Recent progress of the preparation and applications of superparamagnetic iron oxide(SPIO) clusters as magnetic resonance imaging(MRI) probes is reviewed with regard to their applications in labeling and tracking c...Recent progress of the preparation and applications of superparamagnetic iron oxide(SPIO) clusters as magnetic resonance imaging(MRI) probes is reviewed with regard to their applications in labeling and tracking cells in vivo, in diagnosis of cardiovascular diseases and tumors, and in drug delivery systems. Magnetic nanoparticles(NPs), especially SPIO nanoparticles, have long been used as MRI contrast agents and as an advantageous nanoplatform for drug delivery,taking advantage of their unique magnetic properties and ability to function at the molecular and cellular levels. Due to advances in nanotechnology, various means to control SPIO NPs' size, composition, magnetization and relaxivity have been developed, as well as ways to usefully modify their surface. Recently, self-assembly of SPIO NP clusters in particulate carriers — such as polymeric micelles, vesicles, liposomes, and layer-by-layer(Lb L) capsules — have been widely studied for application as ultrasensitive MRI probes, owing to their remarkably high spin–spin(T2) relaxivity and convenience for further functionalization.展开更多
Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and...Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and interparticle spacing of the nanoparticles is very important. Here, we combine seed-mediated growth with nanosphere lithography to study the controllable growth of gold nanoparticles (Au NPs), in which the self-assembly monolayer of polystyrene (PS) on a silicon surface is used to guide the modification of allaunesilanes and the subsequent adsorption of gold seeds; seed-mediated growth is applied to controlling the morphology and size of Au NPs. The size of adsorption region (determining the number of adsorbed gold seeds) is controlled by etching PS microspheres with oxygen plasma or annealing PS microspheres at the glass transition temperature. The size and morphology of the Au NPs are controlled by changing growth conditions. In such a way, we have achieved the dual control of the obtained Au NPs. Preliminary results show that this strategy holds a great promise. This approach can also be extended to a wide range of materials and substrates.展开更多
Nanoparticles conjugated with antibody were designed as active drug delivery system to reduce the toxicity and side effects of drugs for acute myeloid leukemia(AML).Moreover,methotrexate(MTX)was chosen as modeldru...Nanoparticles conjugated with antibody were designed as active drug delivery system to reduce the toxicity and side effects of drugs for acute myeloid leukemia(AML).Moreover,methotrexate(MTX)was chosen as modeldrug and encapsulate within folic acid modified carboxymethylchitosan(FACMCS)nanoparticles through self-assembling.The chemicalstructure,morphology,release and targeting of nanoparticles were characterized by routine detection.It is demonstrated that the mean diameter is about 150 nm,the release rate increases with the decreasing of p H,the binding rate of CD33 antibody and FA-CMCS nanoparticles is about 5:2,and nanoparticles can effectively bind onto HL60 cells in vitro.The experimentalresults indicate that the FA-CMCS nanoparticles conjugated with antibody may be used as a potentialp Hsensitive drug delivery system with leukemic targeting properties.展开更多
With a two-phase method,well-dispersed 5.2 nm Ag nanoparticles with narrow size distribution (±0.5 nm) are synthesized.The assembled structures of colloidal Ag nanoparticles on highly oriented pyrolytic graphi...With a two-phase method,well-dispersed 5.2 nm Ag nanoparticles with narrow size distribution (±0.5 nm) are synthesized.The assembled structures of colloidal Ag nanoparticles on highly oriented pyrolytic graphite (HOPG),silicon chip and microscopic glass have been investigated by atomic force microscopy (AFM).With different spin-coating speeds and concentrations of colloidal silver nanoparticles,various assembly structures could form on those substrates.On HOPG,Ag nanoparticles were absorbed and aligned along single-atom-height step edges to form a linear one-layer structure.And on silicon chip and microscopic glass,one-layer closed packing fractal structure and two-layer closed packing ring were observed respectively.展开更多
Forming a monolayer of mixed nickel and gold nanoparticles through self-assembly via simple solution processing constitutes an important step toward inexpensive nanoparticle-based carbon nanofiber growth.In this work,...Forming a monolayer of mixed nickel and gold nanoparticles through self-assembly via simple solution processing constitutes an important step toward inexpensive nanoparticle-based carbon nanofiber growth.In this work,mixed gold and nickel nanoparticles were anchored on the silicon wafer using self-assembled monolayers(SAMs)as a template.SAMs of 3-mercaptopropyl trimethoxysilane(MPTS-SAMs)were formed on silicon wafer,with the exposed thiol functionality providing ligand exchange sites to form the mixed monolayer of nickel and gold nanoparticles via a two-step sequential soaking approach.The densities of the nickel and gold nanoparticles on the surface can be varied by adjusting the soaking sequence.展开更多
Combretastatin A4(CA4) possesses varying ability to cause vascular disruption in tumors,while the short half-life, low water solubility and deactivation of many CA4 analogs during storage limited its antitumor efficac...Combretastatin A4(CA4) possesses varying ability to cause vascular disruption in tumors,while the short half-life, low water solubility and deactivation of many CA4 analogs during storage limited its antitumor efficacy and drug stability. A novel macromolecular conjugate of CA4(CA4-PL) was synthesized by covalent bonding of CA4 onto poly(L-glutamic acid)-graft-polyethylene glycol(PLG-g-PEG) via Yamaguchi reaction. The obtained CA4-PL was characterized by ~1H NMR, GPC, and UV methods, and the properties of the nanoparticles composed of CA4-PL, including critical aggregation concentration, size and size distribution, and morphology, were investigated. CA4-PL can self-assemble to form micelle-like nanoparticles of 80~120 nm in diameter, which may have potential to improve the blood circulation period as well as the targetability of CA4, and find applications to treat various tumors when combined with traditional chemotherapy or radio therapy.展开更多
Zirconia nanoparticles were synthesized via hydrothermal method without any additives. This work focuses on the effect of preparation conditions1 such as the precursor preparation condition and crystallization time of...Zirconia nanoparticles were synthesized via hydrothermal method without any additives. This work focuses on the effect of preparation conditions1 such as the precursor preparation condition and crystallization time of nanocrystallite in autoclave on the properties of as-prepared products. The results indicated that the amount of tetragonal zirconia varied with the preparation conditions. It increased with the increase of the concentration of KOH solution in precursor producing process and reduced with the prolongation of crystallization time. At the same time, the particle size and morphology were also affected by the preparation conditions. In addition, the self-assembled spindle- like aggregates were observed in present works.展开更多
Self-assembled nanostructures of lipids and nanoparticles hold great promise for applications in such fields as nanomedicine. This paper uses the self-consistent field theory to investigate the self-assembly behavior ...Self-assembled nanostructures of lipids and nanoparticles hold great promise for applications in such fields as nanomedicine. This paper uses the self-consistent field theory to investigate the self-assembly behavior of lipid molecules and nanoparticles with different shapes in an aqueous solution. It is found that the lipid molecules can form monolayered and bilayered nanostructures around the nanopartieles with different shapes (e.g., triangular, square, hexagonal and octangular). With decreasing the size of nanoparticles or increasing the number of polygon edges, the shape of lipid layers will approach an approximately spherical shape. These findings may help to predict and design novel drug delivery nanocarriers.展开更多
The formation of Ag clusters on titanium oxide (TiO2) nanoparticles was achieved by self-assembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission ele...The formation of Ag clusters on titanium oxide (TiO2) nanoparticles was achieved by self-assembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet visible spectroscopy (UV-Vis), and conventional techniques (XRD, TEM and UV-Vis) were used to identify Ag particles on the TiO2 surfaces. The results show that Ag-TiO2 particles can be applied to improve catalytic activity of the epoxidation of styrene oxides. Styrene oxide is the main product of catalytic reaction with H2O2 as the oxidant by using Ag-TiO2 nanoparticles as catalysts. High catalytic activitity of styrene oxide can be obtainable at 80 ℃. The reaction temperature, reaction time, the molar ratio of H2O2/styrene and solvent affect greatly the catalytic epoxidation of styrene.展开更多
Comprehensive Summary Metal nanoparticles(NPs)decorated block copolymer(BCP)hybrid nanoparticles have attracted enormous attention for their actual value in catalysis,medical therapy,and bioengineering.The confined as...Comprehensive Summary Metal nanoparticles(NPs)decorated block copolymer(BCP)hybrid nanoparticles have attracted enormous attention for their actual value in catalysis,medical therapy,and bioengineering.The confined assembly of BCPs within evaporative emulsion droplet is verified as an effective method to provide polymeric scaffolds to load metal NPs.However,to date,it remains challenging to generate different types of metal NPs decorated BCP hybrid nanoparticles.Herein,we employed the emulsion confined self-assembly of poly(styrene-b-2-vinylpyridine)(PS-b-P2VP)and the followed seed-mediated growth of Au and palladium(Pd)NPs onto well-defined BCP particles to design a series of Au/Pd decorated BCP hybrid nanoparticles,which exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with the reductant of NaBH4.This work may inspire more researchers to investigate the selective decoration of different metal NPs onto the polymeric scaffolds,broadening the potential applications of the inorganic/organic hybrid nanoparticles.展开更多
A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and ...A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and amidation to introduce hydrazide groups.DOX was then grafted onto pullulan backbone through the pH-sensitive hydrazone bond to form a pullulan/DOX conjugate.This conjugate self-assembled to form nano-sized particles in aqueous solution as a result of the hydrophobic interaction of the DOX.Trans...展开更多
A novel method was presented to create composite micelles of amphiphilic copolymers and Ag nanoparticles(NPs) in a three-dimensional co-flow focusing microfluidic device(3D CFMD). Self-assembly of the copolymers was i...A novel method was presented to create composite micelles of amphiphilic copolymers and Ag nanoparticles(NPs) in a three-dimensional co-flow focusing microfluidic device(3D CFMD). Self-assembly of the copolymers was initiated by the fast mixing of water and a blend dispersion of hydrophobic Ag NPs and amphiphilic copolymers. At the same time, the hydrophobic Ag NPs enter the core of copolymer micelles, based on the hydrophobic interaction. The copolymer-Ag NPs composite micelles have a core-shell structure with copolymer shell and Ag NPs core. COMSOL Multiphysics is used to simulate the concentration distribution of copolymers and Ag NPs under different flow rates. Co-assembly microfluidic conditions are determined based on simulation results. Under suitable microfluidic conditions, both block copolymers and gradient copolymers can co-assemble with hydrophobic Ag NPs to form composite micelles, respectively. This microfluidic coassembly method will have a good prospect in the preparation of composite micelles of amphiphilic copolymers and metal nanoparticles.展开更多
This study compared a new type of polysaccharide-coated magnetic nanoparticles (in which the polysaccharide is derived from Angelica sinensis) with the dextran magnetic nanoparticles in terms of preparation, biocomp...This study compared a new type of polysaccharide-coated magnetic nanoparticles (in which the polysaccharide is derived from Angelica sinensis) with the dextran magnetic nanoparticles in terms of preparation, biocompatibility and tissue distribution in vivo and in vitro in order to examine the potential application of Angelica polysaccharide as a novel carrier in magnetic drug targeting (MDT). Magnetic nanoparticles were prepared by chemical co-precipitation. Their physical and chemical properties were determined by using the transmission electron microscope (TEM), laser particle size analyzer (DLS) and vibrating sample magnetometer (VSM), and their purity and structure by using X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). The atomic absorption spectrometric method was performed for quantification of the iron content in different tissues. Histological sections were stained by Prussian blue staining to observe the disposition of magnetic nanoparticles in the liver and kidney. The results showed that both kinds of magnetic nanoparticles possessed small particle size, good dispersion and good magnetic properties. XRD showed the main component of the two magnetic nanoparticles was Fe3O4 crystals, and FTIR proved Fe3O4 was successfully coated by each polysaccharide, respectively. In vivo, Fe3O4-dextran accumulated in the liver, spleen and lung and Fe3O4-Angelica polysaccharide only in the spleen and lung. It was concluded that Angelica polysaccharide may be applied as a novel carrier in the preparation of magnetic nanoparticles.展开更多
CdS nanoparticles were assembled on the smooth surface of a piece of silver by using 1,4-benzenedithiol as coupling molecules. The SEM and resonance Raman spectroscopic characterizations demonstrate that the nanosized...CdS nanoparticles were assembled on the smooth surface of a piece of silver by using 1,4-benzenedithiol as coupling molecules. The SEM and resonance Raman spectroscopic characterizations demonstrate that the nanosized structure of CdS was still preserved upon assembly, and a two-dimensional structure of CdS nanoparticles was formed on the substrate surface. The FT-Raman spectra indicate that 1,4-benzenedithiol was coupled between CdS nanoparticles and the silver surface with a tilted orientation. The Raman scattering of 1,4-benzenedithiol was substantially enhanced by the assembled CdS nanoparticles, probably due to the alteration of the polarizability of 1,4-benzenedithiol and the electromagnetic interaction between the dipoles of the CdS particle with its image in the metal substrate.展开更多
A novel strategy has been developed for construction of nanoparticle chains between nanoelectrodes with bifunctional molecules by taking advantage of linear aggregation of colloidal particles in organis solvents. As c...A novel strategy has been developed for construction of nanoparticle chains between nanoelectrodes with bifunctional molecules by taking advantage of linear aggregation of colloidal particles in organis solvents. As confirmed by scanning electron microscopy (SEM),an individual nanoparticle chain bridged the electrode pair. The present approach makes this technique to be cheap and may be applicable in microelectronic industry.展开更多
The intrinsic dynamics of two interacting electric polarized nanorods is theoretically investigated. The relative motion between them caused by electric dipole-dipole interaction is derived based on the generalized La...The intrinsic dynamics of two interacting electric polarized nanorods is theoretically investigated. The relative motion between them caused by electric dipole-dipole interaction is derived based on the generalized Lagrangian formulation. The results show that the relative translation and rotation are nonlinear and closely dependent on the initial configuration of the two nanorods. Furthermore, the general conditions of the initial configuration, which determine the two nanorods to repel or attract each other at the initial time, are obtained. The two-dimensional relative motion of the two nanorods shows that the antiparallel and head-to-tail ordering stable self-assembly are respectively formed in two planar initial configurations. For different three-dimensional initial configurations, the interesting dynamic relative attraction, repulsion, and oscillation with rotation are respectively realized. Finally, the theoretical schemes which realize the relaxing, direct head-to-tail ordering, and direct antiparallel ordering stable self-assembly are presented according to the different modes of the motion of the nanoparticles. Some of our results agree well with the results of experiments and simulations.展开更多
A dual-receptor targeting delivery system based on acid-cleavage hydrazone bond was developed in the study. The characters of CMCS-hyd-CUR-EGFR-mAb were identified. The in vitro release studies revealed that this drug...A dual-receptor targeting delivery system based on acid-cleavage hydrazone bond was developed in the study. The characters of CMCS-hyd-CUR-EGFR-mAb were identified. The in vitro release studies revealed that this drug delivery system was acid-sensitive, and the self-assembled nanoparticles which were spherical. The in vitro results indicated that the dual-receptor targeting nanoparticles could be faster internalized into the Cal-27 cells via receptor-mediated endocytosis, which exhibited better antitumor activity than the one-receptor nanoparticles. The experimental results clearly reveal that CMCS-hyd-CUR-EGFR mAb provides a novel way for drug delivery in oral cancer treatment.展开更多
Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assem...Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.展开更多
In this work, novel nanostructured core-shell poly(ethylene glycol) (PEG)-polyhedral oligosilsesquioxane (POSS) nanoparticles were used to encapsulate insulin as new drug delivery carriers. The morphologies, particle ...In this work, novel nanostructured core-shell poly(ethylene glycol) (PEG)-polyhedral oligosilsesquioxane (POSS) nanoparticles were used to encapsulate insulin as new drug delivery carriers. The morphologies, particle size and ζ potential of the pure nanostructured core-shell PEG-POSS and the corresponding insulin-loaded PEG-POSS nanoparticles were investigated by transmission electron microscopy (TEM) and laser diffraction particle sizer. TEM analysis demonstrated that pure and insulin-loaded self-assembled PEG-POSS nanoparticles were of spherical shape with core-shell nanostructure, and were well-dispersed and uniform in size distribution. Insulin release test showed that insulin was well-protected inside PEG-POSS nanoparticles at gastric pH for 2hrs, and was released at intestinal pH (pH 6-7) where the absorption and activation of the drug are necessary. We therefore believe that such nanostructured PEG-POSS nanoparticles could be useful as a potential carrier for insulin drug delivery systems.展开更多
基金Project supported by the National Key Basic Research Program of China(Grant No.2013CB933903)the National Natural Science Foundation of China(Grant Nos.20974065+2 种基金51173117and 50830107)the Scientific Research Start-up Fund of Kunming University of Science and Technology(Grant No.KKSY201305089)
文摘Recent progress of the preparation and applications of superparamagnetic iron oxide(SPIO) clusters as magnetic resonance imaging(MRI) probes is reviewed with regard to their applications in labeling and tracking cells in vivo, in diagnosis of cardiovascular diseases and tumors, and in drug delivery systems. Magnetic nanoparticles(NPs), especially SPIO nanoparticles, have long been used as MRI contrast agents and as an advantageous nanoplatform for drug delivery,taking advantage of their unique magnetic properties and ability to function at the molecular and cellular levels. Due to advances in nanotechnology, various means to control SPIO NPs' size, composition, magnetization and relaxivity have been developed, as well as ways to usefully modify their surface. Recently, self-assembly of SPIO NP clusters in particulate carriers — such as polymeric micelles, vesicles, liposomes, and layer-by-layer(Lb L) capsules — have been widely studied for application as ultrasensitive MRI probes, owing to their remarkably high spin–spin(T2) relaxivity and convenience for further functionalization.
基金Project supported by the National Natural Science Foundation of China (Grant No 10334060) and The State Key Development Program for Basic Research of China (Grant No 2005CB623602).
文摘Arrays of noble metal nanoparticles show potential applications in (bio-)sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and interparticle spacing of the nanoparticles is very important. Here, we combine seed-mediated growth with nanosphere lithography to study the controllable growth of gold nanoparticles (Au NPs), in which the self-assembly monolayer of polystyrene (PS) on a silicon surface is used to guide the modification of allaunesilanes and the subsequent adsorption of gold seeds; seed-mediated growth is applied to controlling the morphology and size of Au NPs. The size of adsorption region (determining the number of adsorbed gold seeds) is controlled by etching PS microspheres with oxygen plasma or annealing PS microspheres at the glass transition temperature. The size and morphology of the Au NPs are controlled by changing growth conditions. In such a way, we have achieved the dual control of the obtained Au NPs. Preliminary results show that this strategy holds a great promise. This approach can also be extended to a wide range of materials and substrates.
基金Funded by the National Natural Science Foundation of China(No.50973088)
文摘Nanoparticles conjugated with antibody were designed as active drug delivery system to reduce the toxicity and side effects of drugs for acute myeloid leukemia(AML).Moreover,methotrexate(MTX)was chosen as modeldrug and encapsulate within folic acid modified carboxymethylchitosan(FACMCS)nanoparticles through self-assembling.The chemicalstructure,morphology,release and targeting of nanoparticles were characterized by routine detection.It is demonstrated that the mean diameter is about 150 nm,the release rate increases with the decreasing of p H,the binding rate of CD33 antibody and FA-CMCS nanoparticles is about 5:2,and nanoparticles can effectively bind onto HL60 cells in vitro.The experimentalresults indicate that the FA-CMCS nanoparticles conjugated with antibody may be used as a potentialp Hsensitive drug delivery system with leukemic targeting properties.
基金Funded by the Tianjin Research Program of Applied Basic & Cutting-edge Technologies (No.09JCYBJC27200)
文摘With a two-phase method,well-dispersed 5.2 nm Ag nanoparticles with narrow size distribution (±0.5 nm) are synthesized.The assembled structures of colloidal Ag nanoparticles on highly oriented pyrolytic graphite (HOPG),silicon chip and microscopic glass have been investigated by atomic force microscopy (AFM).With different spin-coating speeds and concentrations of colloidal silver nanoparticles,various assembly structures could form on those substrates.On HOPG,Ag nanoparticles were absorbed and aligned along single-atom-height step edges to form a linear one-layer structure.And on silicon chip and microscopic glass,one-layer closed packing fractal structure and two-layer closed packing ring were observed respectively.
文摘Forming a monolayer of mixed nickel and gold nanoparticles through self-assembly via simple solution processing constitutes an important step toward inexpensive nanoparticle-based carbon nanofiber growth.In this work,mixed gold and nickel nanoparticles were anchored on the silicon wafer using self-assembled monolayers(SAMs)as a template.SAMs of 3-mercaptopropyl trimethoxysilane(MPTS-SAMs)were formed on silicon wafer,with the exposed thiol functionality providing ligand exchange sites to form the mixed monolayer of nickel and gold nanoparticles via a two-step sequential soaking approach.The densities of the nickel and gold nanoparticles on the surface can be varied by adjusting the soaking sequence.
基金supported by National Natural Science Foundation of China (No. 51373168)
文摘Combretastatin A4(CA4) possesses varying ability to cause vascular disruption in tumors,while the short half-life, low water solubility and deactivation of many CA4 analogs during storage limited its antitumor efficacy and drug stability. A novel macromolecular conjugate of CA4(CA4-PL) was synthesized by covalent bonding of CA4 onto poly(L-glutamic acid)-graft-polyethylene glycol(PLG-g-PEG) via Yamaguchi reaction. The obtained CA4-PL was characterized by ~1H NMR, GPC, and UV methods, and the properties of the nanoparticles composed of CA4-PL, including critical aggregation concentration, size and size distribution, and morphology, were investigated. CA4-PL can self-assemble to form micelle-like nanoparticles of 80~120 nm in diameter, which may have potential to improve the blood circulation period as well as the targetability of CA4, and find applications to treat various tumors when combined with traditional chemotherapy or radio therapy.
基金Supported by the project from Science and Technology Department of Zhejiang Province (2003C11027)
文摘Zirconia nanoparticles were synthesized via hydrothermal method without any additives. This work focuses on the effect of preparation conditions1 such as the precursor preparation condition and crystallization time of nanocrystallite in autoclave on the properties of as-prepared products. The results indicated that the amount of tetragonal zirconia varied with the preparation conditions. It increased with the increase of the concentration of KOH solution in precursor producing process and reduced with the prolongation of crystallization time. At the same time, the particle size and morphology were also affected by the preparation conditions. In addition, the self-assembled spindle- like aggregates were observed in present works.
基金supported by the National Natural Science Foundation of China(10972121)the Ministry of Education (SRFDP 20090002110047)the 973 Program of MOST(2012CB934101)
文摘Self-assembled nanostructures of lipids and nanoparticles hold great promise for applications in such fields as nanomedicine. This paper uses the self-consistent field theory to investigate the self-assembly behavior of lipid molecules and nanoparticles with different shapes in an aqueous solution. It is found that the lipid molecules can form monolayered and bilayered nanostructures around the nanopartieles with different shapes (e.g., triangular, square, hexagonal and octangular). With decreasing the size of nanoparticles or increasing the number of polygon edges, the shape of lipid layers will approach an approximately spherical shape. These findings may help to predict and design novel drug delivery nanocarriers.
基金the Natural Science Foundation of Jiangsu Province(No.BK2011024)the Scientific Research Project of Chaohu College(No.XLZ-200902)
文摘The formation of Ag clusters on titanium oxide (TiO2) nanoparticles was achieved by self-assembly process and calcination. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and ultraviolet visible spectroscopy (UV-Vis), and conventional techniques (XRD, TEM and UV-Vis) were used to identify Ag particles on the TiO2 surfaces. The results show that Ag-TiO2 particles can be applied to improve catalytic activity of the epoxidation of styrene oxides. Styrene oxide is the main product of catalytic reaction with H2O2 as the oxidant by using Ag-TiO2 nanoparticles as catalysts. High catalytic activitity of styrene oxide can be obtainable at 80 ℃. The reaction temperature, reaction time, the molar ratio of H2O2/styrene and solvent affect greatly the catalytic epoxidation of styrene.
基金the financial support of the Natural Science Foundation of China(52003070)Zhejiang Provincial Natural Science Foundation of China(LR20E030003).
文摘Comprehensive Summary Metal nanoparticles(NPs)decorated block copolymer(BCP)hybrid nanoparticles have attracted enormous attention for their actual value in catalysis,medical therapy,and bioengineering.The confined assembly of BCPs within evaporative emulsion droplet is verified as an effective method to provide polymeric scaffolds to load metal NPs.However,to date,it remains challenging to generate different types of metal NPs decorated BCP hybrid nanoparticles.Herein,we employed the emulsion confined self-assembly of poly(styrene-b-2-vinylpyridine)(PS-b-P2VP)and the followed seed-mediated growth of Au and palladium(Pd)NPs onto well-defined BCP particles to design a series of Au/Pd decorated BCP hybrid nanoparticles,which exhibited excellent catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with the reductant of NaBH4.This work may inspire more researchers to investigate the selective decoration of different metal NPs onto the polymeric scaffolds,broadening the potential applications of the inorganic/organic hybrid nanoparticles.
基金the National Basic Research program of China (No.2005CB623903).
文摘A novel pH-sensitive nanoparticle drug delivery system (DDS) derived fl om natural polysaccharide pullulan for doxorubicin (DOX) release was prepared.Pullulan was functionalized by successive carboxymethylization and amidation to introduce hydrazide groups.DOX was then grafted onto pullulan backbone through the pH-sensitive hydrazone bond to form a pullulan/DOX conjugate.This conjugate self-assembled to form nano-sized particles in aqueous solution as a result of the hydrophobic interaction of the DOX.Trans...
基金Funded by the National Natural Science Foundation of China(Nos.51873167 and 50803048)
文摘A novel method was presented to create composite micelles of amphiphilic copolymers and Ag nanoparticles(NPs) in a three-dimensional co-flow focusing microfluidic device(3D CFMD). Self-assembly of the copolymers was initiated by the fast mixing of water and a blend dispersion of hydrophobic Ag NPs and amphiphilic copolymers. At the same time, the hydrophobic Ag NPs enter the core of copolymer micelles, based on the hydrophobic interaction. The copolymer-Ag NPs composite micelles have a core-shell structure with copolymer shell and Ag NPs core. COMSOL Multiphysics is used to simulate the concentration distribution of copolymers and Ag NPs under different flow rates. Co-assembly microfluidic conditions are determined based on simulation results. Under suitable microfluidic conditions, both block copolymers and gradient copolymers can co-assemble with hydrophobic Ag NPs to form composite micelles, respectively. This microfluidic coassembly method will have a good prospect in the preparation of composite micelles of amphiphilic copolymers and metal nanoparticles.
文摘This study compared a new type of polysaccharide-coated magnetic nanoparticles (in which the polysaccharide is derived from Angelica sinensis) with the dextran magnetic nanoparticles in terms of preparation, biocompatibility and tissue distribution in vivo and in vitro in order to examine the potential application of Angelica polysaccharide as a novel carrier in magnetic drug targeting (MDT). Magnetic nanoparticles were prepared by chemical co-precipitation. Their physical and chemical properties were determined by using the transmission electron microscope (TEM), laser particle size analyzer (DLS) and vibrating sample magnetometer (VSM), and their purity and structure by using X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). The atomic absorption spectrometric method was performed for quantification of the iron content in different tissues. Histological sections were stained by Prussian blue staining to observe the disposition of magnetic nanoparticles in the liver and kidney. The results showed that both kinds of magnetic nanoparticles possessed small particle size, good dispersion and good magnetic properties. XRD showed the main component of the two magnetic nanoparticles was Fe3O4 crystals, and FTIR proved Fe3O4 was successfully coated by each polysaccharide, respectively. In vivo, Fe3O4-dextran accumulated in the liver, spleen and lung and Fe3O4-Angelica polysaccharide only in the spleen and lung. It was concluded that Angelica polysaccharide may be applied as a novel carrier in the preparation of magnetic nanoparticles.
基金Supported by the National Natural Science Foundation of China(No.2 0 0 730 2 8) and the Key L aboratory of ModernOptical Technologies in Suzhou U niversity
文摘CdS nanoparticles were assembled on the smooth surface of a piece of silver by using 1,4-benzenedithiol as coupling molecules. The SEM and resonance Raman spectroscopic characterizations demonstrate that the nanosized structure of CdS was still preserved upon assembly, and a two-dimensional structure of CdS nanoparticles was formed on the substrate surface. The FT-Raman spectra indicate that 1,4-benzenedithiol was coupled between CdS nanoparticles and the silver surface with a tilted orientation. The Raman scattering of 1,4-benzenedithiol was substantially enhanced by the assembled CdS nanoparticles, probably due to the alteration of the polarizability of 1,4-benzenedithiol and the electromagnetic interaction between the dipoles of the CdS particle with its image in the metal substrate.
基金The authors thank the support by the National Natural Science Foundation of China (No.60171005, No.6037107 and No.90406023)Promotional Foundation of Ministry of Education of China for excellent youth teachers (2000) Grant-in-aid for Returnee in City of Nanjing, China.
文摘A novel strategy has been developed for construction of nanoparticle chains between nanoelectrodes with bifunctional molecules by taking advantage of linear aggregation of colloidal particles in organis solvents. As confirmed by scanning electron microscopy (SEM),an individual nanoparticle chain bridged the electrode pair. The present approach makes this technique to be cheap and may be applicable in microelectronic industry.
基金supported by the National Natural Science Foundation of China(Grant No.11174222)the National Basic Research Program of China(Grant No.2011CB922203)
文摘The intrinsic dynamics of two interacting electric polarized nanorods is theoretically investigated. The relative motion between them caused by electric dipole-dipole interaction is derived based on the generalized Lagrangian formulation. The results show that the relative translation and rotation are nonlinear and closely dependent on the initial configuration of the two nanorods. Furthermore, the general conditions of the initial configuration, which determine the two nanorods to repel or attract each other at the initial time, are obtained. The two-dimensional relative motion of the two nanorods shows that the antiparallel and head-to-tail ordering stable self-assembly are respectively formed in two planar initial configurations. For different three-dimensional initial configurations, the interesting dynamic relative attraction, repulsion, and oscillation with rotation are respectively realized. Finally, the theoretical schemes which realize the relaxing, direct head-to-tail ordering, and direct antiparallel ordering stable self-assembly are presented according to the different modes of the motion of the nanoparticles. Some of our results agree well with the results of experiments and simulations.
基金Funded by the National Natural Science Foundation of China(Nos.81771080 and 8131147)the Opening Project of Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients(No.HLPAI 2014006)the Health Commission of Hubei Province Scientific Research Project(No.WJ2019H275)
文摘A dual-receptor targeting delivery system based on acid-cleavage hydrazone bond was developed in the study. The characters of CMCS-hyd-CUR-EGFR-mAb were identified. The in vitro release studies revealed that this drug delivery system was acid-sensitive, and the self-assembled nanoparticles which were spherical. The in vitro results indicated that the dual-receptor targeting nanoparticles could be faster internalized into the Cal-27 cells via receptor-mediated endocytosis, which exhibited better antitumor activity than the one-receptor nanoparticles. The experimental results clearly reveal that CMCS-hyd-CUR-EGFR mAb provides a novel way for drug delivery in oral cancer treatment.
基金This work is supported by the National Natural Science Foundation of China (Grant No. 90307014).
文摘Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.
文摘In this work, novel nanostructured core-shell poly(ethylene glycol) (PEG)-polyhedral oligosilsesquioxane (POSS) nanoparticles were used to encapsulate insulin as new drug delivery carriers. The morphologies, particle size and ζ potential of the pure nanostructured core-shell PEG-POSS and the corresponding insulin-loaded PEG-POSS nanoparticles were investigated by transmission electron microscopy (TEM) and laser diffraction particle sizer. TEM analysis demonstrated that pure and insulin-loaded self-assembled PEG-POSS nanoparticles were of spherical shape with core-shell nanostructure, and were well-dispersed and uniform in size distribution. Insulin release test showed that insulin was well-protected inside PEG-POSS nanoparticles at gastric pH for 2hrs, and was released at intestinal pH (pH 6-7) where the absorption and activation of the drug are necessary. We therefore believe that such nanostructured PEG-POSS nanoparticles could be useful as a potential carrier for insulin drug delivery systems.