In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)co...In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)core and a surface coating of lipid monolayer.Membrane emulsification technique was used to obtain uniform-sized Lipid NPs.Ovalbumin(OVA)was used as a model vaccine.Compared with the pure PLGA NPs,the Lipid NPs achieved higher loading capacity(LC)and entrapment efficiency(EE)for the encapsulated OVA.An in vitro oral release profile showed that the OVA-Lipid NPs were with lower initial burst and could protect the loaded OVA from the harsh gastrointestinal(GI)environment for a long time.In addition,a human microfold cell(M-cell)transcytotic assay demonstrated that due to a lipid layer structure on the particle surface,the Lipid NPs showed higher affinity to the M-cells.Since the M-cell in the intestinal epithelium played an important role in particle transportation as well as intimately associated with the underlying immune cells,the OVA-Lipid NPs effectively induced mucosal and humoral immune responses.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
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
An effective vaccine against group A streptococcus(GAS)is highly desirable for definitive control of GAS infections.In the present study,two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were devel...An effective vaccine against group A streptococcus(GAS)is highly desirable for definitive control of GAS infections.In the present study,two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were developed.The vaccines were primarily composed of encapsulated KLH protein(a source of T helper cell epitopes)and lipidated M-protein derived B cell peptide epitope(lipoJ14)within the amphiphilic structure of nanoparticles.The only difference between themwas one of the nanoparticles vaccines received additional surface coating with poly(I:C).The formulated vaccines exhibited nanosized particles within the range of 220–240 nm.Cellular uptake study showed that nanoparticles vaccine without additional poly(I:C)coating has greater uptake by dendritic cells and macrophages compared to nanoparticles vaccine that was functionalized with poly(I:C).Both vaccines were found to be safe in mice and showed negligible cytotoxicity against HEK293 cells.Upon immunization in mice,both nanoparticle vaccines produced high antigen-specific antibodies titres that were regulated by a balanced Th1 and Th2 response compared to physical mixture.These antibodies elicited high opsonic activity against the tested GAS strains.Overall,our data demonstrated that amphiphilic chitosan nanoparticles platform induced a potent immune response even without additional inclusion of poly(I:C).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
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
Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of anti...Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.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
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
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
Tumor immunotherapy is a rapidly emerging form of cancer treatment. In the current study, a nanoparticle-based vaccine was constructed and the efficacy was assessed through analysis of immune cell populations, tumor g...Tumor immunotherapy is a rapidly emerging form of cancer treatment. In the current study, a nanoparticle-based vaccine was constructed and the efficacy was assessed through analysis of immune cell populations, tumor growth rates, and metastasis. The vaccine was fabricated through encapsulation of plasmid DNA encoding the tumor-associated antigen Mage-b, and the TLR9 agonist CpG oligodeoxynucleotides by a biodegradable polymer, poly(L,D-lactic-coglycolic acid) (PLGA). The size and shape of the nanoparticles suggested that they were an appropriate size for uptake by professional antigen presenting cells;dendritic cells. Furthermore, effects of the immunopotentiating drug cyclo-phosphamide was included to decrease systemic populations of regulatory T cells (Treg);immune system sentinels that down-regulate immune responses. The vaccine was assessed using the 4T1 murine mammary carcinoma model which is a model for stage IV breast cancer. The combined cyclophosphamide/nanoparticle vaccine was shown to significantly reduce 4T1 tumor growth rates and lung metastasis in female BALB/c mice.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
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
mRNA vaccines have emerged as promising alternative platforms to conventional vaccines.Their ease of production,low cost,safety profile and high potency render them ideal candidates for prevention and treatment of inf...mRNA vaccines have emerged as promising alternative platforms to conventional vaccines.Their ease of production,low cost,safety profile and high potency render them ideal candidates for prevention and treatment of infectious diseases,especially in the midst of pandemics.The challenges that face in vitro transcribed RNA were partially amended by addition of tethered adjuvants or co-delivery of naked mRNA with an adjuvanttethered RNA.However,it wasn’t until recently that the progress made in nanotechnology helped enhance mRNA stability and delivery by entrapment in novel delivery systems of which,lipid nanoparticles.The continuous advancement in the fields of nanotechnology and tissue engineering provided novel carriers for mRNA vaccines such as polymeric nanoparticles and scaffolds.Various studies have shown the advantages of adopting mRNA vaccines for viral diseases and cancer in animal and human studies.Self-amplifying mRNA is considered today the next generation of mRNA vaccines and current studies reveal promising outcomes.This review provides a comprehensive overview of mRNA vaccines used in past and present studies,and discusses future directions and challenges in advancing this vaccine platform to widespread clinical use.展开更多
The development of a massively producible vaccine against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,is essential for stopping the current coronavirus disease(COVID-19)pandemic.A v...The development of a massively producible vaccine against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,is essential for stopping the current coronavirus disease(COVID-19)pandemic.A vaccine must stimulate effective antibody and T cell responses in vivo to induce long-term protection.Scientific researchers have been developing vaccine candidates for the severe acute respiratory syndrome(SARS)and Middle East respiratory syndrome(MERS)since the outbreaks of these diseases.The prevalence of new biotechnologies such as genetic engineering has shed light on the generation of vaccines against novel viruses.In this review,we present the status of the development of coronavirus vaccines,focusing particularly on the biomimetic nanoparticle technology platform,which is likely to have a major role in future developments of personalized medicine.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
The self-assembly behavior of the amphiphilic block copolymer poly( methyl methacrylate) -block-poly( lead dimethacrylate) (PMMA-b-PLDMA) with cross-linked hydrophilic block(PLDMA) in ethanol was investigated....The self-assembly behavior of the amphiphilic block copolymer poly( methyl methacrylate) -block-poly( lead dimethacrylate) (PMMA-b-PLDMA) with cross-linked hydrophilic block(PLDMA) in ethanol was investigated. The results show that the size and morphology of the resulting micelle or micellar aggregates are ascribed to the content of ethanol and the nature of the solvent mixture. PbS nanoparticles were formed in the micelle by in situ reaction with H2S gas. The morphology and size of the self-assembly objects were investigated using scanning electron microscopy (SEM) and transmission electron microscopy(TEM).展开更多
基金This work was financially supported by the 973 Program(Grant No.2009CB930300)National Natural Science Foundation of China(No.81273449).
文摘In this study,a polymeric lipid nanoparticle(NP)(simplified as Lipid NP)was reported as a promising oral vaccine delivery system.The Lipid NPs composed of a hydrophobic polymeric poly(D,L-lactide-co-glycolide)(PLGA)core and a surface coating of lipid monolayer.Membrane emulsification technique was used to obtain uniform-sized Lipid NPs.Ovalbumin(OVA)was used as a model vaccine.Compared with the pure PLGA NPs,the Lipid NPs achieved higher loading capacity(LC)and entrapment efficiency(EE)for the encapsulated OVA.An in vitro oral release profile showed that the OVA-Lipid NPs were with lower initial burst and could protect the loaded OVA from the harsh gastrointestinal(GI)environment for a long time.In addition,a human microfold cell(M-cell)transcytotic assay demonstrated that due to a lipid layer structure on the particle surface,the Lipid NPs showed higher affinity to the M-cells.Since the M-cell in the intestinal epithelium played an important role in particle transportation as well as intimately associated with the underlying immune cells,the OVA-Lipid NPs effectively induced mucosal and humoral immune responses.
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 financially by Universiti Kebangsaan Malaysia(UKM),Malaysia[DCP-2017-003/2].
文摘An effective vaccine against group A streptococcus(GAS)is highly desirable for definitive control of GAS infections.In the present study,two variants of amphiphilic chitosan nanoparticles-based GAS vaccines were developed.The vaccines were primarily composed of encapsulated KLH protein(a source of T helper cell epitopes)and lipidated M-protein derived B cell peptide epitope(lipoJ14)within the amphiphilic structure of nanoparticles.The only difference between themwas one of the nanoparticles vaccines received additional surface coating with poly(I:C).The formulated vaccines exhibited nanosized particles within the range of 220–240 nm.Cellular uptake study showed that nanoparticles vaccine without additional poly(I:C)coating has greater uptake by dendritic cells and macrophages compared to nanoparticles vaccine that was functionalized with poly(I:C).Both vaccines were found to be safe in mice and showed negligible cytotoxicity against HEK293 cells.Upon immunization in mice,both nanoparticle vaccines produced high antigen-specific antibodies titres that were regulated by a balanced Th1 and Th2 response compared to physical mixture.These antibodies elicited high opsonic activity against the tested GAS strains.Overall,our data demonstrated that amphiphilic chitosan nanoparticles platform induced a potent immune response even without additional inclusion of poly(I:C).
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supported by Scientific and Technological Research Council of Turkey(TUBITAK,Grant No.213S148)
文摘Objective: To prepare and characterize poly lactic-co-glycolic acid(PLGA) nanoparticles loaded with soluble leishmanial antigen or autoclaved leishmanial antigen and explore in vitro and in vivo immunogenicity of antigen encapsulated nanoparticles. Methods: Water/oil/water double emulsion technique was employed to synthesize PLGA nanoparticles, and scanning electron microscopy, Fourier transform infrared spectroscopy and Zeta-potential measurements were used to identify the characteristics of nanoparticles. Cytotoxicity of synthetized nanoparticles on J774 macrophage were investigated by MTT assays. To determine the in vitro immunostimulatory efficacies of nanoparticles, griess reaction and ELISA was used to measure the amounts of NO and cytokines. During the in vivo analysis, Balb/c mice were immunized with vaccine formulations, and protective properties of nanoparticles were measured by Leishman Donovan unit in the liver following the infection. Cytokine levels in spleens of mice were determined by ELISA. Results: MTT assay showed that neither soluble leishmanial antigen nor autoclaved leishmanial antigen encapsulated nanoparticles showed cytotoxicity against J774 macrophage cells. Contrary to free antigens, both autoclaved leishmanial antigen-nanoparticle and soluble leishmanial antigen-nanoparticle formulations led to a 10 and 16-fold increase in NO amounts by macrophages, respectively. Leishman Donovan unit calculations revealed that soluble leishmanial antigen-nanoparticles and autoclaved leishmanial antigen-nanoparticles yielded 52% and 64% protection against visceral leishmaniasis in mouse models. Besides, in vitro and in vivo tests demonstrated that by increasing IFN-γ and IL-12 levels and inhibiting IL-4 and IL-10 secretions, autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigennanoparticles triggered Th1 immune response. Conclusions: Both autoclaved leishmanial antigen-nanoparticles and soluble leishmanial antigen-nanoparticles formulations provide exceptional in vitro and in vivo immunostimulatory activities. Hence, PLGA-based antigen delivery systems are recommended as potential vaccine candidates against visceral leishmaniasis.
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.
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.
文摘Tumor immunotherapy is a rapidly emerging form of cancer treatment. In the current study, a nanoparticle-based vaccine was constructed and the efficacy was assessed through analysis of immune cell populations, tumor growth rates, and metastasis. The vaccine was fabricated through encapsulation of plasmid DNA encoding the tumor-associated antigen Mage-b, and the TLR9 agonist CpG oligodeoxynucleotides by a biodegradable polymer, poly(L,D-lactic-coglycolic acid) (PLGA). The size and shape of the nanoparticles suggested that they were an appropriate size for uptake by professional antigen presenting cells;dendritic cells. Furthermore, effects of the immunopotentiating drug cyclo-phosphamide was included to decrease systemic populations of regulatory T cells (Treg);immune system sentinels that down-regulate immune responses. The vaccine was assessed using the 4T1 murine mammary carcinoma model which is a model for stage IV breast cancer. The combined cyclophosphamide/nanoparticle vaccine was shown to significantly reduce 4T1 tumor growth rates and lung metastasis in female BALB/c mice.
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support received from American University of Beirut(AUB)for their support and encouragement in carrying out this work.
文摘mRNA vaccines have emerged as promising alternative platforms to conventional vaccines.Their ease of production,low cost,safety profile and high potency render them ideal candidates for prevention and treatment of infectious diseases,especially in the midst of pandemics.The challenges that face in vitro transcribed RNA were partially amended by addition of tethered adjuvants or co-delivery of naked mRNA with an adjuvanttethered RNA.However,it wasn’t until recently that the progress made in nanotechnology helped enhance mRNA stability and delivery by entrapment in novel delivery systems of which,lipid nanoparticles.The continuous advancement in the fields of nanotechnology and tissue engineering provided novel carriers for mRNA vaccines such as polymeric nanoparticles and scaffolds.Various studies have shown the advantages of adopting mRNA vaccines for viral diseases and cancer in animal and human studies.Self-amplifying mRNA is considered today the next generation of mRNA vaccines and current studies reveal promising outcomes.This review provides a comprehensive overview of mRNA vaccines used in past and present studies,and discusses future directions and challenges in advancing this vaccine platform to widespread clinical use.
基金This work was supported by the Fundamental Research Funds for the Central Universities(No.2042020kf1015)National Natural Science Foundation of China(No.81672114,81702627)the Medical talented youth development project in the Health Commission of Hubei Province(No.WJ2019Q049).
文摘The development of a massively producible vaccine against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus,is essential for stopping the current coronavirus disease(COVID-19)pandemic.A vaccine must stimulate effective antibody and T cell responses in vivo to induce long-term protection.Scientific researchers have been developing vaccine candidates for the severe acute respiratory syndrome(SARS)and Middle East respiratory syndrome(MERS)since the outbreaks of these diseases.The prevalence of new biotechnologies such as genetic engineering has shed light on the generation of vaccines against novel viruses.In this review,we present the status of the development of coronavirus vaccines,focusing particularly on the biomimetic nanoparticle technology platform,which is likely to have a major role in future developments of personalized medicine.
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.
基金Suppored by the National Natural Science Foundation of China ( Nos 20374024 and 20534040) and the Program forChangjiang Scholars and Innovative Research Team in Universities(No IRT0422)
文摘The self-assembly behavior of the amphiphilic block copolymer poly( methyl methacrylate) -block-poly( lead dimethacrylate) (PMMA-b-PLDMA) with cross-linked hydrophilic block(PLDMA) in ethanol was investigated. The results show that the size and morphology of the resulting micelle or micellar aggregates are ascribed to the content of ethanol and the nature of the solvent mixture. PbS nanoparticles were formed in the micelle by in situ reaction with H2S gas. The morphology and size of the self-assembly objects were investigated using scanning electron microscopy (SEM) and transmission electron microscopy(TEM).