is highly expressed on OA chondrocyte membranes, via their HA surface. Once taken up by the cells, HA-SeNPs exert their effects by directly scavenging ROS and promoting selenoprotein synthesis through the generation of selenite, forming a multifaceted antioxidant defense system. This effectively alleviates oxidative stress and optimizes mitochondrial function. In vivo and in vitro results demonstrated that this system significantly improved the oxidative phosphorylation pathway associated with mitochondrial function, which markedly reduced joint space narrowing and cartilage matrix degradation, and delayed the progression of OA. In summary, this study suggests that the cascade-targeting hydrogel microspheres designed and constructed based on a nano-micron combined strategy represent a promising prospective approach for precise Se supplementation and OA treatment.

Selenium-Albumin Nanoaccelerator Hydrogel Promotes Wound Healing by Antibacterial, Anti-Inflammatory and Antioxidant along with Inhibits Scar Formation via Downregulating CD36

Wounds repairing after skin damage or diabetes remain a vast medical challenge, which often faces infection, inflammation, oxidative stress, and skin scarring. Herein, a multifunctional selenium-albumin nanoaccelerator hydrogel (H-Se NPs-Gel) is constructed based on the self-assembly of human serum albumin (HSA) with selenium nanoparticles (Se NPs) using carbomer as the carrier, it has remarkable antibacterial, anti-inflammatory, antioxidant and inhibits scarring properties than Se NPs for wound healing. Compared with Se NPs, H-Se NPs exhibit smaller particle sizes, exceptional stability, better antibacterial activity against common bacteria and MRSA, and superior antioxidant and anti-inflammatory capabilities in vitro without remarkable toxicity on skin cells. Importantly, it exhibits superior efficacy to Se NPs-Gel in accelerating the healing of full-thickness skin defects and diabetic wounds in mice. Interestingly, in a hypertrophic scar (HTS) model, H-Se NPs-Gel is more effective than Se NPs-Gel in inhibiting collagen formation to suppress scarring, which is mediated by the inhibition of CD36. The antagonistic effect of H-Se NPs on CD36 is also proved with the CD36 overexpression model. Furthermore, H-Se NPs-Gel demonstrates excellent safety in mice without systemic toxicity. H-Se NPs-Gel is an effective and safe therapy strategy for promoting wound healing and reducing scar formation in clinic.

Human Serum Albumin/Selenium Complex Nanoparticles Protect the Skin from Photoaging Injury

Introduction

Photoaging-induced skin damage leads to appearance issues and dermatoma. Selenium nanoparticles (SeNPs) possess high antioxidant properties but are prone to inactivation. In this study, human serum albumin/SeNPs (HSA-SeNPs) were synthesized for enhanced stability.

Methods

HSA-SeNPs were prepared by self-assembling denatured human serum albumin and inorganic selenite. The cytotoxicity of HSA-SeNPs was assessed using the MTT method. Cell survival and proliferation rates were tested to observe the protective effect of HSA-SeNPs on human skin keratinocytes against photoaging. Simultaneously, ICR mice were used for animal experiments. H&E and Masson trichromatic staining were employed to observe morphological changes in skin structure and collagen fiber disorders after UVB irradiation. Quantitative RT-PCR was utilized to measure changes in mRNA expression levels of factors related to collagen metabolism, inflammation, oxidative stress regulation, and senescence markers.

Results

The HSA-SeNPs group exhibited significantly higher survival and proliferation rates of UVB-irradiated keratinocytes than the control group. Following UVB irradiation, the back skin of ICR mice displayed severe sunburn with disrupted collagen fibers. However, HSA-SeNPs demonstrated superior efficacy in alleviating these symptoms compared to SeNPs alone. In a UVB-irradiated mice model, mRNA expression of collagen type I and III was dysregulated while MMP1, inflammatory factors, and p21 mRNA expression were upregulated; concurrently Nrf2 and Gpx1 mRNA expression were downregulated. In contrast, HSA-SeNPs maintained the mRNA expression of those factors to be stable In addition, the level of SOD decreased, and MDA elevated significantly in the skin after UVB irradiation, but no significant differences in SOD and MDA levels between the HSA-SeNPs group with UVB irradiation and the UVB-free untreated group.

Discussion

HSA-SeNPs have more anti-photoaging effects on the skin than SeNPs, including the protective effects on skin cell proliferation, cell survival, and structure under photoaging conditions. HSA-SeNPs can be used to protect skin from photoaging and repair skin injury caused by UVB exposure.

Preparation, Characterization, and Bioactivities of Polysaccharide-Nano-Selenium and Selenized Polysaccharides from Acanthopanax senticosus

Acanthopanax senticosus polysaccharide-nano-selenium (ASPS-SENPS) and A. selenopanax selenized polysaccharides (Se-ASPS) were synthesized, and their characterization and biological properties were compared. The acid extraction method was used to extract the polysaccharides of A. selenopanax, followed by decolorization using the hydrogen peroxide method and deproteinization based on the Sevage method, and the purification of A. senticosus polysaccharides (ASPS) was carried out using the cellulose DEAE-52 ion column layer analysis method. An A. senticosus polysaccharide-nano-selenium complex was synthesized by a chemical reduction method using ASPS as dispersants. The selenization of polysaccharides from A. selenopanax was carried out using the HNO3-Na2SeO3 method. The chemical compositions, scanning electron microscopy images, infrared spectra, and antioxidant properties of ASPS-SENPS and Se-ASPS were studied, and they were also subjected to thermogravimetric analysis. The results indicated that the optimal conditions for the synthesis of ASPS-SENPS include the following: when ASPS accounts for 10%, the ratio of ascorbic acid and sodium selenium should be 4:1, the response time should be 4 h, and the reaction temperature should be 50 °C. The most favorable conditions for the synthesis of Se-ASPS were as follows: m (Na2SeO3):m (ASPS) = 4:5, response temperature = 50 °C, and response time = 11.0 h. In the in vitro antioxidant assay, when the mass concentration of Se-ASPS and ASPS-SENPS was 5 mg/mL, the removal rates for DPPH free radicals were 88.44 ± 2.83% and 98.89 ± 3.57%, respectively, and the removal rates for ABTS free radicals were 90.11 ± 3.43% and 98.99 ± 1.73%, respectively, stronger than those for ASPS. The current study compares the physiological and bioactivity effects of ASPS-SENPS and Se-ASPS, providing a basis for future studies on polysaccharides.

A Snapshot of Selenium-enclosed Nanoparticles for the Management of Cancer

Among the primary causes of mortality in today's world is cancer. Many drugs are employed to give lengthy and severe chemotherapy and radiation therapy, like nitrosoureas (Cisplatin, Oxaliplatin), Antimetabolites (5-fluorouracil, Methotrexate), Topoisomerase inhibitors (Etoposide), Mitotic inhibitors (Doxorubicin); such treatment is associated with significant adverse effects. Antitumor antibiotics have side effects similar to chemotherapy and radiotherapy. Selenium (Se) is an essential trace element for humans and animals, and additional Se supplementation is required, particularly for individuals deficient in Se. Due to its unique features and high bioactivities, selenium nanoparticles (SeNPs), which act as a supplement to counter Se deficiency, have recently gained worldwide attention. This study presented a safer and more economical way of preparing stable SeNPs. The researcher has assessed the antiproliferative efficiency of SeNPs-based paclitaxel delivery systems against tumor cells in vitro with relevant mechanistic visualization. SeNPs stabilized by Pluronic F-127 were synthesized and studied. The significant properties and biological activities of PTX-loaded SeNPs on cancer cells from the lungs, breasts, cervical, and colons. In one study, SeNPs were formulated using chitosan (CTS) polymer and then incorporated into CTS/citrate gel, resulting in a SeNPs-loaded chitosan/citrate complex; in another study, CTS was used in the synthesis of SeNPs and then situated into CTS/citrate gel, resulting in Se loaded nanoparticles. These formulations were found to be more successful in cancer treatment.

Advances in the Synthesis and Bioactivity of Polysaccharide Selenium Nanoparticles: A Review

Selenium, an essential trace element of the human body, is pivotal in human health and disease prevention. Nevertheless, the narrow therapeutic index of selenium, where the toxic and therapeutic doses are close, limits its clinical utility. Significantly, nanoscale selenium synthesized by different methods using polysaccharides as stabilizers has low toxicity properties and exhibits excellent bioactivity. Its biological activities, such as anti-tumor, anti-inflammatory, antioxidant, antibacterial, and immune function enhancement, are improved compared with traditional organic and inorganic selenium compounds, conferring greater potential for application in biomedicine. Therefore, this review evaluates the advancements in various synthesis methodologies for polysaccharide selenium nanoparticles (Se NPs) and their biological activities. It aims to provide a comprehensive theoretical basis and research directions for the future development of highly efficient, minimally toxic, and biocompatible polysaccharide-Se NPs and the application of polysaccharide-Se NPs in biomedicine.

Preparation of polysaccharide-conjugated selenium nanoparticles from spent mushroom substrates and their growth-promoting effect on rice seedlings

Selenium nanoparticles (SeNPs) have gained significant attention in the agricultural field due to their favorable bioavailability and low toxicity, making them a highly researched subject. In this study, crude polysaccharides from spent mushroom substrate of Agrocybe aegerita (AaPs) were extracted for preparing the polysaccharide‑selenium-nanoparticles (AaPs-SeNPs) by ascorbic acid reduction method. The structure of AaPs-SeNPs was analyzed and their growth-promoting effects on rice seedlings were studied by adopting different application methods. The results revealed that AaPs-SeNPs exhibited improved free radical scavenging ability, with a lower half-maximal inhibitory concentrations compared to AaPs. Rice seedlings treated with AaPs-SeNPs showed significant enhancements in growth characteristics when compared to AaPs treatment, and foliar application exhibited a better growth-promoting effect compared to root application. Moreover, the growth performance and antioxidant enzyme activities of rice seedlings were enhanced by the addition of AaPs-SeNPs, and the absorption efficiency of essential nutrients such as N/P/K and Fe/Zn/Mn was also improved at appropriate concentrations, which could be one of the key factors contributing to the improved growth performance of plants. This study provides new aspects for the utilization of SMS, and also offers new insights from the perspective of nutrient absorption on how polysaccharide-conjugated selenium nanoparticles enhance crop growth.

Engineered Selenium/Human Serum Albumin Nanoparticles for Efficient Targeted Treatment of Parkinson's Disease via Oral Gavage

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of dopamine (DA) neurons in the midbrain substantia nigra pars compacta (SNpc). While existing therapeutic strategies can alleviate PD symptoms, they cannot inhibit DA neuron loss. Herein, a tailor-made human serum albumin (HSA)-based selenium nanosystem (HSA/Se nanoparticles, HSA/Se NPs) to treat PD that can overcome the intestinal epithelial barrier (IEB) and blood-brain barrier (BBB) is described. HSA, a transporter for drug delivery, has superior biological characteristics that make it an ideal potential drug delivery substance. Findings reveal that HSA/Se NPs have lower toxicity and higher efficacy than other selenium species and the ability to overcome the IEB and BBB to enrich DA neurons, which then protect MN9D cells from MPP+-induced neurotoxicity and ameliorate both behavioral deficits and DA neuronal death in MPTP-model mice. Thus, a therapeutic drug delivery system composed of orally gavaged HSA/Se NPs for the treatment of PD is described.

Impact of foliar spray with Se, nano-Se and sodium sulfate on growth, yield and metabolic activities of red kidney bean

Sulfur (S) is an essential microelement for plants. Based on the chemical similarity between Se and S, selenium may affects sulphur uptake by plants. This work aimed at investigating the effect of foliar spray with sodium selenate, gum arabic coated selenium nanoparticles (GA-SeNPs ≈ 48.22 nm) and sodium sulfate on red kidney bean (Phaseolus vulgaris L.) plants. Each treatment was used at 0.0, 1, 5, 10 and 50 µM, alone or combination of sodium sulfate with either Se or nano-Se, each at 0.5, 2.5 and 5 µM concentrations. The effect of foliar spray on vegetative growth, seed quality, and some metabolic constituents of red kidney bean (Phaseolus vulgaris L.) plants were investigated. Selenium nanoparticles have been synthesized through the green route using gum arabic (as a stabilizing and coating agent. Foliar application of different concentrations of Se, nano-Se, Na2SO4 up to 10 μM and their interaction were effective in increasing the growth criteria (i.e. shoot and root lengths, plant fresh and dry weights, number of leaves and photosynthetic area (cm2 plant-1).There was also a significant increase in photosynthetic pigment contents, yield (i.e., 100-seed weight), total carbohydrate, crude proteins and mineral contents in both leaf as compared to their untreated control plants. Furthermore, interaction between sodium sulfate with nano-Se or Se, each at 5 µM significantly increased the vegetative growth, 100-seed weight, and pigment contents in leaves and improved the nutritional value and quality of red kidney bean seeds.

Comparison of Nutritional Availability of Biogenic Selenium Nanoparticles and Chemically Synthesized Selenium Nanoparticles

Selenium (Se) is an essential micronutrient, and animals biosynthesize selenoproteins from various selenocompounds such as inorganic salts and organic selenocompounds as a Se source. In addition to the inorganic and organic forms of Se, it is also known that elemental Se is biologically synthesized at the nanoscale in nature. Biologically synthesized Se nanoparticles (Se-NPs), i.e., biogenic Se-NPs (Se-BgNPs), have not been fully investigated as a Se source compared with the other forms of Se. In this study, we evaluated the nutritional availability of Se-BgNPs biosynthesized in E. coli and revealed that Se-BgNPs were less assimilated into selenoproteins in rats as a Se source than inorganic Se salt or chemically synthesized Se-NPs. Se-BgNPs showed tolerance toward digestion and low absorbability in gut, which resulted in the low nutritional availability. Se-BgNPs seem to be coated with a biomaterial that functions to reduce their toxicity toward E. coli and at the same time lowers their availability to animals.

A new application of nano-selenium: rescue of CK2 and mitochondria from oxidative stress to prevent cardiac hypertrophy

Background: Excessive reactive oxygen species (ROS) and subsequent mitochondrial dysfunction are pivotal in initiating cardiac hypertrophy. To explore nano-selenium's (SeNP's) preventive potential against this condition, the authors evaluated chemically synthesized chitosan-SeNPs and biosynthesized Bacillus cereus YC-3-SeNPs in an angiotensin II (Ang II)-induced cardiac hypertrophy model. Methods: This investigation encompassed ROS measurement, mitochondrial membrane potential analysis, transmission electron microscopy, gene and protein expression analyses, protein carbonylation assays, serum antioxidant quantification and histological staining. Results: SeNPs effectively countered Ang II-induced cardiac hypertrophy by reducing ROS, restoring mitochondrial and protein kinase 2α (CK2-α) function, activating antioxidant pathways and enhancing serum antioxidant levels. Conclusion: This finding underscores SeNPs' role in attenuating Ang II-induced myocardial hypertrophy both in vitro and in vivo.

Effect of biosynthesized nanoselenium using Azadirachta indica (Meliaceae) leaf extracts against Eimeria papillata infection

Coccidiosis is a protozoan parasitic disease affecting different animal species. Resistance has been reported for all available anticoccidial drugs. Recently, green synthesis of nanoparticles is considered a new therapeutic tool against this parasitic disease. The present work aimed to study the effect of biosynthesized nanoselenium from Azadirachta indica leaf extracts (BNS) against Eimeria papillata-induced infection in mice. The phytochemical analysis of leaf extracts contained 33 phytochemical components. The BNS was spherical with ⁓68.12 nm in diameter and an absorption peak at 308 nm via UV-spectra. The data showed that mice infected with E. papillata revealed the highest oocyst output on the 5th-day post-infection (p.i.). Infection also induced injury and inflammation of the mice jejunum. Treatment with BNS resulted in a 97.21% suppression for the oocyst output. The treated groups with BNS showed enhancement in feed intake as compared to the infected group. Histological examinations showed a significant reduction in the intracellular developmental Eimeria stages in the jejunal tissues of infected-treated mice of about 24.86 ± 2.38 stages/10 villous crypt units. Moreover, there was a significant change in the morphometry for Eimeria stages after the treatment with BNS. Infection induced a disturbance in the level of carbohydrates and protein contents in the infected mice which enhanced after treatment with BNS. In addition, BNS counteracted the E. papillata-induced loss of the total antioxidant capacity. Collectively, BNS is considered a promising anticoccidial and antioxidant effector and could be used for the treatment of coccidiosis.

Selenium nanoparticles: Properties, preparation methods, and therapeutic applications

Selenium nanoparticles (SeNPs) are a unique type of nano-sized elemental selenium that have recently found wide application in biomedicine. It has been shown that the properties of SeNPs can be varied by different fabrication methods. Moreover, SeNPs have various therapeutic effects in medical applications due to their excellent biological and adaptable physical properties. At the same time, SeNPs can be used as a carrier medium for various therapeutic substances, which can bring out the full curative effects of the drugs. In this review, the differences in bioactivity properties of SeNPs prepared from different substances were reviewed; the therapeutic effects and mechanisms of SeNPs in cancer, inflammation, neurodegenerative diseases, diabetes, reproductive diseases, cardiovascular diseases, and other diseases were discussed; and the importance of the development of SeNPs was further emphasized.

Stabilization of Antioxidant and Anti-Inflammatory Activities of Nano-Selenium Using Anoectochilus burmannicus Extract as a Potential Novel Functional Ingredient

Anoectochilus burmannicus is an orchid that contains phenolic compounds and exhibits antioxidant and anti-inflammation properties. This study aimed to investigate whether its ethanolic extract (ABE) can be used as a reducing agent and/or a stabilizer of nano-selenium (SeNP) synthesis. SeNPs exhibited higher antioxidant activity than ABE-SeNPs. In contrast, ABE-SeNP (4 µM Se) had greater anti-inflammatory activity in LPS-induced macrophages than SeNPs. Interestingly, ABE acted as a stabilizer for SeNPs by preventing particle aggregation and preserving its antioxidant activity after long-term storage (90 days). Moreover, after the freeze-drying process, ABE-SeNPs could be completely reconstituted to suspension with significantly stable antioxidant and anti-inflammatory activities compared to freshly prepared particles, suggesting the cryoprotectant and/or lyoprotectant role of ABE. The present study shows the potential of ABE as an effective stabilizer for nanoparticles and provides evidence for the development of ABE-SeNPs as a food supplement or novel functional ingredient for health benefits.

Selenium Bio-Nanocomposite Based on Alteromonas macleodii Mo169 Exopolysaccharide: Synthesis, Characterization, and In Vitro Antioxidant Activity

In this study, the novel exopolysaccharide (EPS) produced by the marine bacterium Alteromonas macleodii Mo 169 was used as a stabilizer and capping agent in the preparation of selenium nanoparticles (SeNPs). The synthesized nanoparticles were well dispersed and spherical with an average particle size of 32 nm. The cytotoxicity of the EPS and the EPS/SeNPs bio-nanocomposite was investigated on human keratinocyte (HaCaT) and fibroblast (CCD-1079Sk) cell lines. No cytotoxicity was found for the EPS alone for concentrations up to 1 g L^-1. A cytotoxic effect was only noticed for the bio-nanocomposite at the highest concentrations tested (0.5 and 1 g L^-1). In vitro experiments demonstrated that non-cytotoxic concentrations of the EPS/SeNPs bio-nanocomposite had a significant cellular antioxidant effect on the HaCaT cell line by reducing ROS levels up to 33.8%. These findings demonstrated that the A. macleodii Mo 169 EPS can be efficiently used as a stabilizer and surface coating to produce a SeNP-based bio-nanocomposite with improved antioxidant activity.

Constructing Selenium Nanoparticles with Enhanced Storage Stability and Antioxidant Activities via Conformational Transition of Curdlan

Selenium nanoparticles (SeNPs) are among the emerging selenium supplements because of their high bioactivity and low toxicity. However, bare SeNPs are prone to activity loss caused by aggregation and sedimentation. This study aims to stabilize SeNPs with curdlan (CUR), a polysaccharide, to maintain or even enhance their biological activity. Herein, the stable SeNPs were constructed via the unique conformational transition of CUR induced by alkali-neutralization (AN) pretreatment. The physicochemical properties and structures of the prepared SeNPs were characterized by dynamic light scattering (DLS), UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and free-radical-scavenging activity assays. The results show that most SeNPs are stabilized within the triple helix of CUR that has been pretreated with high-intensity AN treatment. These amorphous, small-sized (average size was 53.6 ± 17.7 nm), and stabilized SeNPs have significantly enhanced free-radical-scavenging ability compared to the control and can be well-stabilized for at least 240 days at 4 °C. This work indicates that CUR, as a food additive, can be used to well-stabilize SeNPs by AN pretreatment and provides a facile method to prepare and enhance the stability and bioactivity of SeNPs via triple-helix conformational transition.

The creation of selenium nanoparticles decorated with troxerutin and their ability to adapt to the tumour microenvironment have therapeutic implications for triple-negative breast cancer

The unique use of selenium–troxerutin nanoconjugates as an effective management therapy for treating TNBC.

Ulvan as a Reducing Agent for the Green Synthesis of Silver Nanoparticles: A Novel Mouthwash

The antibacterial activity of an Ulvan-based silver nanoparticle (AgNP) system was evaluated in the current study. The green synthesis of biogenic silver nanoparticles was conducted using Ulvan, a sulphated polysaccharide extracted from Ulva lactuca. A novel mouthwash containing AgNPs was prepared, and tested for its efficacy and safety. AgNPs were confirmed with spectrophotometric analysis (UV–A visible spectrophotometer), and the characterisation was established with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The AgNPs were spherical, and their average size was 8–33 nm, as shown via TEM. The antioxidant assay was conducted via DDPH assay, wherein the AgNPs, at a concentration of 50 μL/mL, showed 93.15% inhibition. Furthermore, anticancer activity was tested by evaluating the cell viability utilising the method of an MTT assay on the 3T3-L1 cell lines. AgNPs, at 30 µL/mL, showed maximal cell viability, denoting no cytotoxic effect. The silver-nanoparticle-based mouthrinse, at a concentration of 100 µL/mL, demonstrated antimicrobial activity against Streptococcus mutans, Staphylococcus aureus, Lactobacillus, and Candida albicans. This study shows that mouthwash prepared from the Ulvan-silver nanoparticle system could be a nontoxic and effective oral antimicrobial agent.

Biogenic Selenium Nanoparticles and Their Anticancer Effects Pertaining to Probiotic Bacteria—A Review

Selenium nanoparticles (SeNPs) can be produced by biogenic, physical, and chemical processes. The physical and chemical processes have hazardous effects. However, biogenic synthesis (by microorganisms) is an eco-friendly and economical technique that is non-toxic to human and animal health. The mechanism for biogenic SeNPs from microorganisms is still not well understood. Over the past two decades, extensive research has been conducted on the nutritional and therapeutic applications of biogenic SeNPs. The research revealed that biogenic SeNPs are considered novel competitors in the pharmaceutical and food industries, as they have been shown to be virtually non-toxic when used in medical practice and as dietary supplements and release only trace amounts of Se ions when ingested. Various pathogenic and probiotic/nonpathogenic bacteria are used for the biogenic synthesis of SeNPs. However, in the case of biosynthesis by pathogenic bacteria, extraction and purification techniques are required for further useful applications of these biogenic SeNPs. This review focuses on the applications of SeNPs (derived from probiotic/nonpathogenic organisms) as promising anticancer agents. This review describes that SeNPs derived from probiotic/nonpathogenic organisms are considered safe for human consumption. These biogenic SeNPs reduce oxidative stress in the human body and have also been shown to be effective against breast, prostate, lung, liver, and colon cancers. This review provides helpful information on the safe use of biogenic SeNPs and their economic importance for dietary and therapeutic purposes, especially as anticancer agents.

Unveiling Antimicrobial and Insecticidal Activities of Biosynthesized Selenium Nanoparticles Using Prickly Pear Peel Waste

In the current study, prickly pear peel waste (PPPW) extract was used for the biosynthesis of selenium nanoparticles through a green and eco-friendly method for the first time. The biosynthesized SeNPs were characterized using UV-Vis, XRD, FTIR, TEM, SEM, EDX, and mapping. Characterization results revealed that biosynthesized SeNPs were spherical, polydisperse, highly crystalline, and had sizes in the range of 10–87.4 nm. Antibacterial, antifungal, and insecticidal activities of biosynthesized SeNPs were evaluated. Results revealed that SeNPs exhibited promising antibacterial against Gram negative (E. coli and P. aeruginosa) and Gram positive (B. subtilis and S. aureus) bacteria where MICs were 125, 125, 62.5, and 15.62 µg/mL, respectively. Moreover, SeNPs showed potential antifungal activity toward Candida albicans and Cryptococcus neoformans where MICs were 3.9 and 7.81 µg/mL, respectively. Furthermore, tested crud extract and SeNPs severely induced larvicidal activity for tested mosquitoes with LC50 and LC90 of 219.841, 950.087 mg/L and 75.411, 208.289 mg/L, respectively. The fecundity and hatchability of C. pipiens mosquito were significantly decreased as applied concentrations increased either for the crude or the fabricated SeNPs extracts. In conclusion, the biosynthesized SeNPs using prickly pear peel waste have antibacterial, antifungal, and insecticidal activities, which can be used in biomedical and environmental applications.

Size-Dependent Cytoprotective Effects of Selenium Nanoparticles during Oxygen-Glucose Deprivation in Brain Cortical Cells

It is known that selenium nanoparticles (SeNPs) obtained on their basis have a pleiotropic effect, inducing the process of apoptosis in tumor cells, on the one hand, and protecting healthy tissue cells from death under stress, on the other hand. It has been established that SeNPs protect brain cells from ischemia/reoxygenation through activation of the Ca2+ signaling system of astrocytes and reactive astrogliosis. At the same time, for a number of particles, the limitations of their use, associated with their size, are shown. The use of nanoparticles with a diameter of less than 10 nm leads to their short life-time in the bloodstream and rapid removal by the liver. Nanoparticles larger than 200 nm activate the complement system and are also quickly removed from the blood. The effects of different-sized SeNPs on brain cells have hardly been studied. Using the laser ablation method, we obtained SeNPs of various diameters: 50 nm, 100 nm, and 400 nm. Using fluorescence microscopy, vitality tests, PCR analysis, and immunocytochemistry, it was shown that all three types of the different-sized SeNPs have a cytoprotective effect on brain cortex cells under conditions of oxygen-glucose deprivation (OGD) and reoxygenation (R), suppressing the processes of necrotic death and inhibiting different efficiency processes of apoptosis. All of the studied SeNPs activate the Ca2+ signaling system of astrocytes, while simultaneously inducing different types of Ca2+ signals. SeNPs sized at 50 nm- induce Ca2+ responses of astrocytes in the form of a gradual irreversible increase in the concentration of cytosolic Ca2+ ([Ca2+]i), 100 nm-sized SeNPs induce stable Ca2+ oscillations without increasing the base level of [Ca2+]i, and 400 nm-sized SeNPs cause mixed patterns of Ca2+ signals. Such differences in the level of astrocyte Ca2+ signaling can explain the different cytoprotective efficacy of SeNPs, which is expressed in the expression of protective proteins and the activation of reactive astrogliosis. In terms of the cytoprotective efficiency under OGD/R conditions, different-sized SeNPs can be arranged in descending order: 100 nm-sized > 400 nm-sized > 50 nm-sized.

Synthesis of macromolecular Astragalus polysaccharide-nano selenium complex and the inhibitory effects on HepG2 cells

In the present study, the previously obtained macromolecuar-weight Astragalus polysaccharide (average molecular weight of 1.61 × 10⁶ Da) was used as a stabilizer and dispersing agent for nano-composites preparation by modifying selenium nanoparticles, and then the anti-hepatoma activity on HepG2 cells was investigated as well. Results showed that the nano-composites were obtained under polysaccharide concentration of 2 mg/mL and selenium/polysaccharide mass ratio of 1:15, and exhibited symmetrical spheroid with an average diameter of 62.3 nm, which has a good stability for 35 days at 4 °C. Furthermore, the in vitro anti-hepatoma experiments demonstrated that the composites could significantly inhibit the proliferation of HepG2 cells in a dose-dependent manner, and could induce the morphological changes, arrest the cell cycle in S phase, finally triggering HepG2 cells apoptosis through mitochondrial pathway. These data revealed that the composites had the potential to be a novel therapeutic drug or adjuvant for hepatoma-bearing patient treatments.

The Influence of Synthesis Conditions on the Antioxidant Activity of Selenium Nanoparticles

Selenium nanoparticles (SeNPs) have attracted great attention in recent years due to their unique properties and potential bioactivities. While the production of SeNPs has been long reported, there is little news about the influence of reaction conditions and clean-up procedure on their physical properties (e.g., shape, size) as well as their antioxidant activity. This study takes up this issue. SeNPs were synthesized by two methods using cysteine and ascorbic acid as selenium reductants. The reactions were performed with and without the use of polyvinyl alcohol as a stabilizer. After the synthesis, SeNPs were cleaned using various procedures. The antioxidant properties of the obtained SeNPs were investigated using DPPH and hydroxyl radical scavenging assays. It was found that their antioxidant activity does not always depend only on the nanoparticles size but also on their homogeneity. Moreover, the size and morphology of selenium nanoparticles are controlled by the clean-up step.

Enterococcus spp. Cell-Free Extract: An Abiotic Route for Synthesis of Selenium Nanoparticles (SeNPs), Their Characterisation and Inhibition of Escherichia coli

Selenite (SeO₃²⁻), the most toxic and most reactive selenium (Se) oxyanion, can be reduced to elemental selenium (Se⁰) nanoparticles by a variety of bacteria, including Enterococcus spp. Previously, the orthodox view held that the reduction of SeO₃²⁻ to Se⁰ by a wide range of bacteria was solely accomplished by biological processes; however, recent studies have shown that various bacterial strains secrete metal-reducing metabolites, thereby indirectly catalysing the reduction of these metal species. In the current study, selenium nanoparticles were synthesised from the abiotic reduction of selenite with the use of Enterococcus spp. cell-free extract. Once separated from the cell-free extract, the particles were analysed using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM) and a Zetasizer. The results revealed that the SeNPs were spherical in shape, containing both amorphous and crystalline properties, and the sizes with the highest frequency ranged close to 200 nm. Additionally, the obtained nanoparticles exhibited antimicrobial properties by directly inhibiting the viability of an E. coli bacterial strain. The results demonstrate not only the potential of abiotic production of SeNPs, but also the potential for these particles as microbial inhibitors in medical or similar fields.

Radiation Synthesis of Selenium Nanoparticles Capped with β-Glucan and Its Immunostimulant Activity in Cytoxan-Induced Immunosuppressed Mice

Selenium nanoparticles (SeNPs) with diameters from 64.8 to 110.1 nm were successfully synthesized by γ-irradiation of solutions containing Se⁴⁺ and water-soluble yeast β-glucan. The size and size distribution of SeNPs were analyzed by dynamic light scattering (DLS). Analytical X-ray diffraction (XRD) pattern results confirmed the crystal structure of the Se nanoparticles and Fourier transform infrared (FTIR) spectroscopy revealed that β-glucan could interact with SeNPs through steric (Se…O) linkages leading to a homogeneous and translucent solution state for 60 days without any precipitates. In vivo tests in cytoxan-induced immunosuppressed mice revealed that the daily supplementation of SeNPs/β-glucan at concentrations of 6 mg per kg body weight of tested mice significantly stimulated the generation of cellular immune factors (white blood cells, neutrophil, lymphocyte, B cells, CD4+ cells, CD34+ cells and natural killer cells) and humoral immune indexes (IgM, IgG, TNF-α, IFN-γ and IL-2) in peripheral blood, bone marrow and spleen of the immunosuppressed mice. The obtained results indicated that radiation-synthesized SeNPs/β-glucan may be a candidate for further evaluation as an agent for the prevention of immunosuppression in chemotherapy.

Biosynthesis of Selenium Nanoparticles (via Bacillus subtilis BSN313), and Their Isolation, Characterization, and Bioactivities

Among the trace elements, selenium (Se) has great demand as a health supplement. Compared to its other forms, selenium nanoparticles have minor toxicity, superior reactivity, and excellent bioavailability. The present study was conducted to produce selenium nanoparticles (SeNPs) via a biosynthetic approach using probiotic Bacillus subtilis BSN313 in an economical and easy manner. The BSN313 exhibited a gradual increase in Se reduction and production of SeNPs up to 5-200 µg/mL of its environmental Se. However, the capability was decreased beyond that concentration. The capacity for extracellular SeNP production was evidenced by the emergence of red color, then confirmed by a microscopic approach. Produced SeNPs were purified, freeze-dried, and subsequently characterized systematically using UV-Vis spectroscopy, FTIR, Zetasizer, SEM-EDS, and TEM techniques. SEM-EDS analysis proved the presence of selenium as the foremost constituent of SeNPs. With an average particle size of 530 nm, SeNPs were shown to have a -26.9 (mV) zeta potential and -2.11 µm cm/Vs electrophoretic mobility in water. SeNPs produced during both the 24 and 48 h incubation periods showed good antioxidant activity in terms of DPPH and ABST scavenging action at a concentration of 150 µg/mL with no significant differences (p > 0.05). Moreover, 200 µg/mL of SeNPs showed antibacterial reactivity against Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 9027, and Pseudomonas aeruginosa ATCC 25923. In the future, this work will be helpful to produce biogenic SeNPs using probiotic Bacillus subtilis BSN313 as biofactories, with the potential for safe use in biomedical and nutritional applications.

Magnetic properties of biogenic selenium nanomaterials

Bioreduction of selenium oxyanions to elemental selenium is ubiquitous; elucidating the properties of this biogenic elemental selenium (BioSe) is thus important to understand its environmental fate. In this study, the magnetic properties of biogenic elemental selenium nanospheres (BioSe-Nanospheres) and nanorods (BioSe-Nanorods) obtained via the reduction of selenium(IV) using anaerobic granular sludge taken from an upflow anaerobic sludge blanket (UASB) reactor treating paper and pulp wastewater were investigated. The study indicated that the BioSe nanomaterials have a strong paramagnetic contribution with some ferromagnetic component due to the incorporation of Fe(III) (high-spin and low-spin species) as indicated by electron paramagnetic resonance (EPR). The paramagnetism did not saturate up to 50,000 Oe at 5 K, and the hysteresis curve showed the coercivity of 100 Oe and magnetic moment saturation around 10 emu. X-ray photoelectron spectroscopy (XPS) and EPR evidenced the presence of Fe(III) in the nanomaterial. Signals for Fe(II) were observed neither in EPR nor in XPS ruling out its presence in the BioSe nanoparticles. Fe(III) being abundantly present in the sludge likely got entrapped in the extracellular polymeric substances (EPS) coating the biogenic nanomaterials. The presence of Fe(III) in BioSe nanomaterial increases the mobility of Fe(III) and may have an effect on phytoplankton growth in the environment. Furthermore, as supported by the literature, there is a potential to exploit the magnetic properties of BioSe nanomaterials in drug delivery systems as well as in space refrigeration.

Preparation and growth-promoting effect of selenium nanoparticles capped by polysaccharide-protein complexes on tilapia

BACKGROUND

Compared with traditional inorganic and organic selenium compounds, nano-selenium exhibited higher biological safety and nutritional potency. However, the biological efficacy of nano-selenium has not been comprehensively and accurately evaluated due to its dispersion instability.

RESULTS

In this study, novel selenium nanoparticles (SeNPs) with high dispersion stability were successfully prepared using a polysaccharide-protein complex (PSP) as the capping agent. This was isolated from abalone viscera. The average particle size and zeta potential of polysaccharide-protein complex selenium nanoparticles (PSP-SeNPs) were 63.33 nm, and -37.1 mV, respectively. The SeNPs were firmly capped by PSP through SeO and SeN bonds, as demonstrated by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. Due to this capping, the dispersion of PSP-SeNPs remained stable for 12 months at 4 °C, as evidenced by visual inspection and multiple light scattering. Furthermore, PSP-SeNPs imparted an excellent growth-promoting effect on tilapia. The FBW, WGR, and SGR values of tilapia juveniles fed with PSP-SeNPs supplemented diets (0.5-4.5 mg/kg) were significantly higher than those of the control (P < 0.05). A weight gain rate of 4.1%-43.4% and specific growth rate of 0.15%-1.74% were obtained in tilapia during 45-day feeding.

CONCLUSIONS

The use of marine viscera polysaccharides is a promising, green method for the synthesis of selenium nanoparticles. There are good opportunities for the application of the synthesized PSP-SeNPs in the life sciences. © 2020 Society of Chemical Industry.

Functional biocompatible nanocomposite films consisting of selenium and zinc oxide nanoparticles embedded in gelatin/cellulose nanofiber matrices

In recent decades, environmental concerns and increasing consumer demand for healthy and nutritious food products with prolonged shelf life have made the food packaging industry pay more attention to the preparation of multifunctional biodegradable packaging films based on biopolymers containing active components such as antioxidant and antimicrobial agents. In this study, bio-nanocomposite films were fabricated from gelatin (G) and cellulose nanofibers (CNFs), and different concentrations of zinc oxide (ZnO) and/or Selenium (Se) nanoparticles (NPs) by the casting method. The mechanical, barrier, optical, and structural (FTIR, XRD, and SEM) properties of the films were investigated along with their antibacterial and antioxidant features. The incorporation of ZnO and Se NPs improved the physicomechanical and water resistance of G/CNF films. In this regard, the maximum tensile strength value was obtained for the G/CNF containing 5% w/w ZnO NPs (G/CNF/ZnO3) and G/CNF containing 0.1% w/w Se NPs (G/CNF/Se2) films (~2.20-fold and ~2.13-fold higher than the G/CNF film, respectively). Also, G/CNF with 3% w/w ZnO NPs (G/CNF/ZnO₂) film had the lowest water vapor permeability and water solubility among all films. Results of the disc diffusion assay showed a stronger antibacterial effect of ZnO NPs compared with Se NPs. The bacterial susceptibility to the antibacterial films was as follows: Listeria monocytogenes > Escherichia coli > Staphylococcus aureus > Pseudomonas fluorescens. The G/CNF films incorporated with Se nanoparticles possessed the higher property of scavenging free radicals in comparison films containing ZnO nanoparticles. Also, the combination of Se NPs and ZnO NPs enhanced the antioxidant effect of the films. In conclusion, gelatin-based edible films containing CNFs, ZnO NPs, and Se NPs can be used in the development of active food packaging products.

Phytoglycogen Nanoparticle Delivery System for Inorganic Selenium Reduces Cytotoxicity without Impairing Selenium Bioavailability

Purpose

Selenium is an essential trace element that supports animal health through the antioxidant defense system by protecting cells from oxidative-related damage. Using inorganic selenium species, such as sodium selenite (Na Sel), as a food supplement is cost-effective; however, its limitation as a nutritional supplement is its cytotoxicity. One strategy to mitigate this problem is by delivering inorganic selenium using a nanoparticle delivery system (SeNP).

Methods

Rainbow trout intestinal epithelial cells, bovine turbinate cells and bovine intestinal myofibroblasts were treated with soluble Na Sel or SeNPs. Two SeNP formulations were tested; SeNP-Ionic where inorganic selenium was ionically bound to cationic phytoglycogen (PhG) NPs, and SeNP-Covalent, where inorganic selenium was covalently bound to PhG NPs. Selenium-induced cytotoxicity along with selenium bioavailability were measured.

Results

SeNPs (SeNP-Ionic or SeNP-Covalent) substantially reduced cytotoxicity in all cell types examined compared to similar doses of soluble inorganic selenium. The SeNP formulations did not affect selenium bioavailability, as selenium-induced glutathione peroxidase (GPx) activity and GPx1 transcript levels were similarly elevated whether cells were treated with soluble Na Sel or SeNPs. This was the case for all three cell types tested.

Conclusion

Nanoparticle-assisted inorganic selenium delivery, which demonstrated equal bioavailability without causing deleterious cytotoxic side effects, has potential applications for safely supplementing animal diets with inorganic selenium at what are usually toxic doses.

In Vitro Assessment Antiparasitic Effect of Selenium and Copper Nanoparticles on Giardia deodenalis Cyst

Background:

Application of chemotherapy to treatment of parasitic disease of man and animals can be problematic due to different adverse effects. As a result, there is an increasing interest in nanoparticles as new therapeutic tools against these diseases. This study was designed to evaluate the effect of selenium and copper oxide nanoparticles on Giardia deudenalis cysts in vitro, as well as comparing it to that of metronidazole.

Methods:

The cysts were taken from the stools of patients in Urmia, Iran, during 2017–2018. The cysts were taken from stool and were concentrated and isolated on 0.85 M-sucrose. Then, selenium and copper oxide nanoparticles were prepared at concentrations of 0.15, 0.3, and 0.6 mg/ml. The effect of nanoparticle’s various concentrations at 10, 15, 30, 60, and 180 min were evaluated and compared to control groups. Obtained data was recorded and statistically analyzed.

Results:

Copper oxide nanoparticles at a concentration of 0.6 mg/ml and selenium nanoparticles at a concentration of 0.3 mg/ml had the same effect as of metronidazole in killing of Giardia cysts. The cytotoxic effects of selenium and copper oxide nanoparticles, compared with metronidazole, on Giardia cysts, showed an increase of fatality rate due to extend exposure time and nanoparticle’s concentration (P<0.05).

Conclusion:

Selenium and copper oxide nanoparticles are as efficient as metronidazole, for killing Giardia cysts in vitro.

Algal biomass as a source for novel oral nano-antimicrobial agent

In the present study, sulphated polysaccharide Ulvan from Ulva lactuca was used for the synthesis of biogenic Selenium Nanoparticles (SeNPs) conjugate and Mouth rinse was prepared using this conjugate. The synthesis of nanoparticles was confirmed by UV–Visible spectrophotometry and characterized using Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and X-ray diffraction (XRD). TEM showed that the average size of the nanoparticle was 85 nm and spherical in shape. Furthermore, nanoparticle conjugates were evaluated for cell viability using MTT assay 3T3-L1 cell line and at 30 µl/ml showed 34% cell viability. The antimicrobial activity of SeNPs mouth rinse was tested against oral pathogens such as Streptococcus mutans, Staphylococcus aureus, Lactobacillus, and Candida albicans and it was effective against all tested microorganism at the concentration of 100 µl/ml. The present study has shown that Ulvan from algal biomass can be a safe and effective source for the development of oral nano-antimicrobial agents.

Leaf Extract of Dillenia indica as a Source of Selenium Nanoparticles with Larvicidal and Antimicrobial Potential toward Vector Mosquitoes and Pathogenic Microbes

Chikungunya, dengue, Zika, malaria, Japanese encephalitis, filariasis, West Nile, etc. are mosquito transmitted diseases that have killed millions of people worldwide, and millions of people are at risk of these diseases. Control of the mosquitoes, such as Aedes aegypti and Culex quinquefasciatus, is challenging due to their development of resistance to synthetic insecticides. The habitats of the young mosquitoes are also the habitats for foodborne pathogens like Staphylococcus aureus (MTCC96) and Serratia marcescens (MTCC4822). The present study was aimed at synthesizing eco-friendly green nanoparticles using Dillenia indica leaf broth and analyzing its efficacy in controlling the vector mosquitoes A. aegypti and C. quinquefasciatus, as well as the microbial pathogens St. aureus and Se. marcescens. The formation of selenium nanoparticles (SeNps) was confirmed using UV-Vis spectroscopy (absorption peak at 383.00 nm), Fourier transform infrared radiation (FTIR spectrum peaks at 3177, 2114, 1614, 1502, 1340, 1097, 901, 705, and 508 cm−1), X-ray diffraction (diffraction peaks at 23.3 (100), 29.6 (101), 43.5 (012), and 50.05 (201)), and scanning electron microscopy (oval shaped). The size of the nanoparticles and their stability were analyzed using dynamic light scattering (Z-Average value of 248.0 nm) and zeta potential (−13.2 mV). The SeNps disorganized the epithelial layers and have broken the peritrophic membrane. Histopathological changes were also observed in the midgut and caeca regions of the SeNPs treated A. aegypti and C. quinquefasciatus larvae. The SeNps were also active on both the bacterial species showing strong inhibitory zones. The present results will explain the ability of SeNps in controlling the mosquitoes as well as the bacteria and will contribute to the development of multi potent eco-friendly compounds.

Selenium Nanoparticles-Embedded Chitosan Microspheres and Their Effects Upon Alcohol-Induced Gastric Mucosal Injury in Rats: Rapid Preparation, Oral Delivery, and Gastroprotective Potential of Selenium Nanoparticles

Background

Selenium (Se) is an indispensable trace element required for animals and human beings, whereas Se-deficiency can accelerate the development of acute gastric injury induced by over-consumption of alcohol. Selenium nanoparticles (SeNPs), as a special Se-supplement with favorable properties and unique bioactivities, are expected to play a passive role in gastroprotection. To the best of our knowledge, the gastroprotective potential of SeNPs is unknown and also, a rapid preparation of orally stable SeNPs available for prospective commercial application in the clinic is needed. Thus, SeNPs-embedded chitosan microspheres (SeNPs-CM) were developed to deliver SeNPs, and their gastroprotective potential was evaluated.

Results

Herein, a rapid, eco-friendly and economic preparation process, composed of synthesis of SeNPs decorated by chitosan (CS), purification of CS-SeNPs by ultra-filtration (UF) and spray-drying of the purified CS-SeNPs, was introduced to prepare SeNPs-CM. The uniformly distributed SeNPs with a nanosize range of 60 nm were loaded into CS-microspheres, and they could be released from the microspheres in gastric conditions. In addition, SeNPs-CM were safer than selenite in terms of Se dose, with a LD₅₀ of around 8-fold of that of selenite, and it could efficiently enhance the Se retention in Se-deficient Wistar rats. Furthermore, SeNPs-CM pre-treatment might significantly attenuate the ethanol-induced gastric mucosal damage, based on histological evaluation. It might be partly attributed to the systematic antioxidant activities of SeNPs-CM, reflected by the reduction in lipid peroxidation, the augmentation in antioxidant enzymatic activity as well as decreasing aggressive nitric oxides (NO).

Conclusion

SeNPs-CM could be taken into consideration as a prospective Se-supplement for the oral delivery of SeNPs, with prominent gastroprotective effect against ethanol-induced mucosal injury.

Engineering highly effective antimicrobial selenium nanoparticles through control of particle size

The overuse of antibiotics has induced the rapid development of antibiotic resistance in bacteria. As a result, antibiotic efficacy has become limited, and infection with multidrug-resistant bacteria is considered to be one of the largest global human health threats. Consequently, new, effective and safe antimicrobial agents need to be developed urgently. One promising candidate to address this requirement is selenium nanoparticles (Se NPs), which are made from the essential dietary trace element Se and have antimicrobial activity against Gram-positive bacteria. The size of nanomaterials can strongly affect their biophysical properties and functions; however, the effects of the size of Se NPs on their antibacterial efficacy has not been systematically investigated. Therefore, in this work, spherical Se NPs ranging from 43 to 205 nm in diameter were fabricated, and their mammalian cytotoxicity and antibacterial activity as a function of their size were systematically studied. The antibacterial activity of the Se NPs was shown to be strongly size dependent, with 81 nm Se NPs showing the maximal growth inhibition and killing effect of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA). The Se NPs were shown to have multi-modal mechanisms of action that depended on their size, including depleting internal ATP, inducing ROS production, and disrupting membrane potential. All the Se NPs were non-toxic towards mammalian cells up to 25 μg mL-1. Furthermore, the MIC value for the 81 nm particles produced in this research is 16 ± 7 μg mL-1, significantly lower than previously reported MIC values for Se NPs. This data illustrates that Se NP size is a facile yet critical and previously underappreciated parameter that can be tailored for maximal antimicrobial efficacy. We have identified that using Se NPs with a size of 81 nm and concentration of 10 μg mL-1 shows promise as a safe and efficient way to kill S. aureus without damaging mammalian cells.

Construction of arabinogalactans/selenium nanoparticles composites for enhancement of the antitumor activity

Selenium nanoparticles (SeNPs) were synthesized using arabinogalactans (LAG) as a formation scaffolding and particle stabilizer to investigate their anti-tumor properties. The formation, morphology, size, and in vitro biological activity of LAG-SeNPs were characterized by UV-vis, FT-IR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and cell toxicity assays. SEM and TEM of LAG-SeNPs visualized the individual spherical nanoparticles, while the spectroscopic characterization revealed the modes of interaction which lead to the stable particle properties of the LAG-SeNPs. Cell toxicity assays indicated that the products had significant inhibitory effect on A549, HepG-2 and MCF-7 cells with a dose-dependent effect. The toxicity mechanisms of LAG-SeNPs were further investigated, and assay results revealed that LAG-SeNPs mainly induced cancer cellular apoptosis to promote atrophy and inhibit cell proliferation. The sum of these findings demonstrates the positive effects that a biomass-derived polysaccharide exert upon non-metal/metalloid-based nanoparticles and the ensuing material's viability as treatment against human cancers.

Effect of Selenium Nanoparticle Supplementation on Tissue Inflammation, Blood Cell Count, and IGF-1 Levels in Spinal Cord Injury-Induced Rats

Selenium is known to be a neuroprotective agent in respect to a number of neuronal diseases and pain. The aim of this study was to evaluate the neuroprotective effect of the oral administration of selenium nanoparticles in rats with spinal cord injury (SCI). Forty adult female rats were randomly assigned to two equal groups as experimental and control. Under general inhalation anesthesia, in both groups, SCI was created, at the T9-10 level of the column. On the third day after the operation, a supplement of selenium nanoparticle was administered to the experimental group at 0.2 mg/kg per day. The histology of the site of injury, IGF-1 serum concentrations, and changes in the white blood cells were examined in both groups at different pre-surgical and post-surgical times. The results of the current study showed a significant decrease in the total white blood cells, including lymphocyte, neutrophil, and monocyte in the experimental group compared to the control group. Histological evaluation showed that the inflammatory responses reduced significantly in the experimental group compared to the control group. In conclusion, we speculate that the decrease in the number of inflammatory cells after oral administration of the selenium nanoparticles is due to the neuroprotective effects of this nanoparticle.

Selenium Nanoparticles Induce the Chemo-Sensitivity of Fluorouracil Nanoparticles in Breast and Colon Cancer Cells

Drug resistance is a major challenge of breast and colon cancer therapies leading to treatment failure. The main objective of the current study is to investigate whether selenium nanoparticles (nano-Se) can induce the chemo-sensitivity of 5-fluorouracil (FU)-encapsulated poly (D, L-lactide-co-glycolide) nanoparticles (nano-FU) in breast and colon cancer cell lines. Nano-Se and nano-FU were synthesized and characterized, then applied individually or in combination upon MCF7, MDA-MB-231, HCT 116, and Caco-2 cancerous cell lines. Cytotoxicity, cellular glucose uptake, and apoptosis, as well as malondialdehyde (MDA), nitric oxide (NO), and zinc (Zn) levels, were investigated upon the different treatments. We have resulted that nano-FU induced cell death in MCF7 and Caco-2 more effectively than MDA-MB-231 and HCT 116 cell lines. Moreover, nano-FU plus nano-Se potentiate MCF7 and Caco-2 chemo-sensitivity were higher than MDA-MB-231 and HCT 116 cancerous cell lines. It is relevant to note that Se and FU nano-formulations inhibited cancer cell bioenergetics via glucose uptake slight blockage. Furthermore, nano-FU increased the levels of NO and MDA in media over cancer cells, while their combinations with nano-Se rebalance the redox status with Zn increment. We noticed that MCF7 cell line is sensitive, while MDA-MB-231 cell line is resistant to Se and nano-Se. This novel approach could be of great potential to enhance the chemo-sensitivity in breast and colon cancer cells.

Construction, stability, and enhanced antioxidant activity of pectin-decorated selenium nanoparticles

Selenium nanoparticles (SeNPs) as a new replacement source of other Se forms applied in nutritional supplements have been associated with health-related issues. Pectin (PEC) as a well-known food-grade polysaccharide has been considered as a potential soft template for the preparation and stabilization of SeNPs in aqueous medium. In this study, therefore, PEC was used as a stabilizer and dispersing agent to form well-dispersed and stable SeNPs under a simple redox system of selenite and ascorbic acid. Se/PEC ratios significantly affected the color of the suspension, particle size, and surface morphology of the as-prepared SeNPs in the presence of PEC. PEC-SeNPs with a Se/PEC ratio of 1:2 appeared amorphous and exhibited a well-dispersed and stable spherical structure with an average size of ∼41 nm, which corresponds to the strong hydrogen bonding between the hydroxyl groups of PEC and SeNPs. The PEC-SeNPs (Se/PEC = 1:2) remained highly stable in different acidic solutions for at least 1 month. Small and highly stable PEC-SeNPs (Se/PEC = 1:2) possessed the strongest DPPH radical scavenging ability and antioxidant capacity among the evaluated PEC-SeNPs. They also possessed a low cytotoxic activity against cancer cells (SPCA-1 and HeLa) and normal cells (RWPE-1) in vitro. These findings suggested that pectin as a surface decorator could be effectively used to improve the stability and antioxidant capacity of SeNPs remarkably.