In this article different types of ultradeformable liposomes were designed and the properties of transdermal delivery were studied with sodium salicylate as model drug. These results showed that liposomes with stron...In this article different types of ultradeformable liposomes were designed and the properties of transdermal delivery were studied with sodium salicylate as model drug. These results showed that liposomes with strong hydrophilic surfactant added is a new type of penetration enhancer.展开更多
Objective To establish a body composition analysis system based on chest CT,and to observe its value for evaluating content of chest muscle and adipose.Methods T7—T8 layer CT images of 108 pneumonia patients were col...Objective To establish a body composition analysis system based on chest CT,and to observe its value for evaluating content of chest muscle and adipose.Methods T7—T8 layer CT images of 108 pneumonia patients were collected(segmented dataset),and chest CT data of 984 patients were screened from the COVID 19-CT dataset(10 cases were randomly selected as whole test dataset,the remaining 974 cases were selected as layer selection dataset).T7—T8 layer was classified based on convolutional neural network(CNN)derived networks,including ResNet,ResNeXt,MobileNet,ShuffleNet,DenseNet,EfficientNet and ConvNeXt,then the accuracy,precision,recall and specificity were used to evaluate the performance of layer selection dataset.The skeletal muscle(SM),subcutaneous adipose tissue(SAT),intermuscular adipose tissue(IMAT)and visceral adipose tissue(VAT)were segmented using classical fully CNN(FCN)derived network,including FCN,SegNet,UNet,Attention UNet,UNET++,nnUNet,UNeXt and CMUNeXt,then Dice similarity coefficient(DSC),intersection over union(IoU)and 95 Hausdorff distance(HD)were used to evaluate the performance of segmented dataset.The automatic body composition analysis system was constructed based on optimal layer selection network and segmentation network,the mean absolute error(MAE),root mean squared error(RMSE)and standard deviation(SD)of MAE were used to evaluate the performance of automatic system for testing the whole test dataset.Results The accuracy,precision,recall and specificity of DenseNet network for automatically classifying T7—T8 layer from chest CT images was 95.06%,84.83%,92.27%and 95.78%,respectively,which were all higher than those of the other layer selection networks.In segmentation of SM,SAT,IMAT and overall,DSC and IoU of UNet++network were all higher,while 95HD of UNet++network were all lower than those of the other segmentation networks.Using DenseNet as the layer selection network and UNet++as the segmentation network,MAE of the automatic body composition analysis system for predicting SM,SAT,IMAT,VAT and MAE was 27.09,6.95,6.65 and 3.35 cm 2,respectively.Conclusion The body composition analysis system based on chest CT could be used to assess content of chest muscle and adipose.Among them,the UNet++network had better segmentation performance in adipose tissue than SM.展开更多
Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN...Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN suspension was prepared by high-pressurehomogenization technique, and then mixed with carbomer gel matrix to get SLN gel. The morphology,particle size with polydispersi-ty index (PI) and zeta potential were examined by atomic forcemicroscopy (AFM) and photon correlation spectroscopy (PCS). The entrapment efficiency, stability andin vitro drug release were also studied. The transdermal drug delivery through porcine ear skin wasevaluated using modified Franz diffusion cells. Results The SLN had a spherical shape with theaverage size of (95.5 - 186.2) nm, the zeta potential of (-26.3- -15.7) mV and the entrapmentefficiency of 67.4%-90.3% for different TAA encapsulated compounds. TAA-SLN carbomer gel had goodstability, the release profile in vitro fitted Higuchi equation. In comparison with conventionalhydrogels, TAA-SLN carbomer gel resulted in higher drug permeation amount and drug deposition withinporcine ear skin after 24 h penetration experiment. Conclusion TAA-SLN carbomer gel is preparedwith stable physicochemical properties. The release profile and improved drug permeation into skinmake it be a promising vehicle for transdermal drug delivery.展开更多
Six factors and 10 levels of each factor were selected by using the (uniform design method( with the aid of the computer for preparing APS liposomes. The optimal procedure for preparing APS liposomes was established a...Six factors and 10 levels of each factor were selected by using the (uniform design method( with the aid of the computer for preparing APS liposomes. The optimal procedure for preparing APS liposomes was established and it can suit the large scale production in a pharmaceutical factory. The shelf-life of APS liposomes at 20℃ is 1.46 years. Diameters of the vesicles ( > 90% ) in APS liposomes are less than 1 μm, and the system is stable. At 40℃ the diameters of vesicles were not changed in three months. Pharmacological experiments revealed that APS liposomes exerted a strong immunoenhancement in mice. Studies in this paper established a foundation for the production and the clinical application of APS liposomes.展开更多
AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cer...AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.展开更多
To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under ...To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.展开更多
Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin w...Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.展开更多
OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided in...OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.展开更多
An anti-trichomonas vaginalis monoclonal antiboody was derivatized with palmitic acid using an activated ester of N-hydroxysuccinimide About 50% of the re-sulting antibody could be incorporated into liposomes.The lipo...An anti-trichomonas vaginalis monoclonal antiboody was derivatized with palmitic acid using an activated ester of N-hydroxysuccinimide About 50% of the re-sulting antibody could be incorporated into liposomes.The liposomes showed specific binding to T. vaginalis by IFA and cytotoxicity tests. These results clearly demonstrated the effectiveness of targeting of liposomes modified by monoclonal antibody in vitro.展开更多
The objectives of the present study were to prepare stealthy etoposide proliposomes and study the pharmacokinetics in rabbits. Blank stealthy liposomes were prepared by film dispersion method. Stealthy etoposide lipos...The objectives of the present study were to prepare stealthy etoposide proliposomes and study the pharmacokinetics in rabbits. Blank stealthy liposomes were prepared by film dispersion method. Stealthy etoposide liposomes were prepared by using the ammonium sulfate gradient loading procedure. Vacuum freeze-drying technique was used to dry stealthy etoposide liposomes. Encapsulation efficiency of stealthy etoposide proliposomes was determined by Sephadex chromatography. The morphology was observed by transmission electronic microscope. The particle size and zeta potential were measured by using electrophoretic light scattering technology. The pharmacokinetics in rabbits was evaluated by comparison with etoposide injection and conventional liposomes, respectively. Mean encapsulation efficiency of stealthy etoposide proliposomes was 83.92% ± 3.65% （n = 3）. The liposomes were round or oval. Mean particle size was （124.5 ±26.9） nm, and zeta potential was （-39.50 ±1.04） mV. Following intravenous injection administration at a dose of 1.5 mg/kg etoposide, the three kinds of etoposide preparations were fitted with the two-compartment model. T1/2 β and A UC values of stealthy etoposide proliposomes were （19.26 ± 3.16） h and （26.04 ±3.53） μg/h/mL, respectively. T1/2 β and AUC values of etoposide injection were （0.94 ± 0.21） h and （0.98 ± 0.26） μg/h/mL, respectively. T1/2β and AUC values of conventional liposomes were （7.99 ± 1.36） h and （11.65 ± 1.70） μg/h/mL, respectively. Results indicated that the stealthy etoposide proliposomes could significantly extend the duration of etoposide in blood circulation.展开更多
Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modif...Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modified drug-containing liposomes. Methods Argine-glycine-aspartic acid （RGD） tripeptide and glycine-argine-glycine-aspartic acid-serine （GRGDS） pentapeptide were used for modifications on the doxorubicin-loaded sterically stabilized liposomes （SSL-doxorubicin） for the liposome preparation, RGD-SSL-doxorubicin and GRGDS-SSL-doxorubicin, respectively. Characterizations were performed by measurements of the encapsulation efficiency, particle size and zeta potential, release rates in a simulated in vivo environment, and cytotoxicity to ovarian cancer cells. Cell uptake was investigated by flow cytometry and confocal microscopy methods. Results All encapsulation efficiencies of the liposomes were above 95%, and the modifications using RGD or GRGDS did not affect the final encapsulation efficiency. Average particle sizes of the liposomes Were in the range between 105.7 ± 3.5 nm and 130.5 ± 3.0 nm, and zeta potential values were between -3.3 ± 0.3 and -6.1 ± 0.3 mV. Approximately 2/5 of doxorubicin was released from liposomes before 12 h in the simulated in vivo environment containing fetal bovine serum. Inhibitory rates to cancer cells of the modified liposomes were slightly lower as compared to free doxorubicin. Similar phenomena were observed in the uptake measured by flow cytometry and confocal assay. After uptake applying various formulations on the cancer cells, doxorubicin was mainly distributed in the nuclei of SKOV-3 cells. Conclusion Two new doxorubicin-contained liposomes were successfully prepared and modified with argine-glycine-aspartic acid （RGD） tripeptide and glycine-argine-glycine- aspartic acid-serine （GRGDS） pentapeptide. In vitro characterization indicated that modifications did not alter significantly the properties of the sterically stabilized liposomes.展开更多
Acyl-ACP thioesterases （FATs） terminates the fatty acid synthesis and allow the transport of fatty acids out of the plastids, which are the important determinants of cellular metabolism. FATB is a member of FAT enzy...Acyl-ACP thioesterases （FATs） terminates the fatty acid synthesis and allow the transport of fatty acids out of the plastids, which are the important determinants of cellular metabolism. FATB is a member of FAT enzymes that has been described previously in most of the plants. In silico cloning is a new method that utilizes the bioinformatics on the complete genome and available EST database. In this study, a full-length cDNA clone of PtFATB gene was isolated from Populus tomentosa using this approach. It is 1,450 bp in length and the open reading frame encodes a peptide of 421 amino acids. The predicted amino acid sequence shows significant homology with those from other plant species, which contain typical domains owned by FATB proteins. The transcripts of PtFATB were abundant in leaves, and less in roots detected by using semiquantitative RT-PCR. When the shoots were subjected to the stress treatments （cold, dry, NaC1） and ABA （Abscisic acid）, the expression of PtFATB was only slightly reduced under the treatment of low temperature. This suggests that the expression of PtFATB is in a constitutive fashion. This study provides the basis not only for the identification and characterization of this gene but also for the improvement of cold tolerance by controlling the expression of the PtFATB gene in trees in near future.展开更多
文摘In this article different types of ultradeformable liposomes were designed and the properties of transdermal delivery were studied with sodium salicylate as model drug. These results showed that liposomes with strong hydrophilic surfactant added is a new type of penetration enhancer.
文摘Objective To establish a body composition analysis system based on chest CT,and to observe its value for evaluating content of chest muscle and adipose.Methods T7—T8 layer CT images of 108 pneumonia patients were collected(segmented dataset),and chest CT data of 984 patients were screened from the COVID 19-CT dataset(10 cases were randomly selected as whole test dataset,the remaining 974 cases were selected as layer selection dataset).T7—T8 layer was classified based on convolutional neural network(CNN)derived networks,including ResNet,ResNeXt,MobileNet,ShuffleNet,DenseNet,EfficientNet and ConvNeXt,then the accuracy,precision,recall and specificity were used to evaluate the performance of layer selection dataset.The skeletal muscle(SM),subcutaneous adipose tissue(SAT),intermuscular adipose tissue(IMAT)and visceral adipose tissue(VAT)were segmented using classical fully CNN(FCN)derived network,including FCN,SegNet,UNet,Attention UNet,UNET++,nnUNet,UNeXt and CMUNeXt,then Dice similarity coefficient(DSC),intersection over union(IoU)and 95 Hausdorff distance(HD)were used to evaluate the performance of segmented dataset.The automatic body composition analysis system was constructed based on optimal layer selection network and segmentation network,the mean absolute error(MAE),root mean squared error(RMSE)and standard deviation(SD)of MAE were used to evaluate the performance of automatic system for testing the whole test dataset.Results The accuracy,precision,recall and specificity of DenseNet network for automatically classifying T7—T8 layer from chest CT images was 95.06%,84.83%,92.27%and 95.78%,respectively,which were all higher than those of the other layer selection networks.In segmentation of SM,SAT,IMAT and overall,DSC and IoU of UNet++network were all higher,while 95HD of UNet++network were all lower than those of the other segmentation networks.Using DenseNet as the layer selection network and UNet++as the segmentation network,MAE of the automatic body composition analysis system for predicting SM,SAT,IMAT,VAT and MAE was 27.09,6.95,6.65 and 3.35 cm 2,respectively.Conclusion The body composition analysis system based on chest CT could be used to assess content of chest muscle and adipose.Among them,the UNet++network had better segmentation performance in adipose tissue than SM.
文摘Aim To prepare triamcinolone-acetonide-acetate (TAA)-loaded solid lipidnanoparticles (SLN) carbomer gel with tripalmitin glyceride (TPG), and investigate theircharacteristics and transdermal drug delivery. Methods SLN suspension was prepared by high-pressurehomogenization technique, and then mixed with carbomer gel matrix to get SLN gel. The morphology,particle size with polydispersi-ty index (PI) and zeta potential were examined by atomic forcemicroscopy (AFM) and photon correlation spectroscopy (PCS). The entrapment efficiency, stability andin vitro drug release were also studied. The transdermal drug delivery through porcine ear skin wasevaluated using modified Franz diffusion cells. Results The SLN had a spherical shape with theaverage size of (95.5 - 186.2) nm, the zeta potential of (-26.3- -15.7) mV and the entrapmentefficiency of 67.4%-90.3% for different TAA encapsulated compounds. TAA-SLN carbomer gel had goodstability, the release profile in vitro fitted Higuchi equation. In comparison with conventionalhydrogels, TAA-SLN carbomer gel resulted in higher drug permeation amount and drug deposition withinporcine ear skin after 24 h penetration experiment. Conclusion TAA-SLN carbomer gel is preparedwith stable physicochemical properties. The release profile and improved drug permeation into skinmake it be a promising vehicle for transdermal drug delivery.
文摘Six factors and 10 levels of each factor were selected by using the (uniform design method( with the aid of the computer for preparing APS liposomes. The optimal procedure for preparing APS liposomes was established and it can suit the large scale production in a pharmaceutical factory. The shelf-life of APS liposomes at 20℃ is 1.46 years. Diameters of the vesicles ( > 90% ) in APS liposomes are less than 1 μm, and the system is stable. At 40℃ the diameters of vesicles were not changed in three months. Pharmacological experiments revealed that APS liposomes exerted a strong immunoenhancement in mice. Studies in this paper established a foundation for the production and the clinical application of APS liposomes.
文摘AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.
文摘To explore the differences of sensitivities to chilling and strong light in indica and japonica rice (Oryza sativa L), the changes in unsaturation of thylakoid membrane lipids and xanthophyll cycle were studied under chilling condition and strong light. The contents of unsaturated fatty acids of thylakoid membrane lipids decreased and that of the saturated ones increased with the time of chilling and strong light treatment, resulting in the reduction of the index of unsaturation of fatty acids (IUFA). The activity of violaxanthin deepoxidase (VDE), a key enzyme of xanthophyll cycle, also reduced. The content of violaxanthin (V) increased, and the contents of antheraxanthin (A) and zeaxanthin M decreased, the ratio of (A+Z)/ (A+Z+V) decreased correspondingly. Arrhenius analysis showed that VDE was sensitive to both chilling and unsaturation level of thylakoid membrane lipids. Correlation analysis showed that there was distinctly positive relationships between IUFA of thylakoid membrane lipids and the activity of VDE, Fv/Fm, and D, protein content. Lower IUFA values, less fluidity and stability of thylakoid membrane lipids, lower VDE activity and (A+Z)/(A+Z+V) ratio were found in indica rice cv. Shanyou 63 than in japonica rice cv. 9516 under chilling and strong light.
文摘Aim To evaluate liposome as an injectable delivery system of proteins, insulin was chosen as model drug and the hypoglycemic effect of PEG-coated liposomal insulin was tested.Methods The PEG-coated liposomal insulin was prepared by reversal-phase emulsion evaporation.For pharmacodynamic study, insulin (2.5 IU*kg-1) was intravenously administered in phosphated-buffered saline (PBS) solution, conventional liposomes, and PEG-coated liposomes, separately, to normal Wistar rats.Blood glucose levels were determined by the glucose oxidase method.Results The mean diameter of the PEG-coated liposomal insulin was 58.4 nm, while the encapsulation ratio reached 18.33%.After intravenous administration of insulin solution, insulin liposome, and PEG-coated liposomal insulin, the minimum blood glucose concentrations (Cmin %) reached 25.26±5.75%, 33.92±12.42%, and 42.39±10.5% of the initial level, respectively, and the time periods to reach the minimum blood glucose level (Tmin) were 0.7±0.3 h, 1.2±0.4 h, and 2.3±0.7 h, respectively.The relative pharmacological bioavailabilities of insulin liposome and PEG-coated liposomal insulin were 98.03% and 99.70%, respectively, compared with the control of insulin solution.Conclusion PEG-coated liposome can be developed as a relatively sustained injectable delivery system for insulin.Moreover, the liposome coated with PEG may have advantages over normal liposome.
文摘OBJECTIVE To examine the possibility of human sodium iodide symporter （hNIS） protein expression in lung cancer cells. METHODS Human lung A549 cancer cells were thawed and cultured in vitro. The cells were divided into an experimental group transfected with a recombinant pcDNA3-hNIS plasmid and a control group transfected only with a pcDNA3 plasmid. The recombinant plasmid vector encoding the hNIS gene （pcDNA3-hNIS） was amplified, purified and identified. The hNIS gene was followed by DNA sequencing. A Western blot and an immunohistochemical assay were applied to detect the hNIS protein expression in the transfected human lung A549 cancer cells. RESULTS Restriction enzyme digestion and DNA sequencing results showed the size and direction of the inserted gene in the recombinant pcD- NA3-hNIS plasmid was correct. The Western blot method and immunohistochemical analysis showed a positive NIS protein expression in the experimental group. The NIS protein was detected mainly in the cell membranes showing a positive rate up to 70.6% with no expression of the NIS protein in the control group. There was a significant difference between two groups （P=0.000）. CONCLUSION The hNIS gene was transfected effectively into human lung A549 cancer cells mediated by Lipofectamine 2000, and was expressed with its protein in vitro.
文摘An anti-trichomonas vaginalis monoclonal antiboody was derivatized with palmitic acid using an activated ester of N-hydroxysuccinimide About 50% of the re-sulting antibody could be incorporated into liposomes.The liposomes showed specific binding to T. vaginalis by IFA and cytotoxicity tests. These results clearly demonstrated the effectiveness of targeting of liposomes modified by monoclonal antibody in vitro.
基金Research Projects of Heilongjiang Science and Technology Department (Grant No.GC05C31601).
文摘The objectives of the present study were to prepare stealthy etoposide proliposomes and study the pharmacokinetics in rabbits. Blank stealthy liposomes were prepared by film dispersion method. Stealthy etoposide liposomes were prepared by using the ammonium sulfate gradient loading procedure. Vacuum freeze-drying technique was used to dry stealthy etoposide liposomes. Encapsulation efficiency of stealthy etoposide proliposomes was determined by Sephadex chromatography. The morphology was observed by transmission electronic microscope. The particle size and zeta potential were measured by using electrophoretic light scattering technology. The pharmacokinetics in rabbits was evaluated by comparison with etoposide injection and conventional liposomes, respectively. Mean encapsulation efficiency of stealthy etoposide proliposomes was 83.92% ± 3.65% （n = 3）. The liposomes were round or oval. Mean particle size was （124.5 ±26.9） nm, and zeta potential was （-39.50 ±1.04） mV. Following intravenous injection administration at a dose of 1.5 mg/kg etoposide, the three kinds of etoposide preparations were fitted with the two-compartment model. T1/2 β and A UC values of stealthy etoposide proliposomes were （19.26 ± 3.16） h and （26.04 ±3.53） μg/h/mL, respectively. T1/2 β and AUC values of etoposide injection were （0.94 ± 0.21） h and （0.98 ± 0.26） μg/h/mL, respectively. T1/2β and AUC values of conventional liposomes were （7.99 ± 1.36） h and （11.65 ± 1.70） μg/h/mL, respectively. Results indicated that the stealthy etoposide proliposomes could significantly extend the duration of etoposide in blood circulation.
基金National Natural Science Foundation of China(Grant No. 30572261)the 985 Projects (Phase II) of theState Key Laboratory of Natural and Biomimetic Drugs(Peking University, China).
文摘Aim Peptides as ligands have shown the active targeting properties to the receptors like integrins, a family of receptors over-expressed in cancers. The present study was to develop and characterize two peptides modified drug-containing liposomes. Methods Argine-glycine-aspartic acid （RGD） tripeptide and glycine-argine-glycine-aspartic acid-serine （GRGDS） pentapeptide were used for modifications on the doxorubicin-loaded sterically stabilized liposomes （SSL-doxorubicin） for the liposome preparation, RGD-SSL-doxorubicin and GRGDS-SSL-doxorubicin, respectively. Characterizations were performed by measurements of the encapsulation efficiency, particle size and zeta potential, release rates in a simulated in vivo environment, and cytotoxicity to ovarian cancer cells. Cell uptake was investigated by flow cytometry and confocal microscopy methods. Results All encapsulation efficiencies of the liposomes were above 95%, and the modifications using RGD or GRGDS did not affect the final encapsulation efficiency. Average particle sizes of the liposomes Were in the range between 105.7 ± 3.5 nm and 130.5 ± 3.0 nm, and zeta potential values were between -3.3 ± 0.3 and -6.1 ± 0.3 mV. Approximately 2/5 of doxorubicin was released from liposomes before 12 h in the simulated in vivo environment containing fetal bovine serum. Inhibitory rates to cancer cells of the modified liposomes were slightly lower as compared to free doxorubicin. Similar phenomena were observed in the uptake measured by flow cytometry and confocal assay. After uptake applying various formulations on the cancer cells, doxorubicin was mainly distributed in the nuclei of SKOV-3 cells. Conclusion Two new doxorubicin-contained liposomes were successfully prepared and modified with argine-glycine-aspartic acid （RGD） tripeptide and glycine-argine-glycine- aspartic acid-serine （GRGDS） pentapeptide. In vitro characterization indicated that modifications did not alter significantly the properties of the sterically stabilized liposomes.
基金This work was supported by project "Regulation of Composition and Saturation of Fatty Acid in Trees by Genetic Engineering", Introduction of Foreign Advanced Agricultural Science and Technology into China (No. 2005-4-52).
文摘Acyl-ACP thioesterases （FATs） terminates the fatty acid synthesis and allow the transport of fatty acids out of the plastids, which are the important determinants of cellular metabolism. FATB is a member of FAT enzymes that has been described previously in most of the plants. In silico cloning is a new method that utilizes the bioinformatics on the complete genome and available EST database. In this study, a full-length cDNA clone of PtFATB gene was isolated from Populus tomentosa using this approach. It is 1,450 bp in length and the open reading frame encodes a peptide of 421 amino acids. The predicted amino acid sequence shows significant homology with those from other plant species, which contain typical domains owned by FATB proteins. The transcripts of PtFATB were abundant in leaves, and less in roots detected by using semiquantitative RT-PCR. When the shoots were subjected to the stress treatments （cold, dry, NaC1） and ABA （Abscisic acid）, the expression of PtFATB was only slightly reduced under the treatment of low temperature. This suggests that the expression of PtFATB is in a constitutive fashion. This study provides the basis not only for the identification and characterization of this gene but also for the improvement of cold tolerance by controlling the expression of the PtFATB gene in trees in near future.
