最新刊期
卷 ， 期 1 ， 2015
- 摘要：A series of photocatalytic composite films were prepared by using anatase titanium sol or P25 type TiO2 powders as photocatalytic materials, and polysiloxane (PDMS) or polyacrylate (PA) as binders.The crystalline phase and dispersion of the two TiO2 particles in organic media (toluene and polymeric matrixes) and photocatalytic degradation of organic matrixes by TiO2 particles were characterized by X-ray diffraction analysis, particle size analysis, field emission scanning electron microscopy, transmission electron microscopy, 3D optical microscopy, weight loss evaluation and UV-Vis spectroscopy, respectively.In addition, photocatalytic activity of PMDS/TiO2 composite films was evaluated by photocatalytic degradation of acid fuchsine 6B under UV irradiation.Titanium sol prepared via sol-gel process was composed of small crystalline grains with a size of about 3 nm, and indeed displayed a higher crystallinity.In comparison to P25 type TiO2, the titanium sol revealed a better compatibility with organic media.They could be uniformly dispersed in organic media without aggregation.Therefore, compared with the composite film with P25 type TiO2, the CC based polymeric matrix was degraded more seriously in the composite films with titanium sol due to their better photocatalytic ability and better dispersion.In contrast, the SiO bonds in the main chain of polysiloxane could resist the strong oxidation of high-energy radicals derived from photocatalytic titaniumsol.Thus, polysiloxane can be used as an ideal photocatalytic organic matrix to load titanium sol, and a kind of composite films with a strong photocatalytic activity and high stability can be obtained.关键词：Polysiloxane;Titanium sol;Composite film;Photocatalysis
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发布时间：2021-03-19 - 摘要：A new approach to self-weld the short carbon fiber (CF) into network throughout the matrix was proposed in this study.It was found that, CF owns strong interactions with nylon 6 (PA6), and adding small amount of PA6 leads to the formation of CF-PA6 networks in the PS matrix, as shown in SEM images and reflected by the platform of storage modulus at higher temperatures.Increasing the contents of PA6 improves the storage modulus at high temperatures, and enhances the strength of the self-welded networks.As a result, the ternary composites behave a remarkable increase in the heat distortion temperature.As carbon fiber possesses superior thermal and electrical conductivity, the composites show a lower electrical percolation threshold and a higher in-plane thermal conductivity.Further analysis demonstrated that the encapsulation of PA6 on the CF surface is a kinetic process, and the storage modulus at 180 ℃ increases linearly with encapsulation ratio of PA6, NPA6.Experimental results confirm that a larger difference in viscosities between PA6 and the matrix is benefit for increasing NPA6, while a longer hot-press time promotes preferential segregation of PA6 on the CF surface and further toward the intersections of CF, and thus greatly improves the mechanical strength of the networks.
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发布时间：2021-03-19 - 摘要：The pH-responsive hyperbranched star copolymers HP(DMAESP-co-BS2MOE)(POEGMA)ns have been successfully synthesized via two-step atom transfer radical polymerization (ATRP).The first step is polymerization of methacryloyloxy-3-thiahexanoyl-N, N-dimethyl acetate (DMAESP) and 2-(2'-bromoisobutyryloxy) ethyl 2-methacryloyl oxyethyl disulfide (BS2MOE).GPC analysis of HP(DMAESP-co-BS2MOE) had a relatively wide molecular weight distribution and showed a double peak, which is consistent with the feature of hyperbranched polymers prepared by self-condensing vinyl polymerization.The resultant HP(DMAESP-co-BS2MOE) was used as macroinitiator in the subsequent ATRP of oligo(ethylene glycol) methacrylate (OEGMA).The molecular weights of the resultant hyperbranched star polymers apparently increased in comparison with HP(DMAESP-co-BS2MOE), but the polydispersity indexes decreased with the increase of polymerization time.In DMAESP, the methacrylate unit and tertiary amine group is linked by an acid-labile -thiopropionate linker, which can be slowly degraded under mild acidic conditions (pH=5.0) to form carboxylic acid terminals, thus the HP(DMAESP-co-BS2MOE)(POEGMA)ns exhibit pH-responsive charge conversion behavior, which is highly favored in gene delivery application.Hyperbranched star copolymers containing disulfide bonds can be further degraded in the presence of glutathione in cytosol.When the hyperbranched star copolymers are self-assembled in water, micelles with the HP(DMAESP-co-BS2MOE) core and the POEGMA shell are formed.Transmission electron microscopy images showed formation of the spherical micelles.The average diameters of the micelles measured by DLS are in the range of 138 to 226 nm, after treated with 10 mmol/L DTT for 24 h, their diameters changed to 21 to 32 nm, and their molecular weights also significantly decreased.The experiments in vitro were performed on HepG2 cells, the micelles formed by HP(DMAESP-co-BS2MOE)(POEGMA)n showed relatively low cytotoxicity comparing to PEI 25K and high DNA loading efficiency.After the internalization of as prepared polyplex, and the charge of the micelles was conversed to negative poly-ion, the efficient release of the loaded DNA was observed, and the micelles can be cleaved by GSH at the same time to further reduce the cyto-toxicity.Therefore, this system shows promising future as gene delivery application.关键词：ATRP;Hyperbranched star copolymer;pH-Sensitive;Gene delivery
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发布时间：2021-03-19 - 摘要：The thermal oxidative aging process of octavinyl-polyhedral oligomeric silsesquioxane (OVPOSS) heated at 180 ℃ in the N2 atmosphere with low oxygen concentration was investigated by series of instrumental analyses.1H-NMR, 13C-NMR, 29Si-NMR were used to analyze the molecular structure before and after this process, while FTIR, MALDI-TOF, ESR, TG-IR, DSC were used to monitor the changes of characteristic groups, molecular weight, active species, mass loss and enthalpy.The method of aging process in the N2 atmosphere with low oxygen concentration would decrease peroxidatic reaction of the double bonds, only to clarify other mechanisms in this process.The experimental results indicated that the double bonds transformed to single bond in this process and C free radical center was verified, as well as the exothermic efficiency, little weight loss and increasing of molecular weight.The conclusion was drawn that the free-radical polymerization exists in thermal oxidative aging process of OVPOSS at low temperature (180 ℃) in the N2 atmosphere with low oxygen concentration.This research may enrich the thermal oxidative aging theory of polyvinylsiloxane.关键词：Octavinyl-polyhedral oligomeric silsesquioxane;Thermal oxidative aging;Free-radical polymerization
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发布时间：2021-03-19 - 摘要：Through the ring-opening polymerization of L-lactide initiated by hydroxyl groups on the surface of HNTs using stannous 2-ethylhexanoate as catalyst, halloysite nanotubes surface-grafted with poly(L-lactic acid) (PLLA) segments (g-HNTs) were synthesized.The compositions and morphologies of the modified and unmodified HNTs were observed by Fourier transformation infrared (FTIR), thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM).Then, a series of PLLA, PLLA/HNTs and PLLA/g-HNTs nanofiber membranes were prepared by electrospinning, the influences of the spinning conditions on the morphologies of the nanofiber membranes were discussed, and the composition, micrograph, interfacial compatibility, tensile properties and cellular compatibility of the composite membranes were studied too.Results showed that the grafting percentage of PLLA segments on the surface of g-HNTs was 14.22% as the molar ratio of HNTs to L-lactide was 1:10.The tubular morphology of HNTs changed little after surface grafting, and g-HNTs can easily disperse in anhydrous ethanol.The voltage and the feed rate have effects on the morphology of fiber membranes, when the voltage was 15 kV and feed rate was 1 mL/h, the diameter of the electrospinning fiber was relatively uniform.The dispersion and interfacial compatibility of g-HNTs in PLLA matrix were superior to those of pristine HNTs, when the content of g-HNTs increased up to 40 wt%, the fiber micrograph of the PLLA/g-HNTs composite membranes continues to remain good, and continuous and relatively uniform fiber can be got.With the content of HNTs and g-HNTs increased, the tensile strength and modulus increased first and then decreased, as the filler content was 5 wt%, the highest tensile strengths and moduli were obtained for both of the PLLA/HNTs and PLLA/g-HNTs composite nanofiber membranes.However, the tensile strength and modulus of the PLLA/g-HNTs composite nanofiber membranes were always higher than those of PLLA/HNTs composite nanofiber membranes at all filler contents due to the good adhesive strength between the g-HNTs and PLLA matrix.The results of 3T3 cells culture in vitro indicated that the cellular compatibility of the PLLA/g-HNTs composite nanofiber membranes is very good, and better than that of pure PLLA and PLLA/HNTs nanofiber membranes.关键词：Poly(L-lactic acid);Halloysite nanotubes;Surface grafting;Electrospinning;Performance
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发布时间：2021-03-19 - 摘要：New amphiphilic triblock copolymer poly(-butyrolactone)-poly(ethylene glycol)-poly(-butyrolactone) (PHB-PEG-PHB) based on poly(-butyrolactone) (PHB) and poly(ethylene glycol) (PEG) was synthesized by anionic ring-opening polymerization of BL initiated with PEG-potassium macroinitiators using tetrahydrofuran as solvent.Many Copolymers with different molecular weight were prepared by adjusting the ratio of monomer (BL) and macroinitiators.Copolymers were characterized by 1H-NMR, 13C-NMR, FTIR, DSC, GPC.The DSC curves showed that amorphous PHB hindered the crystallization of the PEG block.The longer the PHB block length, the more obvious the hindering effect.These PHB-PEG-PHB copolymers were self-assembled into nanoparticles with core-shell structure by a precipitation/solvent evaporation technique in aqueous solutions.These nanoparticles were characterized by SEM and DLS.The nanoparticles size was nanoscale.Their shapes were spherical or square.The size and morphology of nanoparticles were related to the initial concentrations of copolymers.The results showed that the size of nanoparticles reduced with reducing the initial concentrations of copolymers.关键词：Amphiphilic;Triblock polymer PHB-PEG-PHB;Poly(ethylene glycol)-potassium;Naphthalene potassium-crown ether initiator system;Ring-opening copolymerization;Nanoparticles
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发布时间：2021-03-19 - 摘要：Cellulose films with antimicrobial activity and high gas barrier properties are successfully prepared by a facile surface coating chitosan approach.The cellulose wet film was prepared from an ionic liquid (IL), 1-allyl-3-methylimidazolium chloride (AmimCl) by coagulating in water.After that, the cellulose film was immersed in the chitosan-acetic acid solution with different concentrations for 2 h, and then dried in air for 24 h.Via this method, most chitosan was distributed in the surface of cellulose film, which was demonstrated by SEM-EDX, and the film had good hydrophobicity and antimicrobial activity.Scanning electron microscope images indicate that the thickness of chitosan layer on the cellulose films is in the range of 1.31 m to 4.07 m, which can be controlled by the concentration of chitosan.FTIR and TG results demonstrate that there is hydrogen bond interaction between cellulose and chitosan.Besides this, SEM images displayed a homogenous and smooth morphology, indicating a good compatibility between cellulose and chitosan.The optical transmittance of the blend films was maintained well compared with the cellulose lm reaching 80% transmittance at 600~800 nm owing to the low thickness of chitosan layer.Due to the interaction between chitosan and cellulose, the blend films have good mechanical properties, their tensile strengths are greater than 110 MPa.Their oxygen permeability results showed that the blend films had high gas barrier capacity, exceeding the ideal commercial oxygen barrier material ethylene-vinyl acetate copolymer (EVA).The cellulose/chitosan blend films showed effective antimicrobial capability against Staphylococcus aureus examined by the antimicrobial test.The obtained results indicate that the cellulose/chitosan blend films may be suitable for use in the food packaging fields.关键词：Cellulose;Chitosan;Blend film;Coating;Gas barrier;Antimicrobial property
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发布时间：2021-03-19 - 摘要：Gigaporous PS microspheres, prepared in a previous study, were hydrophilized with modified agarose (Agap-PS), and then a thermoresponsive gigaporous bioseparation medium(Agap-PS-PNIPAM)was prepared through a two-step reaction.Bromoacetyl groups were coupled on Agap-PS through acylation to obtain a solid atom transfer radical polymerization (ATRP) initiator (Agap-PS-Br), and poly(N-isopro-pylacrylamide) (PNIPAM) brushes were grafted onto Agap-PS-Br via ATRP afterwards.The effects of ligands, catalysts, solvent and temperature on NIPAM solution ATRP were investigated in detail, and the amount of PNIPAM grafted on Agap-PS-Br reached to 15.07 mg/m2 under optimal conditions.Agap-PS-PNIPAM was characterized by Fourier transform infrared (FTIR) spectra, scanning electron microscope (SEM), mercury porosimetry measurements, laser confocal scanning microscope (LCSM), and protein adsorption experiments.Results showed that thermoresponsive PNIPAM brushes were successfully grafted on the PS microspheres and that the Agap-PS-PNIPAM had good thermo-responsibility.Meanwhile, the gigaporous structure of PS microspheres was well maintained.After modification, nonspecific adsorption of proteins on PS microspheres was greatly reduced.The adsorption amount of bovine serum albumin (BSA) on Agap-PS-PNIPAM at 40 ℃ was 2.69 times to that at 25 ℃ due to the phase transition of PNIPAM brushes from hydrophilicity to hydrophobicity.Flow experiments showed that the Agap-PS-PNIPAM column had low backpressure, good permeability and mechanical stability.Similarily, the bed permeability (K) of Agap-PS-PNIPAM column at 40 ℃ increased by 15.7% than that at 25 ℃ owing to the shrinking of PNIPAM brushes.All results indicate that Agap-PS-PNIPAM has great potentials in green high-speed protein chromatography.关键词：Gigaporous polystyrene microspheres;Hydrophilization;Atom transfer radical polymerization;Thermoresponsive polymer brush;N-isopropylacrylamide
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发布时间：2021-03-19 - 摘要：Chitosan was modified with lipoic acid and nanoparticles thereof were made.By treating the nanoparticles with a catalytic amount of dithiothreitol (DTT), chitosan nanoparticles with disulfide-crosslinkages were obtained.The incorporation of disulfide crosslinkages not only endowed the nanoparticles with reductive-responsive property, but also introduced hydrophobic moiety.Hydrophobic anticancer agent doxorubicin and fluorescent probe fluorescein, respectively, were loaded into the nanoparticles through hydrophobic interactions.The formation of disulfide crosslinkages significantly slowed the release of loaded doxorubicin in a medium without reductive agent (mimicking low reductive environment in blood).In the presence of 10 mmol/L DTT, which mimicked the intracellular high glutathione concentration, doxorubicin released rapidly from the crosslinked nanoparticles because the disulfide crosslinkages were reduced and broken.Flow cytometry assay showed that the cellular uptake of the crosslinked nanoparticles increased when the medium pH deceased from 7.4 (blood and normal tissue pH) to 7.0, 6.8 and 6.5 (mimicking tumor acidic environment).This can be attributed to the neutral and hydrophilic surfaces of the nanoparticles at neutral environment, and the positively charged surfaces at acidic pHs, which was supported by zeta potential data.Cytotocicity assay indicated that doxorubicin-loaded crosslinked nanoparticles showed higher cytotocicity against HeLa cells at pH 6.5 than at pH 7.4.关键词：Chitosan;Disulfide;Doxorubicin;Reductive-responsive;pH-responsive
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发布时间：2021-03-19 - 摘要：In order to reveal the enhancement mechanism of straight chain alcohols on the physicochemical properties of SL, the influences of alcohols on the aggregation structure of SL were investigated by means of zeta potential measurement, laser particle size analyzer and transmission electron microscope(TEM), and the influences of alcohols with different carbon chain lengths on the adsorption characteristics of SL were further studied by using electrostatic layer-by-layer self-assembly, atomic force microscope (AFM) and a quartz crystal microbalance with dissipation monitoring(QCM-D).The results indicated that the hydrocarbon chain of alcohols produced hydrophobic interactions with the hydrophobic core of SL, prompting the carboxyl group wrapped inside to be continuously exposed out so as to increase its negative charge and reduce the degree of aggregation in aqueous solutions.The effects of alcohols with longer carbon chains were more obvious.With the addition of alcohols, the adsorption configuration of SL on solid surface changed from rigid and tight to soft and loose.The adsorption configuration of SL without adding alcohols was mushroom-like structure, of which cation- interaction was the main driving force.The adsorption configuration of SL with adding alcohols turned into polymer brushes, in which electrostatic interaction played an important role, and increased the adsorption amount of SL on solid surface sharply, facilitating the adsorption films more uniform and smooth.关键词：Sodium lignosulfonate;Straight chain alcohols;Aggregate;Adsorption
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发布时间：2021-03-19 - 摘要：Crosslinked proton exchange membranes were prepared based on sulfonated poly(ether ether ketone) (SPEEK) and diamine containing silicon (DMS).The crosslinked structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and dissolution test.Thermal stability, mechanical properties and alternating current impedance measurements of crosslinked proton exchange membranes were conducted by using therogravimetric analyzer (TG), universal material testing machine and electrochemical workstation.Methanol resistance performance, dimensional stability in water, water uptake, ion exchange capacity and proton conductivity were studied in detail.Mechanical properties, methanol resistance performance and dimensional stability of proton exchange membranes were enhanced obviously due to the crosslinking modification.Methanol permeability of SPEEK/DMS-0.5% was reduced from 5.79 10-5 cm2 s-1 to 9.42 10-6 cm2 s-1.Results of scanning electron microscope (SEM) observation showed the well dispersion state of DMS in SPEEK matrix.The properties comparisons were achieved between SPEEK/DMS crosslinked membranes and Nafion-117.The crosslinked proton membranes owned better comprehensive performance compared to Nafion-117.Methanol permeability of SPEEK modified with 20% DMS was 4.26 10-7 cm2 s-1, which was much lower than Nafion-117's 1.88 10-6 cm2 s-1.Moreover, the effective selectivity, tensile strength and Young modulus of SPEEK/DMS-20% crosslinked proton exchange membrane was 1.68, 1.3 and 6.4 times of those of Nafion-117 respectively.关键词：Proton conductivity;Cross linked structure;Sulfonated poly(ether ether ketone);Methanol resistance property
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发布时间：2021-03-19 - 摘要：Considering the salt sensitivity of HPAM and the salt resistance of amphoteric surfactant dodecyl dimethyl betaine, this work explored the effects of the surfactant and inorganic salt concentrations and pH values on the laws of viscosities of the compound systems by using the single factor experiments.The experimental results show that the viscosities of the systems change a little while the concentrations of the amphoteric surfactant are lower than the critical association concentration (CAC), but they increase sharply as the concentrations of the amphoteric surfactant increase above CAC, reach to a peak when the surfactant concentration equals to the polymer saturation concentration (PSP) and decrease with the network structure of the system broken by continuously adding the surfactant.Inorganic salt show a twofold effect on the viscosities of the compound systems, increasing within the low salt concentration and decreasing above the high concentration of salt.At different pH, the salt resistance is presented as alkaline (pH=11.4) acidity (pH=2.8) neutral(pH=7).In order to further explore the effect degree of the concentrations of polymer, amphoteric surfactant and inorganic salt for the system viscosities, this work has done nonlinear regression of the uniform experimental data by using SPSS software, gotten a quantitative relation of the compound system viscosity with three parameters and analyzed their effects on the salt resistance of the compound systems. The theoretical model shows that the polymer concentration is the most important factor, and the effects of the concentrations of amphoteric surfactant and inorganic salt on the system viscosities are similar to those of their single-factors.关键词：Amphoteric surfactant;HPAM;Inorganic salt;pH;Viscosity;Salt resistence;Uniform experiment;Nonlinear regression
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发布时间：2021-03-19 - 摘要：In order to investigate the explicit effects of molecular structures with sterically perpendicular configuration on the general properties of fluorene-based polymers for electroluminescent applications, we designed and synthesized three topology-varied linear copolymers, CSSFX, USSFX and DSSFX.The photophysical properties of the copolymers, thermal stability, energy levels and light-emitting properties of annealed thin solid film under different environments were further illustrated step by step.These copolymer materials show relatively high glass transition temperature and thermal decomposition temperature.The introduction of spiro-fluorene-9, 9'-xanthene can lower the highest occupied molecular orbital energy level of polymer DSSFX to -3.01 eV and highest occupied molecular orbital of polymer USSFX to -5.93 eV, both of which were slightly changed from those of polymer CSSFX, and the obtained polymer USSFX are expected to show improved hole injection properties.Especially, the thin solid film of polymer USSFX remains to be stable blue light emissive after being annealed at high temperatures in air for long time, and we have established an effective method to improve the spectral stabilites of polyfluorene-based blue light-emitting materials by introducing spiro-fluorene-9, 9'-xanthene into their main chains.关键词：Electroluminescent;Blue-light;Fluorene;Spiro-fluorene-9;9'-xanthene
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发布时间：2021-03-19 - 摘要：A ternary rare earth metal coordination catalyst was used for terpolymerization of carbon dioxide, propylene oxide (PO) and maleic anhydride (MA).The chemical structure as well as MA content in the terpolymer was determined by FTIR and 1H-NMR spectra.The terpolymer was denoted as PPCMA, it showed 4.1% MA content when the MA loading in the comonomer (weight ratio of MA to PO, MA/PO) was 3/97.The glass transition temperature of this PPCMA was 13.4 ℃, and the temperature at 5 wt% loss of thermal decomposition was 217 ℃, it also showed tensile strength of 2.88 MPa with elongation at break of 1669%.Therefore, this PPCMA can act as toughening material at room temperature.It was used to solve the brittleness of blend from poly(propylene carbonate) (PPC) and poly(3-hydroxylbutyrate) (PHB).When 10 wt% of PPCMA was added into blend of PPC/PHB, it showed tensile strength of 18.2 MPa, while elongation at break increased to 85%, a 4.25 times increase compared with PPC/PHB sample, therefore, PPCMA can significantly improve the brittleness of PPC/PHB blends.The polarized optical microscopy (POM) image indicated that PPC itself did not show significant influence on the crystallization of PHB, mainly due to their immiscibility.When PPCMA was added into PPC/PHB blends, the number of spherulites increased significantly, while the size of nascent spherulites of PHB became smaller, and developed much fast than that without PPCMA addition, indicating that PPCMA may be a special nuclear agent, though it was an amorphous polymer.The reason may lie in that the soft segment of PPCMA chain may enhance the hydrogen interaction between the hydroxyl group of PHB and the carbonyl group in PPC, which may be beneficial to reduce the spherulite of PHB.关键词：Carbon dioxide;Maleic anhydride;Terpolymer;Mechanical performance
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发布时间：2021-03-19 - 摘要：To develop low toxic and highly efficient gene vector, a series of random copolymers, poly(2-aminoethyl methacrylate-co-2-(diethylamino) ethyl methacrylate)s (P(AMA-co-DEAEMA)s, P), were synthesized through atom transfer radical polymerization (ATRP).Physiochemical characteristics of P/DNA complexes were analyzed by agarose gel electrophoresis, particle size measurement, and scanning electron microscopy (SEM).The results of agarose gel electrophoresis retardation assay demonstrated that random copolymer P can effectively bind DNA.The particle size of P/DNA complexes was around 400~600 nm.SEM images showed that complexes displayed a regular spherical shape.In vitro cytotoxicity measurements showed that polymer P had much lower cytotoxicity than that of 25 kDa PEI.The transfection efficiency was evaluated in HEK 293T cells, and 25 kDa PEI as well as plasmid DNA were used as positive and negative controls, respectively.The transfection efficiency of P/DNA complexes at each N/P ratio was much higher than that of plasmid DNA, and comparable to that of 25 kDa PEI/DNA complexes at N/P ratio of 10.The much reduced cytotoxicity and high transfection efficiency indicate that polymer P will find great potential as a non-viral gene vector.关键词：Gene vector;Transfection efficiency;Cytotoxicity;Atom transfer radical polymerization
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发布时间：2021-03-19 - 摘要：A redox polymer ferrocene-modified polyacrylamide (PAM-Fc) was prepared by using post-modification technology to modify polyacrylamide with grafted ferrocene functional groups in alkylation reaction in dimethyl sulfoxide directly.Chemical structure, electrochemical activity and rheological properties of PAM-Fc in aqueous solutions were investigated respectively.It was found that the thermal stability and redox property were improved significantly and the viscosity of PAM-Fc aqueous solutions increased obviously compared with pure PAM due to the hydrophobic association of Fc groups.Fc groups can stabilize the free radical of PAM polymer chains to improve the thermal stability of PAM-Fc.Furthermore, the viscosity of PAM-Fc aqueous solutions can be adjusted by adding NaCl which can shield the charge on the PAM-Fc molecule chains, -cyclodextrins being a host material which can entrap Fc groups and H2O2 which can oxidize Fc from reduction state to oxidation state and turn hydrophobic Fc to hydrophilic Fc.关键词：Polyacrylamide;Ferrocene;Rheological behavior;Redox polymer
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发布时间：2021-03-19 - 摘要：Polyethylenimine (PEI) was utilized as a carrier for mediating anti-apoptotic siRNA (siSurvivin), which could silence the expression of survivin gene.The siSurvivin was used with an antitumor drug (cisplatin) for synergistic antitumor treatment.The siRNA binding capacity of PEI was evaluated by gel retardation assay, and the complete formation of PEI/siRNA was achieved at the weight ratio of 0.4.The drug resistant ability was found to be eightfold higher in resistant cells compared with the sensitive cells, and the survivin gene was overexpressed in A549DDP cells.RT-PCR experiment proved that PEI/siSurvivin complex was capable of achieving an effective silencing effect of survivin gene, and the silencing effect did not change after the cisplatin was added.Cell apoptosis assay showed that the synergistic effect of cisplatin and gene could achieve a significant apoptosis rate of 60.9%, while cisplatin or PEI/siSurvivin complex was used alone, only about 30.2% and 19.8% of apoptosis rate could be obtained, respectively.Cell proliferation assays could further validate the effective synergistic antitumor effect of cisplatin and siSurvivin mediated by PEI.关键词：Polyethylenimine;Survivin gene;Cisplatin;Synergistic effect;Antitumor
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发布时间：2021-03-19
Research Article
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