This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their hig...This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their high compatibility with polymers and strong fluorescence.However,as the common magnetic material Fe_(3)O_(4)can quench their fluorescence,it is hard to synthesize Eu complexdoped magnetic fluorescent materials.To maintain fluorescence in the presence of magnetic parts,in this work,we synthesized Eu-doped magnetic microspheres with multi-layered structure.Firstly,poly-(glycidyl methacrylate)(PGMA)microspheres were prepared as templates and subsequently coated with layers of Fe_(3)O_(4)and SiO_(2).Then,the synthesized Eu(TTA)_(3)(TPPO)_(2)were added into PGMA@Fe_(3)O_(4)@SiO_(2)microspheres in either basic or acidic conditions,and covered them with an extra sol-gel layer of silica at the same time.The microspheres exhibit a core-shell structure with sub-micron dimensions(580 nm)and possess favorable superparamagnetic properties(M_(s)=22.02 A·m^(2)/kg,Mr=1.37 A·m^(2)/kg,H_(c)=0.242 A/m).But the fluorescence of Eu^(3+)are significantly quenched by Fe_(3)O_(4),O-H oscillators,and N-H oscillators.Finally,to exclude the quenching mentioned above,the first pure SiO_(2)shielding layer and the second Eu(TTA)_(3)(TPPO)_(2)-dispersed SiO_(2)layer were coated onto PGMA@Fe_(3)O_(4)microspheres to prevent the energy transfer due to the quenching centers and hold the fluorescence of Eu^(3+).These findings underscore the considerable potential of these microspheres exhibiting rapid magnetic separation and stable fluorescence for bioimaging and biosensing applications.展开更多
The highly conserved human leukocyte antigen-A2(HLA-A2)-restricted epitope NS3-1073 represents a promising candidate for a therapeutic vaccine against hepatitis C virus(HCV).In this study,we engineered a set of fusion...The highly conserved human leukocyte antigen-A2(HLA-A2)-restricted epitope NS3-1073 represents a promising candidate for a therapeutic vaccine against hepatitis C virus(HCV).In this study,we engineered a set of fusion proteins based on the artificial self-assembling peptide(SAP),which were expressed in Escherichia coli and spontaneously self-assembled into nanosized particles displaying HCV epitopes,including NS3-1073.To enhance immunogenicity,we incorporated the T helper epitope PADRE into the construct.Alpha-helical linkers were introduced between SAP and the epitopes to facilitate proper protein folding.Notably,a helical linker with a high supercoiling propensity enabled soluble expression of the fusion protein containing both the NS3-1073 and PADRE epitopes,allowing purification of the in vivo-formed nanoparticles by metal affinity chromatography.Human dendritic cells derived from peripheral blood monocytes showed robust activation in response to the fusion proteins and preferentially stimulated T lymphocytes toward a Th1-biased immune response.In mice,immunization with nanoparticles carrying NS3-1073 induced splenocyte proliferation in response to in vitro stimulation with a mixture of NS3 peptides.These results demonstrate that recombinant nanoparticle-based carriers presenting the NS3-1073 epitope can be produced in bacterial systems and hold strong potential as a foundation for a therapeutic HCV vaccine.展开更多
An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(C...An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(Ce6)and triethoxy(1H,1H,2H,2H‑nonafluorohexyl)silane(TFS)was coated on the outer layer of UC,and then a layer of HKUST‑1 shell was coated.The obtained nanocomposite UC@Ce6/TFS@mSiO_(2)@HKUST‑1(noted as UCTSH)was used for the synergistic treatment of chemodynamic therapy(CDT)and photodynamic therapy(PDT).Interestingly,the nanostructures can specifically re lease Cu^(2+)in the acidic tumor microenvironment.Cu^(2+)reacts with excess hydrogen peroxide(H_(2)O_(2))in the tumor microenvironment to form cytotoxic hydroxyl radical.Secondly,Ce6,with the action of oxygen‑carrying TFS,selectively produces a large amount of singlet oxygen by 808 nm laser irradiation.UCTSH can enhance the anti‑tumor effects of PDT and CDT by increasing the production level of reactive oxygen species,without causing damage to normal cells.展开更多
The widespread use and casual disposal of nanoproducts increase human exposure to nanoparticles(NPs),posing potential health risks.When coming into contact with biofluid,NPs passively move in the bloodstream and reach...The widespread use and casual disposal of nanoproducts increase human exposure to nanoparticles(NPs),posing potential health risks.When coming into contact with biofluid,NPs passively move in the bloodstream and reach target organs and cells.The nano-bio interactions,distribution,and fate of NPs are highly dependent on their physicochemical properties after direct exposure into the systemic circulation.In this study,silver nanoparticles(AgNPs)and gold nanoparticles(AuNPs)with the same size,shape,surface chemistry,and particle number but different densities were co-exposed to mice to explore their blood circulation and liver accumulation.The co-exposure avoids the individual differences in a single-material exposure model.Post-exposure,Au remained longer in the bloodstream than Ag,while 92.2%of the injected dose(%ID)of Ag accumulated in the liver compared to 78.0%for Au.Over a span of 3 to 72 h,Ag content in bloodstream increased while Au was undetectable.In the liver,the%ID of Ag sharply decreased to 9.4%,while the%ID of Au remained nearly unchanged.We proved the gradual dissociation of AgNPs into Ag ions using a fluorescent probe.Therefore,density-dependent dynamics of NPs in the blood caused greater liver accumulation of low-density Ag.However,the gradual degradation of AgNPs contributes to a high degree of distribution of Ag in the body while the AuNPs remain sequestered in the liver.This study implies that the dynamic transformation of NPs complicates their density-dependent retention,which are plausible to determine the accumulation and biological effects to the organisms.展开更多
Objectives:Prostate cancer cells often develop mechanisms to evade conventional therapies.Nanomedicine offers the potential for targeted drug delivery,improved tumor accumulation,and reduced systemic toxicity.This stu...Objectives:Prostate cancer cells often develop mechanisms to evade conventional therapies.Nanomedicine offers the potential for targeted drug delivery,improved tumor accumulation,and reduced systemic toxicity.This study biosynthesizes silver nanoparticles(NPP/AgONPs)functionalized with propolis,evaluates their antibacterial efficacy against uropathogenic strains of Escherichia coli(E.coli),and assesses their cytotoxic effect on cancer cell proliferation using the PC-3,human prostate epithelial cell line.Methods:The synthesized NPP/AgONPs physiochemical parameters were characterized,followed by in vitro assays to evaluate their antibacterial activity against multiple uropathogenic E.coli strains;determining the cytotoxicity against HPrEC and PC-3 cells by measuring cytotoxicity(CC_(50))and inhibition concentration(IC_(50)),respectively;analyzing cell cycle distribution and apoptosis via flow cytometry;and quantifying the reactive oxygen species(ROS),Caspase 3,and Caspase 8 expression in treated cells to elucidate mechanisms of cell death and growth inhibition.Results:NPP/AgONPs exhibited an average particle size of 22 nm,with four major X-ray diffraction(XRD)peaks corresponding to Joint Committee on Powder Diffraction Standards(JCPDS)No.01-1164,confirming their crystallinity.Moreover,the UV-vis absorbance at 390 nm yielded an energy gap of 2.45 eV.Antibacterial testing showed potent activity against the tested E.coli strains.In HPrEC and PC-3 cells,the CC_(50) was 262.04µg/mL,while the IC_(50) was 25.34μg/mL,respectively.Flow cytometry revealed increased apoptosis in the NPP/AgONPs-treated group across all stages,including early,late,and dead cells,compared with the controls.ROS,Caspase 3,and Caspase 8 levels were inflected in NPP/AgONPs-treated cells,showing apoptotic and growth-inhibitory effects.Conclusion:The propolis coating improves the nanoparticles’biocompatibility while enabling potent ROS-mediated apoptosis and cell-cycle disruption in PC-3 cells.These findings support the potential of NPP/AgONPs as a synergistic therapeutic platform,though optimization of dosing,detailed mechanism elucidation,and assessment of long-term safety are warranted.展开更多
We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and...We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.展开更多
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
To investigate the dispersion and deposition behavior of the nanoparticles(NPs)in the molten steel under the combined effects of turbulent flow and Brownian motion,a 3D model utilizing volume of fluid-discrete phase m...To investigate the dispersion and deposition behavior of the nanoparticles(NPs)in the molten steel under the combined effects of turbulent flow and Brownian motion,a 3D model utilizing volume of fluid-discrete phase model was developed based on a small-size ingot casting process.A modified Brownian motion model was implemented into the simulation using user-defined function to more accurately predict the motion behavior and distribution of the NPs in the molten steel.The results show that the NPs tend to deposit at the bottom or disperse toward the wall under the turbulent flow.The introduction of Brownian motion increases the horizontal dispersion rate(DH)to 21.3%and reduces the bottom deposition rate by 12.8%.A reduction in the particle size and density promotes higher particle mobility,characterized by increased velocity and DH,along with diminished deposition.As the particle size decreases to 1×10^(-7)m,Brownian motion becomes a significant factor influencing the particle dynamics.Additionally,increasing the initial velocity of the molten steel results in a lower DH of the particles.However,once the velocity exceeds 0.15 m s^(-1),its influence on the particle velocity becomes negligible.展开更多
Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity an...Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.展开更多
The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivi...The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.展开更多
Cancer has been recognized as one of the leading causes of mortality for decades.Magnetic resonance imaging(MRI)is a powerful imaging technology that has been widely applied in tumor diagnosis.Herein,we report the syn...Cancer has been recognized as one of the leading causes of mortality for decades.Magnetic resonance imaging(MRI)is a powerful imaging technology that has been widely applied in tumor diagnosis.Herein,we report the synthesis of magnetic iron oxide nanoparticles(MIONs)functionalized with multidentate thioether polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(methacrylic acid)(PTMPPMAA).Cytotoxicity assessment via the CCK-8 assay confirmed the low toxicity of the nanoparticles.MRI results showed excellent negative contrast enhancement.Bio-distribution study indicated gradual excretion of the nanoparticles.These MIONs@PTMP-PMAA exhibit strong negative contrast enhancement and present great potential as T_(2)-weighted contrast agents for MRI.展开更多
Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via lo...Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.展开更多
Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techni...Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techniques,including X-ray diffraction,transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).XRD results reveal high crystallinity,with characteristic peaks corresponding to Nd_(2)Se_(3),while TEM analysis shows rod-shaped nanoparticles with an average size of~55 nm.The presence of neodymium and selenium in the+3 oxidation state was confirmed by XPS.Thermogravimetric analysis indicates that theβ-cyclodextrin-citrate coating accounts for approximately30%of the nanoparticle mass and remains stable up to 800℃.The optical properties of the nanoparticles were studied using UV-Vis-NIR spectroscopy,revealing broad absorption in the UV and NIR regions.Magnetic characterization shows soft ferromagnetic behavior,with a saturation magnetization value of0.20 emu/g.The nanoparticles were used for controlled release of 5-fluorouracil,exhibiting a pHsensitive release profile.Studies on MCF-7 cells demonstrate that 5-fluorouracil-loade d nanoparticles enhance cytotoxicity,reactive oxygen species generation,and apoptosis compared to bare nanoparticles.The IC_(50) value of(13.78±1.24)μg/mL indicates a significantly high cytotoxic activity of the drug-loaded nanoparticles against breast cancer cell lines.These findings suggest that the nanoparticles are a promising drug delivery system for enhanced cancer treatment,combining the controlled drug release with targeted cellular effects.展开更多
Amorphous metal-based catalysts are highly promising for water splitting due to their abundance of unsaturated active sites.Herein,we report a one-step,surfactant-free synthesis of amorphous nickel nanoparticles(NPs)e...Amorphous metal-based catalysts are highly promising for water splitting due to their abundance of unsaturated active sites.Herein,we report a one-step,surfactant-free synthesis of amorphous nickel nanoparticles(NPs)encapsulated in nitrogen-doped carbon shells(A-Ni@NC)via pulsed laser ablation in liquid(PLAL).The synergistic integration of the amorphous Ni core and a defect-rich N-doped carbon shell markedly enhanced the catalytic activities for both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with low overpotentials of 182 mV for HER and 288 mV for OER at 10 mA cm^(-2)in 1.0 m KOH.Furthermore,the bifunctional catalyst achieved a current density of 10 mA cm^(-2)at 1.63 V and retained 98.9%of its initial performance after 100 h of operation.The nitrogen-rich carbon shell not only offered abundant active sites and structural protection but also promoted charge transport.Density functional theory(DFT)calculations revealed that N-doping optimized intermediate adsorption energies,while the amorphous Ni core facilitated efficient electron transfer.This green and scalable synthesis strategy provides a promising platform for developing a wide range of transition metal@N-doped carbon hybrid catalysts for sustainable energy conversion applications.展开更多
Nucleic acid-based therapies have emerged as promising strategies for the regulation of gene expression and the production of therapeutic antigens or proteins for a series of diseases, including cancers, rare diseases...Nucleic acid-based therapies have emerged as promising strategies for the regulation of gene expression and the production of therapeutic antigens or proteins for a series of diseases, including cancers, rare diseases, and infectious diseases. However, their clinical application faces challenges. These include high molecular weight, limited cellular uptake,and susceptibility to enzymatic degradation by nucleases in vivo. Both viral and non-viral delivery vectors have been developed as a means of addressing these limitations, including lipid nanoparticles(LNPs), exosomes, polymers, and inorganic nanoparticles. Among these,LNPs have garnered significant attention due to their superior biocompatibility, high delivery efficiency and customizable design potential, as demonstrated by the clinical success of the FDA-approved si RNA drug Onpattro®. The critical role of nucleic acid drug carriers is discussed in this review. It also outlines the major types of carriers under development and examines the advancements and applications in LNP-based systems for nucleic acid delivery. By conducting a review of recent advancements in LNP design, delivery mechanisms, and clinical applications, this article aims to clarify the ways in which LNPs overcome delivery barriers, compare LNPs with other carriers, and identify key trends that can inform the development of next-generation LNP platforms for nucleic acid therapeutics.展开更多
Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(...Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.展开更多
Polysaccharide coated PLA nanoparticles bearing aldehyde groups were prepared by dialysis of DMSO solution of cholesterol hydrophobic-modified dextran polyaldehyde and PLA against water.The average diameter of the nan...Polysaccharide coated PLA nanoparticles bearing aldehyde groups were prepared by dialysis of DMSO solution of cholesterol hydrophobic-modified dextran polyaldehyde and PLA against water.The average diameter of the nanoparticles was about 160 nm,and the size distribution was nearly homogenous.The nanoparticles were functionalized simultaneously with CD71 and EGFR antibody through the Schiff s base reaction,and then radiolabeled with ^(99m)Tc.After perfused the radiolabeled nanoparticles into tumor-bearing ra...展开更多
This paper describes a new formulation of magnetic nanoparticles coated by a novel polymer matrix-O-Carboxylmethylated Chitosan (O-CMC) as drug/gene carrier. The O-CMC magnetic nanoparticles were derivatized with a pe...This paper describes a new formulation of magnetic nanoparticles coated by a novel polymer matrix-O-Carboxylmethylated Chitosan (O-CMC) as drug/gene carrier. The O-CMC magnetic nanoparticles were derivatized with a peptide sequence from the HIV-tat protein and transferrin to improve the translocational property and cellar uptake of the nanoparticles. To evaluate the O-MNPs-Tat-Tf as drug carriers, Methotrexate (MTX) was incorporated as a model drug and MTX-loaded O-MNPs-Tat-Tf with an average diameter of 75nm were prepared and characterized by TEM, AFM and VSM. The cytotoxicity of MTX-loaded O-MNPs-Tat-Tf was investigated with C6 cells. The results showed that the MTX-loaded O-MNPs-Tat-Tf retained significant antitumor toxicity; additionally, sustained release of MTX from O-CMC nanoparticles was observed in vitro, suggesting that the O-MNPs-Tat-Tf could be a novel magnetic targeting carrier. We also studied the ability of O-MNPs-Tat-Tf crossing BBB in rats by single photon emission computed tomography (SPECT).展开更多
Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are...Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution.In this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing agent.Experimental analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs.The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation.After the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite hydrogel.The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs.The prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.展开更多
基金Project supported by the"Leading Goose"R&D Program(2022C01142)of Zhejiang Provincethe National Key R&D Program of China(2022YFB3503700)。
文摘This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications.Conventionally,dopants have utilized europium(Ⅲ)(Eu(Ⅲ))organic complexes due to their high compatibility with polymers and strong fluorescence.However,as the common magnetic material Fe_(3)O_(4)can quench their fluorescence,it is hard to synthesize Eu complexdoped magnetic fluorescent materials.To maintain fluorescence in the presence of magnetic parts,in this work,we synthesized Eu-doped magnetic microspheres with multi-layered structure.Firstly,poly-(glycidyl methacrylate)(PGMA)microspheres were prepared as templates and subsequently coated with layers of Fe_(3)O_(4)and SiO_(2).Then,the synthesized Eu(TTA)_(3)(TPPO)_(2)were added into PGMA@Fe_(3)O_(4)@SiO_(2)microspheres in either basic or acidic conditions,and covered them with an extra sol-gel layer of silica at the same time.The microspheres exhibit a core-shell structure with sub-micron dimensions(580 nm)and possess favorable superparamagnetic properties(M_(s)=22.02 A·m^(2)/kg,Mr=1.37 A·m^(2)/kg,H_(c)=0.242 A/m).But the fluorescence of Eu^(3+)are significantly quenched by Fe_(3)O_(4),O-H oscillators,and N-H oscillators.Finally,to exclude the quenching mentioned above,the first pure SiO_(2)shielding layer and the second Eu(TTA)_(3)(TPPO)_(2)-dispersed SiO_(2)layer were coated onto PGMA@Fe_(3)O_(4)microspheres to prevent the energy transfer due to the quenching centers and hold the fluorescence of Eu^(3+).These findings underscore the considerable potential of these microspheres exhibiting rapid magnetic separation and stable fluorescence for bioimaging and biosensing applications.
基金supported by the Russian Science Foundation(Grant No.24-25-20087 to V.K.)。
文摘The highly conserved human leukocyte antigen-A2(HLA-A2)-restricted epitope NS3-1073 represents a promising candidate for a therapeutic vaccine against hepatitis C virus(HCV).In this study,we engineered a set of fusion proteins based on the artificial self-assembling peptide(SAP),which were expressed in Escherichia coli and spontaneously self-assembled into nanosized particles displaying HCV epitopes,including NS3-1073.To enhance immunogenicity,we incorporated the T helper epitope PADRE into the construct.Alpha-helical linkers were introduced between SAP and the epitopes to facilitate proper protein folding.Notably,a helical linker with a high supercoiling propensity enabled soluble expression of the fusion protein containing both the NS3-1073 and PADRE epitopes,allowing purification of the in vivo-formed nanoparticles by metal affinity chromatography.Human dendritic cells derived from peripheral blood monocytes showed robust activation in response to the fusion proteins and preferentially stimulated T lymphocytes toward a Th1-biased immune response.In mice,immunization with nanoparticles carrying NS3-1073 induced splenocyte proliferation in response to in vitro stimulation with a mixture of NS3 peptides.These results demonstrate that recombinant nanoparticle-based carriers presenting the NS3-1073 epitope can be produced in bacterial systems and hold strong potential as a foundation for a therapeutic HCV vaccine.
文摘An upconversion nanoparticle(NaErF_(4)∶Yb/Tm@NaLuF_(4)∶Yb@NaLuF_(4)∶Nd/Yb@NaLuF_(4),noted as UC)was designed,emitting strong red light by 808 nm laser.The mesoporous silica(mSiO_(2))shell co‑doped with chlorin e6(Ce6)and triethoxy(1H,1H,2H,2H‑nonafluorohexyl)silane(TFS)was coated on the outer layer of UC,and then a layer of HKUST‑1 shell was coated.The obtained nanocomposite UC@Ce6/TFS@mSiO_(2)@HKUST‑1(noted as UCTSH)was used for the synergistic treatment of chemodynamic therapy(CDT)and photodynamic therapy(PDT).Interestingly,the nanostructures can specifically re lease Cu^(2+)in the acidic tumor microenvironment.Cu^(2+)reacts with excess hydrogen peroxide(H_(2)O_(2))in the tumor microenvironment to form cytotoxic hydroxyl radical.Secondly,Ce6,with the action of oxygen‑carrying TFS,selectively produces a large amount of singlet oxygen by 808 nm laser irradiation.UCTSH can enhance the anti‑tumor effects of PDT and CDT by increasing the production level of reactive oxygen species,without causing damage to normal cells.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XPDB0750300)the National Natural Science Foundation of China (Nos. 22036002, 22325606,22206037, 22106176, and 21527901)the Scientific Instrument and Equipment Developing Project of the Chinese Academy of Sciences (No.YJKYYQ20210020).
文摘The widespread use and casual disposal of nanoproducts increase human exposure to nanoparticles(NPs),posing potential health risks.When coming into contact with biofluid,NPs passively move in the bloodstream and reach target organs and cells.The nano-bio interactions,distribution,and fate of NPs are highly dependent on their physicochemical properties after direct exposure into the systemic circulation.In this study,silver nanoparticles(AgNPs)and gold nanoparticles(AuNPs)with the same size,shape,surface chemistry,and particle number but different densities were co-exposed to mice to explore their blood circulation and liver accumulation.The co-exposure avoids the individual differences in a single-material exposure model.Post-exposure,Au remained longer in the bloodstream than Ag,while 92.2%of the injected dose(%ID)of Ag accumulated in the liver compared to 78.0%for Au.Over a span of 3 to 72 h,Ag content in bloodstream increased while Au was undetectable.In the liver,the%ID of Ag sharply decreased to 9.4%,while the%ID of Au remained nearly unchanged.We proved the gradual dissociation of AgNPs into Ag ions using a fluorescent probe.Therefore,density-dependent dynamics of NPs in the blood caused greater liver accumulation of low-density Ag.However,the gradual degradation of AgNPs contributes to a high degree of distribution of Ag in the body while the AuNPs remain sequestered in the liver.This study implies that the dynamic transformation of NPs complicates their density-dependent retention,which are plausible to determine the accumulation and biological effects to the organisms.
基金funded by Taibah University,Madinah,Kingdom of Saudi Arabia-with the grant number(447-16-1081).
文摘Objectives:Prostate cancer cells often develop mechanisms to evade conventional therapies.Nanomedicine offers the potential for targeted drug delivery,improved tumor accumulation,and reduced systemic toxicity.This study biosynthesizes silver nanoparticles(NPP/AgONPs)functionalized with propolis,evaluates their antibacterial efficacy against uropathogenic strains of Escherichia coli(E.coli),and assesses their cytotoxic effect on cancer cell proliferation using the PC-3,human prostate epithelial cell line.Methods:The synthesized NPP/AgONPs physiochemical parameters were characterized,followed by in vitro assays to evaluate their antibacterial activity against multiple uropathogenic E.coli strains;determining the cytotoxicity against HPrEC and PC-3 cells by measuring cytotoxicity(CC_(50))and inhibition concentration(IC_(50)),respectively;analyzing cell cycle distribution and apoptosis via flow cytometry;and quantifying the reactive oxygen species(ROS),Caspase 3,and Caspase 8 expression in treated cells to elucidate mechanisms of cell death and growth inhibition.Results:NPP/AgONPs exhibited an average particle size of 22 nm,with four major X-ray diffraction(XRD)peaks corresponding to Joint Committee on Powder Diffraction Standards(JCPDS)No.01-1164,confirming their crystallinity.Moreover,the UV-vis absorbance at 390 nm yielded an energy gap of 2.45 eV.Antibacterial testing showed potent activity against the tested E.coli strains.In HPrEC and PC-3 cells,the CC_(50) was 262.04µg/mL,while the IC_(50) was 25.34μg/mL,respectively.Flow cytometry revealed increased apoptosis in the NPP/AgONPs-treated group across all stages,including early,late,and dead cells,compared with the controls.ROS,Caspase 3,and Caspase 8 levels were inflected in NPP/AgONPs-treated cells,showing apoptotic and growth-inhibitory effects.Conclusion:The propolis coating improves the nanoparticles’biocompatibility while enabling potent ROS-mediated apoptosis and cell-cycle disruption in PC-3 cells.These findings support the potential of NPP/AgONPs as a synergistic therapeutic platform,though optimization of dosing,detailed mechanism elucidation,and assessment of long-term safety are warranted.
基金Funded by the National Natural Science Foundation of China(No.52371169)。
文摘We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金supported by the 111 Project(2.0)of China(No.BP0719037)the National Natural Science Foundation of China(No.51474065).
文摘To investigate the dispersion and deposition behavior of the nanoparticles(NPs)in the molten steel under the combined effects of turbulent flow and Brownian motion,a 3D model utilizing volume of fluid-discrete phase model was developed based on a small-size ingot casting process.A modified Brownian motion model was implemented into the simulation using user-defined function to more accurately predict the motion behavior and distribution of the NPs in the molten steel.The results show that the NPs tend to deposit at the bottom or disperse toward the wall under the turbulent flow.The introduction of Brownian motion increases the horizontal dispersion rate(DH)to 21.3%and reduces the bottom deposition rate by 12.8%.A reduction in the particle size and density promotes higher particle mobility,characterized by increased velocity and DH,along with diminished deposition.As the particle size decreases to 1×10^(-7)m,Brownian motion becomes a significant factor influencing the particle dynamics.Additionally,increasing the initial velocity of the molten steel results in a lower DH of the particles.However,once the velocity exceeds 0.15 m s^(-1),its influence on the particle velocity becomes negligible.
基金financially supported by the International Cooperation Program from the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)National Foreign Experts Program(No.G2022027015L)。
文摘Magnetic resonance imaging(MRI)is one of the most widely used diagnostic techniques.Iron oxide nanoparticles,as a promising kind of contrast agents,have attracted intense research interest due to their low toxicity and superparamagnetism.However,it is still a great challenge to prepare ideal iron oxide based contrast agents with high uniformity,excellent water solubility and biocompatibility.In this paper,a novel water-soluble polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(N-vinyl-2-pyrrolidone)(PTMP-PVP)was used as a capping reagent to prepare iron oxide nanoparticles MIONs@PTMP-PVP through one-step co-precipitation of iron precursors in aqueous solution at 100℃.The obtained nanoparticles MIONs@PTMP-PVP had a small size and narrow size distribution,and they were found to be biocompatible as determined through CCK-8 assay and histology analysis.In vivo MRI study demonstrated that the obtained MIONs@PTMP-PVP can be potentially used as an effective T_(2)-weighted MRI contrast agent.
文摘The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.
基金financially supported by the International Cooperation Program of the Ministry of Science and Technology of Hubei Province(No.2023EHA069)Shenzhen Science and Technology Program(No.JCYJ20230807143702005)+1 种基金National Foreign Experts Program(No.G2022027015L)the National Natural Science Foundation of China(No.82302265).
文摘Cancer has been recognized as one of the leading causes of mortality for decades.Magnetic resonance imaging(MRI)is a powerful imaging technology that has been widely applied in tumor diagnosis.Herein,we report the synthesis of magnetic iron oxide nanoparticles(MIONs)functionalized with multidentate thioether polymer ligand pentaerythritol tetrakis 3-mercaptopropionate-poly(methacrylic acid)(PTMPPMAA).Cytotoxicity assessment via the CCK-8 assay confirmed the low toxicity of the nanoparticles.MRI results showed excellent negative contrast enhancement.Bio-distribution study indicated gradual excretion of the nanoparticles.These MIONs@PTMP-PMAA exhibit strong negative contrast enhancement and present great potential as T_(2)-weighted contrast agents for MRI.
基金the National Nature Science Foundation of China for Excellent Young Scientists Fund(32222058)Fundamental Research Foundation of CAF(CAFYBB2022QB001).
文摘Developing biomass platform compounds into high value-added chemicals is a key step in renewable resource utilization.Herein,we report porous carbon-supported Ni-ZnO nanoparticles catalyst(Ni-ZnO/AC)synthesized via low-temperature coprecipitation,exhibiting excellent performance for the selective hydrogenation of 5-hydroxymethylfurfural(HMF).A linear correlation is first observed between solvent polarity(E_(T)(30))and product selectivity within both polar aprotic and protic solvent classes,suggesting that solvent properties play a vital role in directing reaction pathways.Among these,1,4-dioxane(aprotic)favors the formation of 2,5-bis(hydroxymethyl)furan(BHMF)with 97.5%selectivity,while isopropanol(iPrOH,protic)promotes 2,5-dimethylfuran production with up to 99.5%selectivity.Mechanistic investigations further reveal that beyond polarity,proton-donating ability is critical in facilitating hydrodeoxygenation.iPrOH enables a hydrogen shuttle mechanism where protons assist in hydroxyl group removal,lowering the activation barrier.In contrast,1,4-dioxane,lacking hydrogen bond donors,stabilizes BHMF and hinders further conversion.Density functional theory calculations confirm a lower activation energy in iPrOH(0.60 eV)compared to 1,4-dioxane(1.07 eV).This work offers mechanistic insights and a practical strategy for solvent-mediated control of product selectivity in biomass hydrogenation,highlighting the decisive role of solvent-catalyst-substrate interactions.
文摘Neodymium selenide nanoparticles were synthesized and surface-modified usingβ-cyclodextrin-citrate to control agglomeration and achieve the desired particle size.The nanoparticles were characterized by various techniques,including X-ray diffraction,transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).XRD results reveal high crystallinity,with characteristic peaks corresponding to Nd_(2)Se_(3),while TEM analysis shows rod-shaped nanoparticles with an average size of~55 nm.The presence of neodymium and selenium in the+3 oxidation state was confirmed by XPS.Thermogravimetric analysis indicates that theβ-cyclodextrin-citrate coating accounts for approximately30%of the nanoparticle mass and remains stable up to 800℃.The optical properties of the nanoparticles were studied using UV-Vis-NIR spectroscopy,revealing broad absorption in the UV and NIR regions.Magnetic characterization shows soft ferromagnetic behavior,with a saturation magnetization value of0.20 emu/g.The nanoparticles were used for controlled release of 5-fluorouracil,exhibiting a pHsensitive release profile.Studies on MCF-7 cells demonstrate that 5-fluorouracil-loade d nanoparticles enhance cytotoxicity,reactive oxygen species generation,and apoptosis compared to bare nanoparticles.The IC_(50) value of(13.78±1.24)μg/mL indicates a significantly high cytotoxic activity of the drug-loaded nanoparticles against breast cancer cell lines.These findings suggest that the nanoparticles are a promising drug delivery system for enhanced cancer treatment,combining the controlled drug release with targeted cellular effects.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(NRF-2023R1A2C1005419).
文摘Amorphous metal-based catalysts are highly promising for water splitting due to their abundance of unsaturated active sites.Herein,we report a one-step,surfactant-free synthesis of amorphous nickel nanoparticles(NPs)encapsulated in nitrogen-doped carbon shells(A-Ni@NC)via pulsed laser ablation in liquid(PLAL).The synergistic integration of the amorphous Ni core and a defect-rich N-doped carbon shell markedly enhanced the catalytic activities for both the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),with low overpotentials of 182 mV for HER and 288 mV for OER at 10 mA cm^(-2)in 1.0 m KOH.Furthermore,the bifunctional catalyst achieved a current density of 10 mA cm^(-2)at 1.63 V and retained 98.9%of its initial performance after 100 h of operation.The nitrogen-rich carbon shell not only offered abundant active sites and structural protection but also promoted charge transport.Density functional theory(DFT)calculations revealed that N-doping optimized intermediate adsorption energies,while the amorphous Ni core facilitated efficient electron transfer.This green and scalable synthesis strategy provides a promising platform for developing a wide range of transition metal@N-doped carbon hybrid catalysts for sustainable energy conversion applications.
基金supported by the Regional University-Industry Technology Transfer Center for Biopharmaceuticals (Nanjing,Jiangsu) Early-Stage Translational Grant (JB2025211)。
文摘Nucleic acid-based therapies have emerged as promising strategies for the regulation of gene expression and the production of therapeutic antigens or proteins for a series of diseases, including cancers, rare diseases, and infectious diseases. However, their clinical application faces challenges. These include high molecular weight, limited cellular uptake,and susceptibility to enzymatic degradation by nucleases in vivo. Both viral and non-viral delivery vectors have been developed as a means of addressing these limitations, including lipid nanoparticles(LNPs), exosomes, polymers, and inorganic nanoparticles. Among these,LNPs have garnered significant attention due to their superior biocompatibility, high delivery efficiency and customizable design potential, as demonstrated by the clinical success of the FDA-approved si RNA drug Onpattro®. The critical role of nucleic acid drug carriers is discussed in this review. It also outlines the major types of carriers under development and examines the advancements and applications in LNP-based systems for nucleic acid delivery. By conducting a review of recent advancements in LNP design, delivery mechanisms, and clinical applications, this article aims to clarify the ways in which LNPs overcome delivery barriers, compare LNPs with other carriers, and identify key trends that can inform the development of next-generation LNP platforms for nucleic acid therapeutics.
基金supported by the National Key Research and Development Project(No.2020YFA0907500)the National Natural Science Foundation of China(No.22476206)+1 种基金the supports from the National Young Top-Notch Talents(No.W03070030)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y202011).
文摘Fe reducing bacteria(FRB),through extracellular electron transfer(EET)pathway,can reduce Fe(III)nanoparticles,thereby affecting the migration,transformation,and degradation of pollutants.However,the interaction of Fe(III)nanoparticles with the most commonly identified FRB,Geobacter sulfurreducens PCA,remains poorly understood.Herein,we demonstrated that the synergistic role of outer membrane proteins and periplasmic proteins in the EET process for-Fe_(2)O_(3),Fe3O4,and𝛽α-FeOOH nanoparticles by construction of multiple gene knockout strain.oxpG(involved in the type II secretion system)and omcST(outer membrane c-type cytochrome)medi-ated pathways accounted for approximately 67%of the total reduction of𝛼α-Fe_(2)O_(3) nanoparticles.The residual reduction of𝛼α-Fe_(2)O_(3) nanoparticles in∆oxpG-omcST strain was likely caused by redox-active substances in cell supernatant.Conversely,the reduction of dissolved Fe(III)was almost unaffected in∆oxpG-omcST strain at the same concentration.However,at high dissolved Fe(III)concentration,the reduction significantly decreased due to the formation of Fe(III)nanoparticles,suggesting that this EET process is specific to Fe(III)nanoparticles.Overall,our study provided a more comprehensive understanding for the EET pathways between G.sulfurreducens PCA and different Fe(III)species,enriching our knowledge on the role of microorganisms in iron biogeochemical cycles and remediation strategies of pollutants.
基金supported by the National Natural Scientific Foundation of China (No.50573056)Tianjin Science and Technology Committee (No.06YFGZSH00800).
文摘Polysaccharide coated PLA nanoparticles bearing aldehyde groups were prepared by dialysis of DMSO solution of cholesterol hydrophobic-modified dextran polyaldehyde and PLA against water.The average diameter of the nanoparticles was about 160 nm,and the size distribution was nearly homogenous.The nanoparticles were functionalized simultaneously with CD71 and EGFR antibody through the Schiff s base reaction,and then radiolabeled with ^(99m)Tc.After perfused the radiolabeled nanoparticles into tumor-bearing ra...
文摘This paper describes a new formulation of magnetic nanoparticles coated by a novel polymer matrix-O-Carboxylmethylated Chitosan (O-CMC) as drug/gene carrier. The O-CMC magnetic nanoparticles were derivatized with a peptide sequence from the HIV-tat protein and transferrin to improve the translocational property and cellar uptake of the nanoparticles. To evaluate the O-MNPs-Tat-Tf as drug carriers, Methotrexate (MTX) was incorporated as a model drug and MTX-loaded O-MNPs-Tat-Tf with an average diameter of 75nm were prepared and characterized by TEM, AFM and VSM. The cytotoxicity of MTX-loaded O-MNPs-Tat-Tf was investigated with C6 cells. The results showed that the MTX-loaded O-MNPs-Tat-Tf retained significant antitumor toxicity; additionally, sustained release of MTX from O-CMC nanoparticles was observed in vitro, suggesting that the O-MNPs-Tat-Tf could be a novel magnetic targeting carrier. We also studied the ability of O-MNPs-Tat-Tf crossing BBB in rats by single photon emission computed tomography (SPECT).
基金financially supported by the National Natural Science Foundation of China(No.52203209)the State Key Laboratory of Solid Waste Reuse for Building Materials,China(No.SWR-2022-009)the Fundamental Research Funds for the Central Universities,China(No.FRF-IDRY22-012)。
文摘Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial property.However,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water pollution.In this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing agent.Experimental analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag NPs.The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation.After the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite hydrogel.The inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag NPs.The prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.
