The preparation of self-assembling organomodified Co/Al-layered double hydroxide(LDH)via one-step route was studied. A common surfactant,sodium dodecylbenzenesulfonate(DBS),was employed as an organic modifier.The beha...The preparation of self-assembling organomodified Co/Al-layered double hydroxide(LDH)via one-step route was studied. A common surfactant,sodium dodecylbenzenesulfonate(DBS),was employed as an organic modifier.The behavior and structure of self-assembled intercalated organic Co/Al-LDH were investigated by FTIR,SEM,WAXS,element analysis and TGA.Based upon the WAXS results and calculation by Bragg equation,the interlayer distance(d value)for organic Co/Al-LDH is enlarged from 0.75 nm to 3.10 nm,showing that the self-assembling behavior has been carried out successfully.Considering the observation from SEM, the product shows the morphology of organic Co/Al-LDH of a layered structure.In addition,FTIR,element analysis and TGA analysis show that the modifier is intercalated into the gallery of the Co/Al-LDH.Since organic modification for nanofiller is deemed to be necessary before applying it into polymer,the successful preparation of organomodified Co/Al-LDH will be significantly beneficial to the preparation and investigation of novel polymer/LDH nanocomposite.展开更多
The inorganic antimicrobial material was inhibited to the microbes with the added metal ion,Zn.The primary wet product carrying 5%-10% zinc ion was generated under the following conditions：temperature was 95 ℃,solut...The inorganic antimicrobial material was inhibited to the microbes with the added metal ion,Zn.The primary wet product carrying 5%-10% zinc ion was generated under the following conditions：temperature was 95 ℃,solution zinc concentration was 1.2-2.0 mol/L,and the ratio of Zn solution to zeolite weight was 5：1.The final stable product was manufactured after baking in an oven for 1-3 h at the temperature of 500-900 ℃.The baked material was tested for its disinfection effectiveness and coloring effect when mixed with paint coating.Based on the final batch of tests,the zinc content of this anti-microbial product was further optimized.展开更多
Four coumarin derivatives（4a-4d） with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organ...Four coumarin derivatives（4a-4d） with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formation of the organogels of compound 4d besides H-bonding and van der Waals interaction, which were the driving forces for the self-assembling of compound 4c in gel state. The gel of compound 4d in toluene could emit strong fluorescence under UV irradiation and the [2＋2] cyclo-addition was suggested by ^1H NMR and fluorescence spectroscopy. This light-sensitive organogel might find application in optical materials.展开更多
Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-bu...Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer’s disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications.展开更多
The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by so...The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group （P〈0.05）. Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group （P〈0.01）. ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group＇s PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated （P〈0.01）. The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.展开更多
In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-...In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.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
Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To ...Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.展开更多
By covalently binding chromophore NPP, N-(4-nitrophenyl)-(L)-prolinol, to a structurally controlled cage-like cross-linking polymer (SCCP), a modified nonlinear optical (NLO) polymeric film prepared by 'in situ po...By covalently binding chromophore NPP, N-(4-nitrophenyl)-(L)-prolinol, to a structurally controlled cage-like cross-linking polymer (SCCP), a modified nonlinear optical (NLO) polymeric film prepared by 'in situ poling and sol-gel' process successfully overcame the fundamental problem of NPP chromophores subliming out from the cages of the 'doped'' NLO polymeric film when heated or placed under UV light. Its d(33) (coefficient of second harmonic generation) is 2.0 X 10(-8) esu. measured by IR dichroism. The modified film has a low decay of the SHG signal and preserves 94% of the initial value after 50 days at room temperature These properties match that of the 'doped' film, indicating that the modified film also retains the main advantages of the 'doped' film.展开更多
A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by...A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by electrochemical and spectroscopic techniques. Results showed that the immobilized HRP exhibited direct electrochemical behavior toward the reduction of H2O2. The resulting biosensor shows a fast amperometric response (<2 s) to H2O2. The linear response range was from 5.0×10-7～1.0×10-5 mol/L with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor has a good reproducibility, and long-term stability.展开更多
A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized b...A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry （DSC）, polarized optical microscope （POM）, and 1 D wide angle X-ray diffraction （WAXD） techniques. In solution, the BP self-assembled into nanoflbers in the mixed dichloromethane and hexane （1：1 volume ratio） solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.展开更多
High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discov...High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discovered for determining the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA).This method is simple,precise and feasible and can be extended to determine the content of low oxidation state in the other transition metal oxide nanomaterials.展开更多
The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functiona...The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functionalized solution for introducing the OH- and groups, and then the heparin was immobilized on the active TiO2 films through the electrostatic self assembly technology. It is shown that the heparinized films are mainly composed of anatase and rutile with smooth and dense surface. In vitro blood compatibility was evaluated by haemolysis test, clotting time and platelet adhesion behavior tests. The results show that the haemocompatibility of the alloy could be significantly improved by surface heparinization.展开更多
Self-assembling molecules are ubiquitous in nature, among which are proteins, nucleic acids (DNA and RNA), peptides and lipids. Recognizing the ability of biomolecules to self-assemble into various 3D shapes at the na...Self-assembling molecules are ubiquitous in nature, among which are proteins, nucleic acids (DNA and RNA), peptides and lipids. Recognizing the ability of biomolecules to self-assemble into various 3D shapes at the nanoscale, researchers are mimicking the self-assembly strategy for engineering of complex nanostructures. However, the general principles underlying the design of self-assembled molecules have not yet been identified. The question is “How to obtain a well-defined shape with desired properties by folding a chain of subunits (such as amino acids and nucleic acids)”, where properties are determined by the precise spatial arrangement of the subunits on the surface. In this paper, we consider the question from the viewpoint of the discrete differential geometry of n-simplices. Self-assembling molecules are then represented as a union of trajectories of 3-simplices (i.e., tetrahedrons), and the question is rephrased as a “boundary value problem” for flows on a space of tetrahedrons. Also considered is a characterization of two types of surface flows of n-simplices. It is a rough classification of surface flows, but may be essential in characterizing important properties of biomolecules such as allosteric regulation. The author believes this paper not only provides a new perspective for the engineering of self-assembling molecules, but also promotes further collaboration between mathematics and other disciplines in life science.展开更多
The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus ...The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus on theeffect of the spacer. The characterization of association behavior of such polymers in water using quasielastic light scattering,capillary electrophoresis, NMR relaxation, various fluorescence, and viscoelastic methods was described. These copolymersform a variety of self-assembled nanostructures depending on the type of the spacer. Random copolymers of AMPS and N-dodecylmethacrylamide show a strong preference for intrapolymer self-association even in concentrated aqueous solutionsforming single-macromolecular self-assemblies (unimolecular micelles). In contrast, random copolymers of AMPS anddodecyl methacrylate are prone to undergo interpolymer associations yielding multipolymer micelles. In random copolymersof AMPS and a methacrylate substituted a nonionic surfactant (HO(CH_2CH_2O)_(25)C_(12)H_(25)) (C_(12)E_(25)), dodecyl groups are muchless restricted by the polymer backbone because they are linked via a long, flexible hydrophilic spacer. Thus, the polymer-bound C_(12)E_(25) surfactant moieties form micelles similar to those formed by discrete surfactants, but they are bridged bypolymer chains forming a network structure.展开更多
pH-sensitive wettability of polystyrene-b-poly（4-vinylpyridine） （PS-b-P4VP） self assembled films, exhibiting superoleophobicity under water and hydrophilicity at low pH value, and oleophobicity under water and hyd...pH-sensitive wettability of polystyrene-b-poly（4-vinylpyridine） （PS-b-P4VP） self assembled films, exhibiting superoleophobicity under water and hydrophilicity at low pH value, and oleophobicity under water and hydrophobicity at neutral condition, has been realized. The wettability properties resulted from the surface topological and chemical transition, which were confirmed by in situ AFM measurements under water at different pH. At low pH, P4VP chains, which were confined in the hexagonal-packed nanodomains, got protonated into a swollen state, while at high pH, P4VP chains were deprotonated into a collapsed state. The reversible protonation/deprotonation procedure on the molecular scale leads to surface topological and chemical transition, thereby pH-sensitive wettability.展开更多
The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedica...The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.展开更多
The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the subst...The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the substrates alternatively in polymer and Tb 3+ ion aqueous solutions. UV-vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X ray photoelectron spectrum (XPS) confirmed the existence of Tb 3+ ion. The pH of both the polymer and TbCl 3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb 3+ ion as well as the ligand indicating the formation of the complex.展开更多
The self-assembled formation of a one-dimensional lanthanum salicylald imine coordination polymer was proved by the X-ray diffraction analysis of new l anthanum(Ⅲ) nitrate complex containing N,N’-bis(salicylidene)-1...The self-assembled formation of a one-dimensional lanthanum salicylald imine coordination polymer was proved by the X-ray diffraction analysis of new l anthanum(Ⅲ) nitrate complex containing N,N’-bis(salicylidene)-1,5-pentanediami ne ligand(H2L) . It was obtained in situ in a one-step,metal-templated condensa tion of salicylaldehyde with 1,5-pentanediamine(cadaverine,biogenic polyamine) and characterized by microanalysis and spectroscopic(IR,ESI-MS,UV-Vis,and 1 H NMR) data. The [La(NO3) 3(μ-H2L) 2]∞ complex displayed 10-coordinate distorted bicapped dodecahedron geometry with unusual coordination pattern of undeprotonat ed salicylaldimines which acted as μ-bridging ditopic ligands using exclusivel y the oxygens as donor atoms with the nitrogen atoms not being involved in the c oordination environment.展开更多
Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can ...Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can drive on the ground, autonomously accomplish self-assembly and then fly in the air coordinately. Mechanical and electrical designs of a DSFR module, as well as the kinematics and dynamics analysis, are specifically investigated. Meanwhile, this paper brings forward a generalized adjacency matrix to describe configurations of DSFR structures. Also, the distributed flight control model is established for vertical taking-off and horizontal hovering, which can be applied to control of DSFR systems with arbitrary configurations. Finally, some experiments are carried out to testify and validate the DSFR design, the autonomous self-assembly strategy and the distributed flight control laws.展开更多
基金Project(50703026)supported by the National Natural Science Foundation of Chinaproject(F/4285-1)supported by International Foundation for Science(IFS)+1 种基金project(20080440182,200902615)supported by China Postdoctoral Science Foundationproject supported by vip-Scientist Research Fellowship granted by Leibniz Institute of Polymer Research Dresden,Germany
文摘The preparation of self-assembling organomodified Co/Al-layered double hydroxide(LDH)via one-step route was studied. A common surfactant,sodium dodecylbenzenesulfonate(DBS),was employed as an organic modifier.The behavior and structure of self-assembled intercalated organic Co/Al-LDH were investigated by FTIR,SEM,WAXS,element analysis and TGA.Based upon the WAXS results and calculation by Bragg equation,the interlayer distance(d value)for organic Co/Al-LDH is enlarged from 0.75 nm to 3.10 nm,showing that the self-assembling behavior has been carried out successfully.Considering the observation from SEM, the product shows the morphology of organic Co/Al-LDH of a layered structure.In addition,FTIR,element analysis and TGA analysis show that the modifier is intercalated into the gallery of the Co/Al-LDH.Since organic modification for nanofiller is deemed to be necessary before applying it into polymer,the successful preparation of organomodified Co/Al-LDH will be significantly beneficial to the preparation and investigation of novel polymer/LDH nanocomposite.
基金Funded by the Construct Plan of Cooperation Project from the Beijing Education Committee(No. XK100080432)
文摘The inorganic antimicrobial material was inhibited to the microbes with the added metal ion,Zn.The primary wet product carrying 5%-10% zinc ion was generated under the following conditions：temperature was 95 ℃,solution zinc concentration was 1.2-2.0 mol/L,and the ratio of Zn solution to zeolite weight was 5：1.The final stable product was manufactured after baking in an oven for 1-3 h at the temperature of 500-900 ℃.The baked material was tested for its disinfection effectiveness and coloring effect when mixed with paint coating.Based on the final batch of tests,the zinc content of this anti-microbial product was further optimized.
基金Sypported by National Natural Science Foundation of China(No.20574027)Program for New Century Excellent Talents in University.
文摘Four coumarin derivatives（4a-4d） with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formation of the organogels of compound 4d besides H-bonding and van der Waals interaction, which were the driving forces for the self-assembling of compound 4c in gel state. The gel of compound 4d in toluene could emit strong fluorescence under UV irradiation and the [2＋2] cyclo-addition was suggested by ^1H NMR and fluorescence spectroscopy. This light-sensitive organogel might find application in optical materials.
基金the Program Funded by the University for Fostering Distinguished Young Scholarsthe National Natural Science Foundation of China(No.51763019,U1832125)+3 种基金the China Postdoctoral Science Foundation(No.2018M630937)the Grassland Talents Program of Inner Mongolia Autonomous Regionthe Distinguished Young Scholars Foundation of Inner Mongolia Autonomous Regionthe Young Leading Talents of Science and Technology Program of Inner Mongolia Autonomous Region
文摘Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer’s disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications.
基金Funded by the National Natural Science Foundation of China (No.30571873)
文摘The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group （P〈0.05）. Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group （P〈0.01）. ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group＇s PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated （P〈0.01）. The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.
基金supported by a grant from the National Key Basic Research Program of China,No.2014CB542202 and 2014CB542205the National Natural Science Foundation of China,No.30973095&81371354+2 种基金a grant from Science and Technology Project of Guangzhou,in China,No.12C32121609the Natural Science Foundation of Guangdong Province of China,No.S2013010014697 to Guo JSHong Kong SCI Fund to Wu WT
文摘In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.
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）.
基金Funded by "Hundreds of Talents Program" of Hubei Province,China
文摘Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.
基金The project was supported by the National Natural Science Foundation of China (No. 59483001).
文摘By covalently binding chromophore NPP, N-(4-nitrophenyl)-(L)-prolinol, to a structurally controlled cage-like cross-linking polymer (SCCP), a modified nonlinear optical (NLO) polymeric film prepared by 'in situ poling and sol-gel' process successfully overcame the fundamental problem of NPP chromophores subliming out from the cages of the 'doped'' NLO polymeric film when heated or placed under UV light. Its d(33) (coefficient of second harmonic generation) is 2.0 X 10(-8) esu. measured by IR dichroism. The modified film has a low decay of the SHG signal and preserves 94% of the initial value after 50 days at room temperature These properties match that of the 'doped' film, indicating that the modified film also retains the main advantages of the 'doped' film.
文摘A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by electrochemical and spectroscopic techniques. Results showed that the immobilized HRP exhibited direct electrochemical behavior toward the reduction of H2O2. The resulting biosensor shows a fast amperometric response (<2 s) to H2O2. The linear response range was from 5.0×10-7～1.0×10-5 mol/L with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor has a good reproducibility, and long-term stability.
基金supported by the National Natural Science Foundation of China(Nos. 51573031 and 51473188)
文摘A self-assembling bis-pyrene （BP） molecule with π-π interactions was designed and synthesized. In condensed state, the BP self-assembled into highly-ordered mesophase at room temperature, which was characterized by using differential scanning calorimetry （DSC）, polarized optical microscope （POM）, and 1 D wide angle X-ray diffraction （WAXD） techniques. In solution, the BP self-assembled into nanoflbers in the mixed dichloromethane and hexane （1：1 volume ratio） solvent. Interestingly, the BP was not fluorescent when dissolved in dichloromethane solution. However, the self-assembled nanostructures of BP in the mixed solvent showed high intensity of green fluorescence. The advantages of self-assembly and fluorescence feature exhibited that BP could be promising fluorescence nanoprobes or nanosensors for various applications.
文摘High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discovered for determining the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA).This method is simple,precise and feasible and can be extended to determine the content of low oxidation state in the other transition metal oxide nanomaterials.
基金Project (31100693/C100302) supported by the National Natural Science Foundation of ChinaProject (31011120049) supported by the Australia-China Special Fund, International Science Linkages Program co-supported by the Department of Innovation, Industry, Science and Research of Australia, and the Ministry of Science and Technology and National Science Foundation of China+1 种基金Project(2010ZDKG-96) supported by the Major Subject of "13115" Programs of Shaan’xi Province, ChinaProject (2012CB619102) supported by the National Basic Research Program of China
文摘The haemocompatibility of Ti-3Zr-2Sn-3Mo-25Nb biomedical alloy was studied after surface heparinization. A layer of sol-gel TiO2 films was applied on the alloy samples followed by active treatment in the bio-functionalized solution for introducing the OH- and groups, and then the heparin was immobilized on the active TiO2 films through the electrostatic self assembly technology. It is shown that the heparinized films are mainly composed of anatase and rutile with smooth and dense surface. In vitro blood compatibility was evaluated by haemolysis test, clotting time and platelet adhesion behavior tests. The results show that the haemocompatibility of the alloy could be significantly improved by surface heparinization.
文摘Self-assembling molecules are ubiquitous in nature, among which are proteins, nucleic acids (DNA and RNA), peptides and lipids. Recognizing the ability of biomolecules to self-assemble into various 3D shapes at the nanoscale, researchers are mimicking the self-assembly strategy for engineering of complex nanostructures. However, the general principles underlying the design of self-assembled molecules have not yet been identified. The question is “How to obtain a well-defined shape with desired properties by folding a chain of subunits (such as amino acids and nucleic acids)”, where properties are determined by the precise spatial arrangement of the subunits on the surface. In this paper, we consider the question from the viewpoint of the discrete differential geometry of n-simplices. Self-assembling molecules are then represented as a union of trajectories of 3-simplices (i.e., tetrahedrons), and the question is rephrased as a “boundary value problem” for flows on a space of tetrahedrons. Also considered is a characterization of two types of surface flows of n-simplices. It is a rough classification of surface flows, but may be essential in characterizing important properties of biomolecules such as allosteric regulation. The author believes this paper not only provides a new perspective for the engineering of self-assembling molecules, but also promotes further collaboration between mathematics and other disciplines in life science.
文摘The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus on theeffect of the spacer. The characterization of association behavior of such polymers in water using quasielastic light scattering,capillary electrophoresis, NMR relaxation, various fluorescence, and viscoelastic methods was described. These copolymersform a variety of self-assembled nanostructures depending on the type of the spacer. Random copolymers of AMPS and N-dodecylmethacrylamide show a strong preference for intrapolymer self-association even in concentrated aqueous solutionsforming single-macromolecular self-assemblies (unimolecular micelles). In contrast, random copolymers of AMPS anddodecyl methacrylate are prone to undergo interpolymer associations yielding multipolymer micelles. In random copolymersof AMPS and a methacrylate substituted a nonionic surfactant (HO(CH_2CH_2O)_(25)C_(12)H_(25)) (C_(12)E_(25)), dodecyl groups are muchless restricted by the polymer backbone because they are linked via a long, flexible hydrophilic spacer. Thus, the polymer-bound C_(12)E_(25) surfactant moieties form micelles similar to those formed by discrete surfactants, but they are bridged bypolymer chains forming a network structure.
基金financially supported by the National Natural Science Foundation of China(No.21204002)Specialized Research Fund for the Doctoral Program of Higher Education(No.20111102120050)+1 种基金Program for New Century Excellent Talents in Universities(2010)the Fundamental Research Funds for the Central Universities
文摘pH-sensitive wettability of polystyrene-b-poly（4-vinylpyridine） （PS-b-P4VP） self assembled films, exhibiting superoleophobicity under water and hydrophilicity at low pH value, and oleophobicity under water and hydrophobicity at neutral condition, has been realized. The wettability properties resulted from the surface topological and chemical transition, which were confirmed by in situ AFM measurements under water at different pH. At low pH, P4VP chains, which were confined in the hexagonal-packed nanodomains, got protonated into a swollen state, while at high pH, P4VP chains were deprotonated into a collapsed state. The reversible protonation/deprotonation procedure on the molecular scale leads to surface topological and chemical transition, thereby pH-sensitive wettability.
基金Supported by National Natural Science Foundation(No.0 5 1730 0 3) Beijing Science and Technology New Star Program(No.H0 10 4 10 0 10 112 ) and Im portant Natural Science Foundation of Beijing(No.2 0 310 0 1) .
文摘The polymerization of amphiphilic self assemblies is a promising method to synthesize nano structured materials with novel properties. These materials have many attractive features for their application in biomedical area and materials science, such as catalysis, separation, surface modification, and therapeutics areas. A general review on the polymerization of lipids and surfactant self assemblies to amphiphilic self assemblies is given in this paper with 49 references. The polymerization and the subsequently resulted structure of lipids in different morphologies are summarized. The polymerization of polymerizable surfactants(surfmers) in emulsion and liquid crystalline phases are also discussed. The potential application of new nano porous materials is briefly described.
文摘The layer by layer complexation technique of polymer and metal ion was successfully utilized to fabricate the ultrathin multilayer film of poly(3 thiophene acetic acid (PTAA) and Tb 3+ ion by dipping the substrates alternatively in polymer and Tb 3+ ion aqueous solutions. UV-vis measurement revealed that the absorbance has linearity with the bilayer number from layer to layer and the X ray photoelectron spectrum (XPS) confirmed the existence of Tb 3+ ion. The pH of both the polymer and TbCl 3 solutions influence the thickness dramatically while the concentration of the solutions is not so sensitive. The luminescent spectrum of the complex film shows the characteristic emission of Tb 3+ ion as well as the ligand indicating the formation of the complex.
基金Project supported by the Polish Ministry of Science and Higher Education (NN204 0317 33)
文摘The self-assembled formation of a one-dimensional lanthanum salicylald imine coordination polymer was proved by the X-ray diffraction analysis of new l anthanum(Ⅲ) nitrate complex containing N,N’-bis(salicylidene)-1,5-pentanediami ne ligand(H2L) . It was obtained in situ in a one-step,metal-templated condensa tion of salicylaldehyde with 1,5-pentanediamine(cadaverine,biogenic polyamine) and characterized by microanalysis and spectroscopic(IR,ESI-MS,UV-Vis,and 1 H NMR) data. The [La(NO3) 3(μ-H2L) 2]∞ complex displayed 10-coordinate distorted bicapped dodecahedron geometry with unusual coordination pattern of undeprotonat ed salicylaldimines which acted as μ-bridging ditopic ligands using exclusivel y the oxygens as donor atoms with the nitrogen atoms not being involved in the c oordination environment.
基金the National High-tech Research and Development Program of China(''863''Program)(No.2012AA041402)National Natural Science Foundation of China(Nos.61175079and51105012)Fundamental Research Funds for the Central Universities (No.YWF-11-02-215)
文摘Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can drive on the ground, autonomously accomplish self-assembly and then fly in the air coordinately. Mechanical and electrical designs of a DSFR module, as well as the kinematics and dynamics analysis, are specifically investigated. Meanwhile, this paper brings forward a generalized adjacency matrix to describe configurations of DSFR structures. Also, the distributed flight control model is established for vertical taking-off and horizontal hovering, which can be applied to control of DSFR systems with arbitrary configurations. Finally, some experiments are carried out to testify and validate the DSFR design, the autonomous self-assembly strategy and the distributed flight control laws.
