Bactericidal Effect of Selenium Nanoparticles Combined with Povidone-iodine on Pathogenic Bacteria in Surgical Site Infection / 中山大学学报(医学科学版)

ObjectiveTo investigate the bactericidal effect of loaded multifunctional povidoneiodine-nanometer selenium （PVP-I@Se） disinfectant on Staphylococcus aureus （SA） and methicillin-resistant Staphylococcus aureus （MRSA）， and to provide an experimental basis for the reduction of surgical site infection （SSI）. MethodsThe control group was the povidone iodine （PVP-I） group with different concentrations of iodine （50， 75， 100， 200 and 400 μg/mL）. The PVP-I@Se group （experimental group） was the PVP-I group further supplemented with 2 μg/mL Selenium nanoparticles （SeNPs）. Then we compared the bactericidal effect of the two groups of disinfectant solutions on SA and MRSA by examining the minimum inhibitory concentration （MIC）， minimum bactericidal concentration （MBC）， the shortest sterilization time at a concentration of 50 μg/mL iodine and the inhibition zone diameters at concentrations of 200 μg/mL and 400 μg/mL iodine. ResultsMIC values of PVP-I against SA and MRSA were both 79.17 μg/mL， and those of PVP-I@Se were 54.17 and 70.83 μg/mL， respectively. MBC values of PVP-I against SA and MRSA were 129.17 and 150.00 μg/mL， respectively， and those of PVP-I@Se were 70.83 and 87.50 μg/mL， respectively. At a concentration of 50 μg/mL iodine， the shortest sterilization time of PVP-I for SA and MRSA was 130 s and 140 s， respectively， and that of PVP-I@Se was 65 s and 75 s， respectively. At a concentration of 200 μg/ml iodine， the inhibition zone diameters of PVP-I for SA and MRSA were 7.67 mm and 8.33 mm， and those of PVP-I@Se were both 9.50 mm. At a concentration of 400 μg/mL iodine， the inhibition zone diameters of PVP-I for SA and MRSA were 9.00 mm and 9.33 mm， and those of PVP-I@Se were 11.67 mm and 12.00 mm， respectively. ConclusionsPVP-I with different concentrations of 50， 75， 100， 200 and 400 μg/mL iodine supplemented with 2 μg/mL SeNPs have better and faster bactericidal effect on SA and MRSA. When combined with SeNPs， PVP-I can enhance the bactericidal activity against SA and MRSA， but with better sensitizing effect on SA than MRSA and higher demand of iodine concentration （400 μg/mL） for sensitizing effect on MRSA. This study provides a theoretical basis for selecting optimal concentration and action time of the disinfectant， thus reducing SSI.

Research progress on synthesis, safety, function and mechanism of selenium nanoparticles / 中国药理学通报

As an essential trace element, selenium plays a very important role in antioxidation and maintaining redox homeostasis in various metabolic processes. With the development of nano-technology, selenium nanoparticles ( SeNPs) have become potential biomedical drugs because of their low toxicity, degrad-ability and high bioavailability. With the ability to activate apop-tosis or autophagy by regulating the production of reactive oxygen species ( ROS) , SeNPs are widely used in anticancer therapy and pathogens killing/clearance. In addition, with excellent stability and drug encapsulation capacity, SeNPs are serving as a kind of effective nano-carriers for anti-cancer and anti-infection treatments. Interestingly, the important role of SeNPs in immune regulation ( such as the activation of macrophages and T effector cells) provides a new possibilities to achieve nano-immune syn-ergetic treatment strategy for anti-cancer and anti-infection thera¬pies. In this paper, we review the latest progress of the prepara¬tion methods and safety for SeNPs, followed by the advances of anti-infection, anti-cancer effects and its mechanisms, which would be helpful for promoting the pace of clinical research and application. In addition, we also summarize the functions of SeNPs in other aspects, so as to provide beneficial assistance for facilitating its scientific and clinical research.

Green-synthetized selenium nanoparticles using berberine as a promising anticancer agent / 中西医结合学报

OBJECTIVE@#The chemo-preventative and therapeutic properties of selenium nanoparticles (SeNPs) have been documented over recent decades and suggest the potential uses of SeNPs in medicine. Biogenic SeNPs have higher biocompatibility and stability than chemically synthesized nanoparticles, which enhances their medical applications, especially in the field of cancer therapy. This study evaluated the potential of green-synthetized SeNPs by using berberine (Ber) as an antitumor agent and elucidated the mechanism by which these molecules combat Ehrlich solid tumors (ESTs).@*METHODS@#SeNPs containing Ber (SeNPs-Ber) were synthesized using Ber and Na@*RESULTS@#Treatment with SeNPs-Ber significantly improved the survival rate and decreased the body weight and tumor size, compared to the EST group. SeNPs-Ber reduced oxidative stress in tumor tissue, as indicated by a decrease in the lipid peroxidation and nitric oxide levels and an increase in the glutathione levels. Moreover, SeNPs-Ber activated an apoptotic cascade in the tumor cells by downregulating the B-cell lymphoma 2 (Bcl-2) expression rate and upregulating the Bcl-2-associated X protein and caspase-3 expression rates. SeNPs-Ber also considerably improved the histopathological alterations in the developed tumor tissue, compared to the EST group.@*CONCLUSION@#Our study provides a new insight into the potential role of green-synthesized SeNPs by using Ber as a promising anticancer agent, these molecules could be used alone or as supplementary medication during chemotherapy.

Biogenic synthesis of selenium nanoparticles by Shewanella sp. HN-41 using a modified bioelectrochemical system

BACKGROUND Synthesis of selenium nanoparticles from selenite by Shewanella sp. HN-41 demonstrated that particle size depended on the reaction time and biomass of cells. The slow reaction and low biomass tended to form small particles. In this study, Shewanella sp. HN-41 was introduced into the anode of a nonexternal circuit bioelectrochemical system (nec_BES) to convert chemical energy from lactate to low electron current to the cathode, where selenite was reduced. RESULTS Our experiment with two systems, one bioelectrochemical system with a cathode flushed with nitrogen and the other with a no-nitrogen-flushing cathode, showed that the former could not produce Se nanoparticles after 21 d, but the latter formed them with an average size of 37.7 nm. The SEM and TEM images demonstrated that the particle size of 10 nm occupied over 10% and most of the particles were in the range of 30­60 nm. The XRD result and SAED image demonstrated no clear peaks of crystal and proved that the Se nanoparticles are amorphous. CONCLUSIONS : The clean Se nanoparticles were synthesized and completely separated from bacterial cells in the bioelectrochemical system. This study opened a new approach for the biological synthesis of metal nanoparticles. Finally, the Se products in the range of 30­60 nm can be tested for antimicrobial activities in medical applications

Antifungal Activity of Selenium Nanoparticles Extracted from Capparis decidua Fruit against Candida albicans.

Nanotechnology has introduced nanoparticulate form of selenium for a wide variety of applications. Nanoparticles can be used in medicine due to their increased interaction with microbes and also because it has fewer side effects than the drugs. Selenium nanoparticles have unique biomedical applications ranging from antioxidant activity to anticancer activity. It is distinct with its high biological activity and low toxicity and cytotoxic property. Capparis decidua also called as karira belonging to Capparaceae family is a xerophytic small branched shrub found in Africa, Middle East and South Asia. Its fruit is used for preparing curry and pickles in the western parts of India. In our study, the selenium nanoparticles were extracted from its fruit. Candida albicans is pathogenic yeast in the oral cavity, gastrointestinal tract and the urogenital tract affecting the immunocompromised patients and causes various types of infections. It has gained resistance to present antifungals and new formulations are needed to be discovered. MethodsPlant extract was prepared from Capparis decidua fruit powder and filtered using Whatman No. 1 filter paper. It was kept in magnetic stirrer for nanoparticle synthesis. Colour change was observed which indicates the synthesis of nanoparticles. UV visible spectroscopy was taken in proper intervals. The nanoparticles synthesized were purified by centrifugation technique and checked for its antifungal activity. Antifungal activity of the prepared nanoparticles against Candida albicans was determined by using agar well diffusion assay method or agar disc diffusion method. The zone of inhibition formed around the disc indicates the sensitivity of the fungi to the plant extract. The inhibition zone diameter was measured using a ruler and compared with the inhibition zone formed by the positive control drug which was done in parallel. ResultsAntifungal activity was showed by an inhibition zone which was characterized by a clear zone around the wells. The diameter of the inhibition zone formed for 50 mL of the plant extract was 20.33 mm ± 0.47, for 100 mL of the plant extract was 28.33 mm ± 0.47, for 150 mL of the plant extract was 30.33 mm ± 0.47 and for the positive control drug was 34.33 mm ± 0.47. ConclusionsThe diameter of the inhibition zones was compared with the positive control drug. Selenium nanoparticles extracted from Capparis decidua fruit showed high activity against Candida albicans. Further in vivo research can be done for the same and it may represent an alternative for treating fungal infections.

Characteristics of selenium nanoparticles synthesized by cell-free supernatant Cupriavidus sp. SHE / 生物工程学报

In recent years, selenium nanoparticles (SeNPs) have been widely used in many fields such as nanotechnology, biomedicine and environmental remediation due to their good electrical conductivity, photothermal properties and anticancer properties. In this study, the cell-free supernatant, whole cell and the cell-free extracts of the strain Cupriavidus sp. SHE were used to synthesize SeNPs, and several methods were applied to analyze the crystal structure and surface functional groups of the nanoparticles. Finally, Pseudomonas sp. PI1 (G⁺) and Escherichia coli BL21 (G⁻) were selected to investigate the antibacterial properties of SeNPs. Cell-free supernatant, whole cell and cell-free extracts of the strain could synthesize SeNPs. As for the cell-free supernatant, selenite concentration of 5 mmol/L and pH=7 were favorable for the synthesis of SeNPs. TEM images show that the average size of nanospheres synthesized by the supernatant was 196 nm. XRD analysis indicates the hexagonal crystals structure of SeNPs. FTIR and SDS-PAGE confirmed the proteins bound to the surfaces of SeNPs. SeNPs synthesized by cell-free supernatant showed no antimicrobial activities against Pseudomonas sp. PI1 and Escherichia coli BL21 (DE3). These results suggest that proteins played an important role in biotransformation of SeNPs in an eco-friendly process, and SeNPs synthesized in this study were non-toxic and biologically compatible, which might be applied in other fields in the future.

Selenium-layered nanoparticles serving for oral delivery of phytomedicines with hypoglycemic activity to synergistically potentiate the antidiabetic effect

Diabetes mellitus (DM) remains a great challenge in treatment due to pathological complexity. It has been proven that phytomedicines and natural medicines have prominent antidiabetic effects. This work aimed to develop selenium-layered nanoparticles (SeNPs) for oral delivery of mulberry leaf and extracts (MPE), a group of phytomedicines with significant hypoglycemic activities, to achieve a synergic antidiabetic effect. MPE-loaded SeNPs (MPE-SeNPs) were prepared through a solvent diffusion/ reduction technique and characterized by particle size, potential, morphology, entrapment efficiency (EE) and drug loading (DL). The resulting MPE-SeNPs were 120 nm around in particle size with EE of 89.38% for rutin and 90.59% for puerarin, two marker components in MPE. MPE-SeNPs exhibited a slow drug release and good physiological stability in the simulated digestive fluid. After oral administration, MPE-SeNPs produced significant hypoglycemic effects both in the normal and diabetic rats. intestinal imaging and cellular examinations demonstrated that MPE-SeNPs were provided with outstanding intestinal permeability and transepithelial transport aptness. It was also revealed that MPE-SeNPs could alleviate the oxidative stress, improve the pancreatic function, and promote the glucose utilization by adipocytes. Our study provides new insight into the use of integrative nanomedicine containing phytomedicines and selenium for DM treatment.

Effects of selenium nanoparticles and sodium selenite on apoptosis and reactive oxygen species in chondrocytes from articular cartilage in patients with Kashin-Beck disease / 中华地方病学杂志

Objective To compare the effects of selenium nanoparticles (Nano-Se) and sodium selenium (Na2SeO3) on apoptosis and reactive oxygen species (ROS) of articular chondrocytes from patients with Kashin-Beck Disease (KBD) in vitro,and provide a scientific basis for preventing KBD.Methods The subjects with KBD were diagnosed on National Clinical Diagnostic Criteria of KBD (WS/T207-2010),articular cartilage from 8 patients undertaken joint replacement operation were collected.In vitro,chondrocytes were treated with concentration of 0,25,50,100,200,300,400 and 500 μg/L of Nano-Se and Na2SeO3 for 5 d,respectively.Cell growth was detected by MTT assay,and the highest concentration and time corresponding to the highest survival rate of Nano-Se and Na2SeO3 were used in the following experiment.KBD chondrocytes were treated with Nano-Se and Na2SeO3,and divided into control group,Na2SeO3 group,Nano-Se group according to the randomized design.Each group had 8 cases.The cell apoptosis and ROS were detected by flow cytometry.Results The optimal intervention concentration of Nano-Se and Na2SeO3 was 100 and 400 μg/L,respectively.The optimal intervention time of NanoSe and Na2SeO3 both was 3 days.There was a significant decrease in the total and terminal apoptosis,ROS level of chondrocytes in Nano-Se group [(4.67 ± 0.89)％,(1.51 ± 0.48)％,(56.04 ± 4.81)％] and Na2SeO3 group [(7.07 ±0.25)％,(4.37 ± 0.37)％,(87.13 ± 6.60)％] compared with those of control group [(9.95 ± 0.38)％,(6.93 ± 0.42)％,(125.17 ± 16.60)％,all P ＜ 0.01].The difference of early apoptotic rate among control group,Na2SeO3 group,NanoSe group [(3.02 ± 0.41)％,(2.7 ± 0.46)％,(3.16 ± 0.56)％] was not statistically significant (F =2.11,P =0.35).Conclusion Appropriate concentration of Nano-Se can significantly decrease oxidative stress of KBD chondrocytes and inhibit apoptosis compared to Na2SeO3.

Synthesis of Selenium Nanoparticles by Bacillus laterosporus Using Gamma Radiation.

Aim: This study shows the possible synthesis of Selenium Nanoparticles (SeNPs) in aerobic optimized conditions using Bacillus laterosporus (B. laterosporus) bacterial strain. Methodology: B. laterosporus was used to reduce selenium ions (selenite anions) to SeNPs by fermentation in Luria-Bertani Enrichment (EM) medium. Optimization of fermentation conditions using two-level full factorial design was performed. SeNPs were further characterized by UV-Vis., DLS, TEM, FT-IR, EDX and XRD analysis. SeNPs synthesis by Gamma irradiated B. laterosporus cells at different radiation doses was reported. Evaluation the probability of B. laterosporus to synthesis SeNPs by fermentation in skimmed milk aerobically. A microtiterplate assay was used to evaluate the ability of SeNPs to inhibit the biofilm formation of Pseudomonas aeruginosa. Evaluating the antimicrobial activity of some antibiotic agents upon addition of SeNPs was performed. Results: B. laterosporus reduced the soluble, toxic, colorless selenium ions to the insoluble, non-toxic, red elemental SeNPs. Statistical analysis showed that the results were normally distributed. Temperature, incubation period and pH were significant factors in the fermentation process, in which the maximum SeNPs produced (8.37μmole/ml) was at temperature 37ºC, incubation period 48hr, pH7. The Gamma radiation exposure dose 1.5kGy gave the maximum SeNPs produced (10.01 μmole/ml). A pink color appear in the fermented milk revealing the formation of SeNPs-enriched milk. SeNPs inhibit the biofilm formation of Pseudomonas aeruginosa with a percentage reduction of 99.7%. SeNPs increase the antibacterial activity of fucidic acid by 13.6% and 28.5% against Escherichia coli and Staphylococcus aureus respectively. But with Gentamycin sulphate, no change in the antibacterial activity. Conclusion: SeNPs can be synthesized aerobically by the probiotic B. laterosporus bacterial strain. SeNPs can be incorporated in nutraceuticals and functional foods like milk also can be used to inhibit the bacterial biofilm formation and can be added to some antibacterial creams to enhance their antimicrobial activity.

Biosynthesis of selenium nanoparticles using Klebsiella pneumoniae and their recovery by a simple sterilization process

The use of biologically derived metal nanoparticles for various proposes is going to be an issue of considerable importance; thus, appropriate methods should be developed and tested for the biological synthesis and recovery of these nanoparticles from bacterial cells. In this research study, a strain of Klebsiella pneumoniae was tested for its ability to synthesize elemental selenium nanoparticles from selenium chloride. A broth of Klebsiella pneumoniae culture containing selenium nanoparticles was subjected to sterilization at 121ºC and 17 psi for 20 minutes. Released selenium nanoparticles ranged in size from 100 to 550 nm, with an average size of 245 nm. Our study also showed that no chemical changes occurred in selenium nanoparticles during the wet heat sterilization process. Therefore, the wet heat sterilization process can be used successfully to recover elemental selenium from bacterial cells.