Functionalized selenium nanoparticles ameliorated acetaminophen-induced hepatotoxicity through synergistically triggering PKCδ/Nrf2 signaling pathway and inhibiting CYP 2E1

Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications.

In Vivo Studies and Flow Cytometric Investigation on Anticancer Potential of Selenium Nanoparticles Synthesized via Aqueous Extract of Clerodendron phlomidis

Nowadays,doctors and nutritionists recommend individuals incorporate selenium-rich foods such as nuts,cereals,and mushrooms into their regular diet to maintain fitness and overall health.Selenium nanoparticles(SeNPs)exhibit strong chemopreventive capabilities.The anticipations for SeNPs with enhanced and tunable bioactive activities have led to a keen interest in phytofabrication.In this study,the aqueous extract of Clerodendron phlomidis plant leaves was utilized for the synthesis of SeNPs.In traditional Indian medicine,this plant extract is recognized as a significant anti-diabetic agent.The flavonoids tetrahydroxylflavone,7-hydroxyflavanone,and 6,4’-dimethyl-7-acetoxy-scutellarein present in this plant leaf extract demonstrate excellent anticancer activity.These secondary metabolites exhibit the ability to reduce sodium selenite into SeNPs.At a concentration of 13μg/mL,the synthesized SeNPs effectively inhibited the proliferation of the HepG2 cell line.The results suggest that the SeNPs possess promising anti-cancer potential against liver cancer and can be considered as a therapeutic agent for liver cancer treatment.Additionally,the cell cycle arrest induced by SeNPs was further confirmed by the fluorescence-activated cell sorting(FACS)method,indicating that SeNPs could efficiently differentiate cancer cells from normal cells.Notably,it showed a significant improvement in diethylnitrosamine(DEN)-induced Swiss Wistar rat groups.This scientific investigation highlights the high anti-cancer potential of SeNPs,positioning them as a promising therapeutic agent for liver cancer treatment.

Inhibition of H_(2)O_(2)-induced apoptosis of GC2-spg cells by functionalized selenium nanoparticles with lentinan through ROSmediated ERK/p53 signaling pathways

AH_(2)O_(2)-induced oxidative stress injury cell model was established to investigate the antioxidant effect of nanoselenium on mouse spermatocyte lines and the regulation mechanism of the expression level and activity of seleniumcontaining antioxidant enzymes induced by oxidative stress.A safe and effective nano-drug system of functionalized selenium-containing nanoparticles(SeNPs)was developed with lentinan(LNT)(SeNPs@LNT).Mice spermatocyte line GC2-spg cells were treated with SeNPs@LNT(1,2,4,8,16,32μM)for 24-72 h to evaluate the cytotoxicity of selenium.GC2-spg cells were randomly divided into the following groups:control,hydrogen peroxide(H_(2)O_(2)),SeNPs@LNT,and H_(2)O_(2)+SeNPs@LNT groups.H_(2)O_(2)+SeNPs@LNT group was pretreated with SeNPs@LNT 4μM for 12 h,followed by H_(2)O_(2)600μM for 8 h.The cell viability decreased in the H_(2)O_(2) group and increased significantly in the SeNPs@LNT group.Compared with the H_(2)O_(2) group,the SeNPs@LNT+H_(2)O_(2) group exhibited obvious red fluorescence,indicating a higher level of mitochondrial membrane potential.The content of intracellular reactive oxygen species(ROS)in the SeNPs@LNT group reduced significantly,and the intensity of green fluorescence in the SeNPs@LNT+H_(2)O_(2) group decreased significantly compared with the H_(2)O_(2) group,indicating the inhibitory effect of SeNPs@LNT on the generation of ROS-induced oxidative stress.The activity of GPx and SOD increased significantly in the SeNPs@LNT group.The expression of p53 decreased significantly under the intervention of nano-selenium,and GPx1 expression increased.In the oxidative stress group,the expressions of DNA damage-related proteins and apoptosis-related proteins were higher than those in other groups.Thus,SeNPs@LNT can promote GC2-spg cell proliferation,improve GPx and SOD activities,remove intracellular ROS,and reduce mitochondrial damage and functional abnormalities caused by oxidative stress by regulating the ERK and p53 protein levels.SeNPs@LNT has good biological activity and antioxidant effect,which can be used to protect the male reproductive system from oxidative stress.

Inhibition of H_(2)O_(2)-induced TM3 cell apoptosis by oxidative stress by lentinan functionalized selenium nanoparticles through JAK2/STAT-3 and P53 pathways

Background:Nano-selenium has been widely used in antiviral and anticancer therapy,and has the advantages of good targeting and low toxicity.For the first time,we combined male reproduction with nano-selenium to investigate its antioxidant effect.This study investigated the protective effect of lentinan functionalized selenium nanoparticles on oxidative stress injury of the hydrogen peroxide(H_(2)O_(2))-induced Leydig cell line,TM3.Methods:The suitable concentration of nano-selenium treatment to promote cell proliferation was also discussed.The concentration of 4μM could significantly promote the growth of TM3 cells.Oxidative stress damage was caused using an 800μM concentration of hydrogen peroxide.The cells were divided into four groups:normal control group,oxidative stress treatment group,H_(2)O_(2)+SeNPs@LNT group,and SeNPs@LNT group.The H_(2)O_(2)+SeNPs@LNT group was pretreated with 4μM of SeNPs@LNT for 12 h,followed by 800μM of H_(2)O_(2)for 8 h.Results:Nano-selenium could significantly promote the proliferation and viability of TM3 cells.SeNPs@LNT treatment increased the level of mitochondrial membrane potential in normal cells and slowed down the decline in mitochondrial membrane potential level caused by oxidative stress injury.In addition,the increase in reactive oxygen species caused by oxidative stress was inhibited by SeNPs@LNT treatment.The apoptosis of TM3 cells was detected,and SeNPs@LNT alleviated the necrosis and apoptosis of TM3 cells induced by H_(2)O_(2).Nano-selenium plays a protective role against oxidative H_(2)O_(2)-induced stress injury in TM3 cells through the changes in the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway and P53 pathway,and the expression levels of other related proteins,protein kinase B(AKT)and C3.Conclusion:SeNPs@LNT exhibited good biological activity and antioxidant effect and can thus be used to protect the male reproductive system from oxidative stress.

Selenium Nanoparticles Prepared from Reverse Microemulsion Process

Selenium nanoparticles were prepared by a reverse microemulsion system. Sodium selenosulfate was used as selenium source. The results showed that hydrochloric acid concentration and reaction temperature had great influence on the morphology of products. The crystalline selenium nanowires and amorphous selenium nanorods were obtained in given condition.

Testing Toxicity and Antidote Effect of Selenium Nanoparticles with <i>Paramecium caudatum</i>

A simple method for assessment of the toxicity and antidote effect of selenium nanoparticles with Paramecium caudatum is presented. Light microscopy in combination with computerized video tracking is employed for the determination of the survival time of P. caudatum. Up to 800 mg/L, selenium nanoparticles are not acutely toxic. With respect to a potential antidote effect, the lethality of silver nanoparticles, silver nitrate, sodium hydrogen selenite, and sodium selenite to P. caudatum was decreased and survival time was extended upon pre-treatment with selenium nanoparticles. Taken together, these findings suggest that administration of selenium nanoparticles attenuates exposure to toxicants. Selenium nanoparticles could be a good functional additive for food management in animals.

A New Method for the Synthesis of Selenium Nanoparticles and the Application to Construction of H_2O_2 Biosensor

The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.

Designing macrophage membrane-engineered ruthenium/selenium nanoparticles to block bone metastasis of breast cancer

Bone metastasis along with osteolysis is a common complication of advanced breast cancer,which directly destroys bone function and becomes one of the major causes of cancer-related mortality.It is crucial to develop a new strategy to achieve effective cancer therapy and inhibition of osteolytic bone metastasis.Metal ruthenium(Ru)complexes exhibit therapeutic potential in cancer chemotherapy.However,the clinical applications of Ru complexes were limited by poor bioavailability,lacking targeting,nonspecific distribution.Therefore,in this study,engineering of cell membrane biomimetic modification was used to construct a highly biocompatible nanoplatform with carrying Ru metal complex of RuPOP and Se nanoparticles(SeNPs).Strikingly,the obtained RPSR nanoparticles can efficiently inhibit the proliferation,invasion and migration of breast cancer cells(MDA-MB-231 cells)in vitro.More importantly,RPSR nanoparticles can induce cycle arrest,apoptosis by generating excessive intracellular(reactive oxygen species,ROS)to disrupt the normal redox balance and induce DNA damage in tumor cells.Furthermore,RPSR nanoparticles can also reshape bone microenvironment by regulating selenoproteins to inhibit osteoclasts and avoid osteolytic bone metastasis induced by tumor development.Taken together,this study not only provides an effective cell membrane biomimetic strategy to enhance the shortcomings of metal complexes,but also demonstrates potential clinical significance for the combined treatment of anti-cancer and bone metastasis inhibition.

Selenium nanoparticles in aquaculture:Unique advantages in the production of Se-enriched grass carp(Ctenopharyngodon idella)

The production of selenium-enriched fish can contribute to alleviating selenium deficiency in human diets.However,it is still unclear which selenium source,as an additive,can efficiently and costeffectively produce high-quality selenium-enriched fish.This study evaluated the effects of selenium nanoparticles(SeNP),selenite,and selenomethionine(SeMet)on the growth,antioxidant capacity,selenium content,selenium speciation,and meat quality of grass carp.Ten diets were prepared,including a basal diet(BD)and three concentrations(0.1,0.3,and 0.9 mg/kg)of SeNP,selenite,and SeMet.A total of600 fish(250.79±1.57 g)were randomly assigned to 30 tanks(3 tanks/group).Fish were fed the experimental diet three times daily for 60 d.In this study,SeNP most significantly promoted the growth and antioxidant capacity of grass carp,with 0.3 mg/kg SeNP identified as the optimal additive concentration.Additionally,SeNP demonstrated equally excellent bioavailability as SeMet and significantly increased the content of SeMet in grass carp(Ctenopharyngodon idella)muscle.Furthermore,compared to SeMet and selenite,dietary SeNP could more significantly enhance the content of selenocysteine(SeCys2)and methylselenocysteine(MeSeCys)in grass carp muscle tissue.In addition,we have demonstrated that SeCys2and MeSeCys promote apoptosis of cancer cells(HeLa)through the mitochondrial apoptotic pathway(involving Bax and Bcl-2).Furthermore,as an additive,0.3 mg/kg SeNP significantly improved the flesh quality of grass carp by reducing crude fat and heavy metal content,as well as increasing the levels of eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)and the ratio of n-3/n-6 polyunsaturated fatty acid(PUFA).In summary,SeNP is the most suitable additive for producing selenium-enriched fish.

Translational selenium nanoparticles boost GPx1 activation to reverse HAdV-14 virus-induced oxidative damage

Human adenovirus(HAdV)can cause severe respiratory infections in immunocompromised patients,but its clinical treatment is seriously limited by side effects of drugs such as poor efficacy,low bioavailability and severe nephrotoxicity.Trace element selenium(Se)has been found will affect the disease progression of pneumonia,but its antivirus efficacy could be improved by speciation optimization.Therefore,herein we performed anti-HAdV effects of different Se speciation and found that lentinan(LNT)-decorated selenium nanoparticles(SeNPs)exhibited low cytotoxicity and excellent anti-HAdV antiviral activity.Furthermore,SeNPs@LNT reduced the HAdV infection-induced mitochondrial damage and excessive production of reactive oxygen species(ROS).It was also involved in the repair of host cell DNA damage and inhibition of viral DNA replication.SeNPs@LNT inhibited HAdV-induced apoptosis mainly by modulating the p53/Bcl-2 apoptosis signaling pathway.In vivo,SeNPs@LNT replenished Se by targeting the infected site through the circulatory system and was involved in the synthesis of Glutathione peroxidase 1(GPx1).More importantly,GPx1 played an antioxidant and immunomodulatory role in alleviating HAdV-induced inflammatory cytokine storm and alleviating adenovirus pneumonia in Se-deficient mice.Collectively,this study provides a Se speciation of SeNPs@LNT with anti-HAdV activity,and demonstrate that SeNPs@LNT is a promising pharmaceutical candidate for the treatment of HAdV.

Aggregation and stability of selenium nanoparticles: Complex roles of surface coating, electrolytes and natural organic matter

The application of selenium nanoparticles(SeNPs)as nanofertilizers may lead to the release of SeNPs into aquatic systems.However,the environmental behavior of SeNPs is rarely studied.In this study,using alginate-coated SeNPs(Alg-SeNPs)and polyvinyl alcohol-coated SeNPs(PVA-SeNPs)as models,we systematically investigated the aggregation and stability of SeNPs under various water conditions.PVA-SeNPs were highly stable in mono-and polyvalent electrolytes,probably due to the strong steric hindrance of the capping agent.Alg-SeNPs only suffered from a limited increase in size,even at 2500 mmol/L NaCl and 200 mmol/L MgCl_(2),while they underwent apparent aggregation in CaCl_(2) and LaCl_(3) solutions.The binding of Ca^(2+) and La^(3+) with the guluronic acid part in alginate induced the formation of cross-linking aggregates.Natural organic matter enhanced the stability of Alg-SeNPs in monovalent electrolytes,while accelerated the attachment of Alg-SeNPs in polyvalent electrolytes,due to the cation bridge effects.The long-term stability of SeNPs in natural water showed that the aggregation sizes of Alg-SeNPs and PVA-SeNPs increased to several hundreds of nanometers or above 10μm after 30 days,implying that SeNPs may be suspended in the water column or further settle down,depending on the surrounding water chemistry.The study may contribute to the deep insight into the fate and mobility of SeNPs in the aquatic environment.The varying fate of SeNPs in different natural waters also suggests that the risks of SeNPs to organisms living in diverse depths in the aquatic compartment should be concerned.

Replacing dietary sodium selenite with biogenic selenium nanoparticles improves the growth performance and gut health of early-weaned piglets

Selenium nanoparticles(SeNPs)are proposed as a safer and more effective selenium delivery system than sodium selenite(Na_(2)SeO_(3)).Here,we investigated the effects of replacing dietary Na_(2)SeO_(3)with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of earlyweaned piglets.Seventy-two piglets(Duroc×Landrace×Large Yorkshire)weaned at 21 d of age were divided into the control group(basal diet containing 0.3 mg Se/kg from Na_(2)SeO_(3))and SeNPs group(basal diet containing 0.3 mg Se/kg from SeNPs)during a 14-d feeding period.The results revealed that SeNPs supplementation increased the average daily gain(P=0.022)and average daily feed intake(P=0.033),reduced(P=0.056)the diarrhea incidence,and improved(P=0.013)the feed conversion ratio compared with Na_(2)SeO_(3).Additionally,SeNPs increased jejunal microvilli height(P=0.006)and alleviated the intestinal barrier dysfunction by upregulating(P<0.05)the expression levels of mucin 2 and tight junction proteins,increasing(P<0.05)Se availability,and maintaining mitochondrial structure and function,thereby improving antioxidant capacity and immunity.Furthermore,metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis,secretion and action of parathyroid hormone,proximal tubule bicarbonate reclamation and tricarboxylic acid cycle.Moreover,SeNPs increased(P<0.05)the abundance of Holdemanella and the levels of acetate and propionate.Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism.Overall,replacing dietary Na_(2)SeO_(3)with biogenic SeNPs could be a potential nutritional intervention strategy to prevent earlyweaning syndrome in piglets.

Advances in selenium supplementation:From selenium-enriched yeast to potential selenium-enriched insects,and selenium nanoparticles

Selenium(Se)is an essential micronutrient that plays an important role in animal and human development and physiological homoeostasis.This review surveys the role of Se in the environment,plants and animal bodies,and discusses data on Se biofortification with different sources of supplementation,from inorganic to organic forms,with special focus on Se-enriched yeast(Se-yeast).Although Se-yeast remains one of the main sources of organic Se,other emerging and innovative sources are reviewed,such as Se-enriched insects and Se-nanoparticles and their potential use in animal nutrition.Se-enriched insects are discussed as an option for supplying Se in organic form to livestock diets.Se-nanoparticles are also discussed,as they represent a more biocompatible and less toxic source of inorganic Se for animal organisms,compared to selenite and selenate.We also provide up to date information on the legal framework in the EU,USA,and Canada of Se that is contained in feed additives.From the scientific evidence available in the literature,it can be concluded that among the inorganic forms,sodium selenite is still one of the main options,whereas Se-yeast remains the primary organic form.However,other potential sources such as Se-enriched insects and Se-nanoparticles are being investigated as they could potentially combine a high bioavailability and reduced Se emissions in the environment.

Targeted anti-tumor synergistic effects of Myc decoy oligodeoxynucleotides-loaded selenium nanostructure combined with chemoradiotherapy on LNCaP prostate cancer cells

In the present study,we investigated the synergistic effects of targeted methotrexate-selenium nanostructure containing Myc decoy oligodeoxynucleotides along with X-irradiation exposure as a combination therapy on LNCaP prostate cancer cells.Myc decoy ODNs were designed based on the promoter of Bcl-2 gene and analyzed by molecular docking and molecular dynamics assays.ODNs were loaded on the synthesized Se@BSA@Chi-MTX nanostructure.The physicochemical characteristics of nanostructures were determined by FTIR,DLS,UV-vis,TEM,EDX,in vitro release,and hemolysis tests.Subsequently,the cytotoxicity properties of them with and without X-irradiation were investigated by uptake,MTT,cell cycle,apoptosis,and scratch assays on the LNCaP cell line.The results of DLS and TEM showed negative charge(−9 mV)and nanometer size(40 nm)for Se@BSA@Chi-DEC-MTX NPs,respectively.The results of FTIR,UV-vis,and EDX showed the proper interaction of different parts and the correct synthesis of nanoparticles.The results of hemolysis showed the hemocompatibility of this nanoparticle in concentrations less than 6 mg/mL.The ODNs release from the nanostructures showed a pH-dependent manner,and the release rate was 15%higher in acidic pH.The targeted Se@BSA@Chi-labeled ODN-MTX NPs were efficiently taken up by LNCaP cells by targeting the prostate-specific membrane antigen(PSMA).The significant synergistic effects of nanostructure(containing MTX drug)treatment along with X-irradiation showed cell growth inhibition,apoptosis induction(~57%),cell cycle arrest(G2/M phase),and migration inhibition(up to 90%)compared to the control.The results suggested that the Se@BSA@Chi-DEC-MTX NPs can potentially suppress the cell growth of LNCaP cells.This nanostructure system can be a promising approach for targeted drug delivery and chemoradiotherapy in prostate cancer treatment.

Construction of highly stable selenium nanoparticles embedded in hollow nanofibers of polysaccharide and their antitumor activities

Nanotechnologies have been exploited to develop safe and effective medicines and pharmaceuticals.In the present study,a novel functional nanomedicine constructed from a bioactive polysaccharide and selenium nanoparficles （SeNPs） was developed.A highly-branched [3-（1→3）-D-glucan （AF1） with high anti-tumor activity was used to self-assemble hollow nanofibers with an apparent average diameter of 92 nm;Se nanopartides were synthesized via the reduction of sodium selenite.The results of light scattering,transmission electron microscopy,and X-ray diffraction demonstrated that the spherical SeNPs with a mean diameter of 46 nm were entrapped in the cavities of the AF1 hollow nanofibers through the formation of Se-O bonds between SeNPs and AF1,leading to the good dispersion and high stability in water for over 16 months.In vitro and in vivo assays indicated that the AF1-Se nanocomposite had higher anti-tumor activities against breast cancer.Furthermore,AF1-Se displayed a broad-spectrum inhibition against human cancers with low half maximal inhibitory concentration （IC50） values and low toxicity to normal cells.Particularly,the inhibition ratio of AF1-Se against MCF-7 cancer cells reached 75% at a concentration of 200 μg.mL-1 with 29 μM Se content,much higher than that by treatment with AF1 alone,suggesting a strong synergic effect and nano impact.Overall,we developed a method for increasing the stability,anti-tumor activity,and safety of SeNPs by wrapping with bioactive polysaccharides.

Green-synthetized selenium nanoparticles using berberine as a promising anticancer agent

Objective: The chemo-preventative and therapeutic properties of selenium nanoparticles(Se NPs) have been documented over recent decades and suggest the potential uses of Se NPs in medicine. Biogenic Se NPs 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 Se NPs by using berberine(Ber) as an antitumor agent and elucidated the mechanism by which these molecules combat Ehrlich solid tumors(ESTs).Methods: Se NPs containing Ber(Se NPs-Ber) were synthesized using Ber and Na2 Se O3 and characterized with Fourier transform infrared spectroscopy. Sixty male Swiss albino mice were then acclimatized for one week, injected with Ehrlich ascites tumor cells, and divided into four groups: EST, EST + cisplatin(5 mg/kg), EST + Ber(20 mg/kg), and EST + Se NPs-Ber(0.5 mg/kg). At the end of a 16-day observation period, 12 mice from each group were euthanized to analyze differences in the body weight, tumor size,gene expression, and oxidative stress markers in the four groups. Three mice from each group were kept alive to compare the survival rates.Results: Treatment with Se NPs-Ber significantly improved the survival rate and decreased the body weight and tumor size, compared to the EST group. Se NPs-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, Se NPs-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. Se NPs-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 Se NPs by using Ber as a promising anticancer agent, these molecules could be used alone or as supplementary medication during chemotherapy.

Selenium nanoparticles derived from Proteus mirabilis YC801 alleviate oxidative stress and inflammatory response to promote nerve repair in rats with spinal cord injury

Microbial biotransformation and detoxification of biotoxic selenite into selenium nanoparticles(SeNPs)has emerged as an efficient technique for the utilization of selenium.SeNPs are characterized by high bioavailability and have several therapeutic effects owing to their antioxidant,anti-inflammatory and neuroprotective activities.However,their influence onmicroenvironment disturbances and neuroprotection after spinal cord injury(SCI)is yet to be elucidated.This study aimed to assess the influence of SeNPs on SCI and explore the underlying protective mechanisms.Overall,the proliferation and differentiation of neural stem cells were facilitated by SeNPs derived from Proteus mirabilis YC801 via the Wnt/b-catenin signaling pathway.The SeNPs increased the number of neurons to a greater extent than astrocytes after differentiation and improved nerve regeneration.A therapeutic dose of SeNPs remarkably protected the integrity of the spinal cord to improve the motor function of the hind limbs after SCI and decreased the expression of several inflammatory factors such as tumor necrosis factor-a and interleukin-6 in vivo and enhanced the production of M2-type macrophages by regulating their polarization,indicating the suppressed inflammatory response.Besides,SeNPs reversed the SCI-mediated production of reactive oxygen species.In conclusion,SeNPs treatment holds the potential to improve the disturbed microenvironment and promote nerve regeneration,representing a promising therapeutic approach for SCI.

Orthopedic revolution:The emerging role of nanotechnology

This review summarizes the latest progress in orthopedic nanotechnology,ex-plores innovative applications of nanofibers in tendon repair,and evaluates the potential of selenium and cerium oxide nanoparticles in osteoarthritis and osteo-blast differentiation.This review also describes the emerging applications of inje-ctable hydrogels in cartilage engineering,emphasizing the critical role of inter-disciplinary research and highlighting the challenges and future prospects of in-tegrating nanotechnology into orthopedic clinical practice.This comprehensive approach provides a holistic perspective on the transformative impact of nanote-chnology in orthopedics,offering valuable insights for future research and clinical applications.

Turning carbon dots into selenium bearing nanoplatforms with in vitro GPx-like activity and pro-oxidant activity

Selenium(Se)has been defined as the“Janus element”,with one face showing antioxidant activity and the other pro-oxidant activity.The biological effect of Se depends on both dose and speciation.Se nanoparticles are attracting major interest,although their large-scale preparation for biomedical applications is not trivial.We hypothesize that acid anhydride-coated carbon dots(AACD)are an attractive platform for preparing nanoparticles containing chemically defined Se.The reaction of AA-CD with 3-selenocyanatopropan-1-amine yields carbon dots bearing selenocyanate and carboxylate groups(CD-SeCN)that allow for tuning the hydrosolubility.CD-SeCN has a Se content of 0.36μmol per mg of nanoparticles,they show the typical photoluminescence of carbon dots.The selenocyanate groups(SeCN)exhibited glutathione peroxidase-like activity and cytotoxicity.Data show that antioxidant behavior differs between normal and tumor cells,the evaluation on HEK293 and A549 cells reveals that the toxicity of CD-SeCN depends on dose,time,intracellular glutathione(GSH)content.The toxicity of CD-SeCN decreases with the time of incubation and the cell death mechanism switches from necrosis to apoptosis,indicating that CD-SeCN is neutralized.Additionally,high levels of intracellular GSH exert a protective effect.These results support a pharmacological potential in cancers with low levels of intracellular GSH.The use of AA-CD as nanoplatforms is a general strategy that paves the way for the engineering of advanced nanosystems.

Preparation and Characterization of Nano-Se/Silk Fibroin Colloids

A solution-phase approach to the synthesis of nano-Se/silk fibroin colloids（NSeSFC） by reducing selenious acid solution with silk fibroin（SF） was proposed, and the composites were in situ prepared by macrowave method. The nanocomposites were characterized with ultraviolet-visible（UV-Vis） absorption spectrometry, resonance Rayleigh scattering（RRS） spectrometry and transmission electron microscopy（TEM）. The nano-Se（0） solution exhibited the strongest resonance Rayleigh scattering at 579 rim. Through the RRS discussion, we found the best preparation and conservation condition of NSeSFC. The TEM image shows the sizes of the Se（0） particles were about 50 nm and dispersed equably. The resulted NSeSFC exhibited good stability, and it can be kept for a long period.