Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer-related mortality worldwide.Endoscopic submucosal dissection(ESD)is widely used for the resection of early esophageal c...Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer-related mortality worldwide.Endoscopic submucosal dissection(ESD)is widely used for the resection of early esophageal cancer.However,post-ESD esophageal stricture is a common long-term complication,which requires attention.Patients with post-ESD esophageal stricture often experience dysphagia and require multiple dilatations,which greatly affects their quality of life and increases healthcare costs.Therefore,to manage post-ESD esophageal stricture,researchers are actively exploring various strategies,such as pharmaceutical interventions,endoscopic balloon dilation,and esophageal stenting.Although steroids-based therapy has achieved some success,steroids can lead to complications such as osteoporosis and infection.Meanwhile,endoscopic balloon dilatation is effective in the short term,but is prone to recurrence and perforation.Additionally,esophageal stenting can alleviate the stricture,but is associated with discomfort during stenting and the complication of easy displacement also present challenges.Tissue engineering has evolved rapidly in recent years,and hydrogel materials have good biodegradability and biocompatibility.A novel type of polyglycolic acid(PGA)sheets has been found to be effective in preventing esophageal stricture after ESD,with the advantages of a simple operation and low complication rate.PGA membranes act as a biophysical barrier to cover the wound as well as facilitate the delivery of medications to promote wound repair and healing.However,there is still a lack of multicenter,large-sample randomized controlled clinical studies focused on the treatment of post-ESD esophageal strictures with PGA membrane,which will be a promising direction for future advancements in this field.展开更多
For improving its hydrophilicity and biocompatibility,and preserving filament mechanical properties at the same time,polyglycolic acid( PGA) filament was modified by potassium dichromate solution with different proces...For improving its hydrophilicity and biocompatibility,and preserving filament mechanical properties at the same time,polyglycolic acid( PGA) filament was modified by potassium dichromate solution with different processing time. Breaking force and water contact angle were tested. Surface changes before and after surface modifications were tested with scanning electron microscopy(SEM). Furthermore,differential scanning calorimeter(DSC) and Fourier transform infrared spectrometry(FTIR) were used to analyze the changes of molecular structure and functional group. Experimental results showed that 6 min was the most suitable time for improving hydrophilicity of PGA filament and preserving its mechanical properties.展开更多
In order to effectively control the drug-release rate of medical textiles,biodegradable polycaprolactone(PCL) and polyglycolic acid(PGA) were blended at various mass ratios to prepare composite masterbatches for medic...In order to effectively control the drug-release rate of medical textiles,biodegradable polycaprolactone(PCL) and polyglycolic acid(PGA) were blended at various mass ratios to prepare composite masterbatches for medical textiles.The surface morphology and the chemical structure of the masterbatches were analyzed.The crystallization,mass losses,strengths and drug-release rates of the composite masterbatches at different PCL/PGA mass ratios were explored.The results show that the degradation rate of the PGA carrier is obvious higher than that of the PCL carrier,and PCL,PGA and the tea polyphenol(TP) drug just physically mix without chemical reaction.During the degradation,the strength of the composite masterbatches gradually decreases.In addition,the drug-release rates of composite masterbatches at different mass ratios are different,and the more the PGA in the composite masterbatches,the faster the drug release of the composite masterbatches.The drug-release rate of the composite masterbatches can be controlled by adjusting the contents of PCL and PGA.展开更多
AIM To assess the effect of polyglycolic acid(PGA) plus stent placement compared with stent placement alone in the prevention of post-endoscopic submucosal dissection(ESD) esophageal stricture in early-stage esophagea...AIM To assess the effect of polyglycolic acid(PGA) plus stent placement compared with stent placement alone in the prevention of post-endoscopic submucosal dissection(ESD) esophageal stricture in early-stage esophageal cancer(EC) patients. METHODS Seventy EC patients undergoing ESD were enrolled in this randomized, controlled study. Patients were allocated randomly at a 1:1 ratio into two groups as follows:(1) PGA plus stent group(PGA sheet-coated stent placement was performed); and(2) Stent group(only stent placement was performed). This study was registered on http://www.chictr.org.cn(No. chictrinr-16008709). RESULTS The occurrence rate of esophageal stricture in the PGA plus stent group was 20.5%(n = 7), which was lower than that in the stent group(46.9%, n = 15)(P = 0.024). The mean value of esophageal stricture time was 59.6 ± 16.1 d and 70.7 ± 28.6 d in the PGA plus stent group and stent group(P = 0.174), respectively. Times of balloon dilatation in the PGA plus stent group were less than those in the stent group [4(2-5) vs 6(1-14), P = 0.007]. The length(P = 0.080) and diameter(P = 0.061) of esophageal strictures were numerically decreased in the PGA plus stent group, whereas no difference in location(P = 0.232) between the two groups was found. Multivariate logistic analysis suggested that PGA plus stent placement(P = 0.026) was an independent predictive factor for a lower risk of esophageal stricture, while location in the middle third(P = 0.034) and circumferential range = 1/1(P = 0.028) could independently predict a higher risk of esophageal stricture in EC patients after ESD. CONCLUSION PGA plus stent placement is more effective in preventing post-ESD esophageal stricture compared with stent placement alone in EC patients with earlystage disease.展开更多
AIM To evaluate appropriate and rapid polyglycolic acid sheet(PGAs) covering time using device delivery station system(DDSS).METHODS This pilot basic study was conducted to evaluate the potential of accurate and rapid...AIM To evaluate appropriate and rapid polyglycolic acid sheet(PGAs) covering time using device delivery station system(DDSS).METHODS This pilot basic study was conducted to evaluate the potential of accurate and rapid PGAs delivery using DDSS. Three 11-month-old female Beagle dogs were used in this study. Two endoscopic submucosal dissections(ESDs) 4 cm in diameter were performed in lesser curvature of middle gastric body and greater curvature of antrum(total 6 ESDs performed). DDSS(3 cm length, 12 mm in outer diameter) has 2 chambers which 16 cm^2 large 2 PGAs were stored, and DDSS was attached post ESD ulcers, respectively. Beriplast P?(CSL Behring K.K., Tokyo, Japan)(combination of fibringlue and thrombin) was applied equally to the artificial ulcer, and tight attachment of 2 PGAs with DDSS were completed. The evaluation items were covering times, post ESD bleeding and perforation during ESD.RESULTS The covering time of PGAs(defined as the duration from the beginning of endoscope insertion into the mouth to the end of the fibrin glue coating process) was 6.07(4.86-8.29) min. There was no postESD bleeding(1-7 d after ESD), and there was no perforation during ESD.CONCLUSION DDSS was very useful for rapid delivering and tight attachment of PGAs, and has potentials of multipurpose delivery station system.展开更多
Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strengt...Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strength as the same time. PGA fibers are dipped in H_2O_2 solution a certain time for modification. Scanning electron microscopy( SEM) was used to observe the surface morphology of PGA fibers before and after modification. The varying of PGA macromolecule was examined with Fourier transform infrared spectroscopy( FTIR) analyses. X-ray diffraction( XRD) and differential scanning calorimetry( DSC) analysis showed that crystallinity slightly decreases. Mechanical performance test showed tensile force of modified PGA fiber was increased. The water contact angle test indicated the improving of hydrophilic. A cell proliferation assay showed that fibroblast cells attach and proliferate well on the fibers, which meant the modified fibers possess good cytocompatibility. These results suggest that H_2O_2 surface modification is easy to operate and a advantageous modification method for PGA fibers.展开更多
Acupoint catgut embedding therapy(ACET),filling the gaps of traditional Chinese medicine acupuncture treatment,has been widely used for the treatment of many diseases with significant effects.The aim of this paper is ...Acupoint catgut embedding therapy(ACET),filling the gaps of traditional Chinese medicine acupuncture treatment,has been widely used for the treatment of many diseases with significant effects.The aim of this paper is to obtain polyglycollide acid(PGA)fibers with higher performance at a lower cost,and ensure that PGA can meet the clinical requirements as well.PGA fibers with different diameters were spun as embedding materials.The mechanical performance,thermodynamic and biodegradable properties of PGA fibers were studied under different spinning process parameters,including spinning speed,drawing temperature and stretching ratio.The experimental results showed that the optimum spinning parameters were the spinning speed at 150 m/min,the drawing temperature of 45 ℃,and the stretching ratio of 4.0.The initial modulus of PGA fibers was 3.876 N/tex.The crystallization degree was 68% and the degradation performance was in consistent with treatment cycle of patients.展开更多
Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurem...Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurements are required. Electron Spin Resonance (ESR) is a well-established Reference Standard Dosimetry system in industrial applications of ionising radiation, and its use is also proposed in radiation therapy and accident dosimetry. In the present experimental work, PGA solid state dosimeter (SSD) has been investigated using ESR spectroscopy to study the gamma radiation response of this material and to evaluate its dosimetric characteristics: dose response, room temperature fading, heat treatment effect during post-irradiation storage. Results obtained up to now confirm that PGA seems to be suitable material for ESR dosimetry applications.展开更多
Pseudo glycolythiourea acid（PGA） was synthesized and used as depressant for flotation separation of Cu and Mo.The results indicate that a low amount of PGA has strong depression effect on chalcopyrite.Mo grade of 26...Pseudo glycolythiourea acid（PGA） was synthesized and used as depressant for flotation separation of Cu and Mo.The results indicate that a low amount of PGA has strong depression effect on chalcopyrite.Mo grade of 26.17% and recovery of 89.83% were achieved with rougher and scavenger one time and cleaners twice,while the recovery of Mo was deceased by 2% when Na2S was used as depressant.Measurement on adsorption of PGA on the mineral surface indicates that PGA and xanthate were adsorbed on mineral surface by competition,and PGA was adsorbed on chalcopyrite surface much stronger than on molybdenite surface.FTIR results indicate a chemical absorption process for PGA on chalcopyrite surface and a physical adsorption process on molybdenite surface.The frontier orbital calculation shows that the S atom is an active center,and the depression of PGA can be explained with the Fermi level of energy based on the electrochemical mechanism.展开更多
目的可吸收生物材料聚羟乙酸(PGA)与成纤维细胞已被证实可以应用于体外组织工程肌腱的构建,本试验旨在探讨应用人皮肤成纤维细胞与PGA在体外进行组织构建时的适宜接种浓度。方法酶消化法获得人皮肤成纤维细胞经体外培养、扩增至第2代,...目的可吸收生物材料聚羟乙酸(PGA)与成纤维细胞已被证实可以应用于体外组织工程肌腱的构建,本试验旨在探讨应用人皮肤成纤维细胞与PGA在体外进行组织构建时的适宜接种浓度。方法酶消化法获得人皮肤成纤维细胞经体外培养、扩增至第2代,按照低、中、高三种浓度接种于PGA材料分别作为实验组1、2、3,传统浓度细胞接种的作为对照组,各组样本数n均为3,分别于接种后3天、1周、2周和4周进行观察和检测。结果接种后3天实验各组无明显差异,细胞在材料上黏附伸展良好。1周和2周时,各组细胞均有明显增殖,并分泌细胞外基质(ECM extra cellular matrix),但实验组1、2的ECM不如实验组3和对照组丰富,此后该现象更为明显。至第4周时,实验组1仅形成厚薄不均的薄膜状物,其余三组均形成组织样结构,但实验组2形成的细胞--材料复合物结构略为松散。结论应用本实验组中高浓度接种皮肤成纤维细胞在体外构建工程化组织可以达到传统所用更高浓度的接种效果,以节约细胞,减少取材。展开更多
文摘Esophageal cancer is the seventh most common type of cancer and the sixth leading cause of cancer-related mortality worldwide.Endoscopic submucosal dissection(ESD)is widely used for the resection of early esophageal cancer.However,post-ESD esophageal stricture is a common long-term complication,which requires attention.Patients with post-ESD esophageal stricture often experience dysphagia and require multiple dilatations,which greatly affects their quality of life and increases healthcare costs.Therefore,to manage post-ESD esophageal stricture,researchers are actively exploring various strategies,such as pharmaceutical interventions,endoscopic balloon dilation,and esophageal stenting.Although steroids-based therapy has achieved some success,steroids can lead to complications such as osteoporosis and infection.Meanwhile,endoscopic balloon dilatation is effective in the short term,but is prone to recurrence and perforation.Additionally,esophageal stenting can alleviate the stricture,but is associated with discomfort during stenting and the complication of easy displacement also present challenges.Tissue engineering has evolved rapidly in recent years,and hydrogel materials have good biodegradability and biocompatibility.A novel type of polyglycolic acid(PGA)sheets has been found to be effective in preventing esophageal stricture after ESD,with the advantages of a simple operation and low complication rate.PGA membranes act as a biophysical barrier to cover the wound as well as facilitate the delivery of medications to promote wound repair and healing.However,there is still a lack of multicenter,large-sample randomized controlled clinical studies focused on the treatment of post-ESD esophageal strictures with PGA membrane,which will be a promising direction for future advancements in this field.
基金Shanghai Municipality Science and Technology Commission,China(No.12DZ1940300)
文摘For improving its hydrophilicity and biocompatibility,and preserving filament mechanical properties at the same time,polyglycolic acid( PGA) filament was modified by potassium dichromate solution with different processing time. Breaking force and water contact angle were tested. Surface changes before and after surface modifications were tested with scanning electron microscopy(SEM). Furthermore,differential scanning calorimeter(DSC) and Fourier transform infrared spectrometry(FTIR) were used to analyze the changes of molecular structure and functional group. Experimental results showed that 6 min was the most suitable time for improving hydrophilicity of PGA filament and preserving its mechanical properties.
基金Transformation and Guidance of Scientific and Technological Achievements in Shanxi Province,China(No.202104021301053)Fundamental Research Program of Shanxi Province,China(Nos. 20210302123114 and 202203021211146)+1 种基金Transformation of Scientific and Technological Achievements Programs of Higher Education Institutions in Shanxi Province,China(TSTAP)(No. 2020CG014)Open Project Program of Key Lab for Sport Shoes Upper Materials of Fujian Province,Fujian Huafeng New Material Co.,Ltd.,China(No.S SUM213)。
文摘In order to effectively control the drug-release rate of medical textiles,biodegradable polycaprolactone(PCL) and polyglycolic acid(PGA) were blended at various mass ratios to prepare composite masterbatches for medical textiles.The surface morphology and the chemical structure of the masterbatches were analyzed.The crystallization,mass losses,strengths and drug-release rates of the composite masterbatches at different PCL/PGA mass ratios were explored.The results show that the degradation rate of the PGA carrier is obvious higher than that of the PCL carrier,and PCL,PGA and the tea polyphenol(TP) drug just physically mix without chemical reaction.During the degradation,the strength of the composite masterbatches gradually decreases.In addition,the drug-release rates of composite masterbatches at different mass ratios are different,and the more the PGA in the composite masterbatches,the faster the drug release of the composite masterbatches.The drug-release rate of the composite masterbatches can be controlled by adjusting the contents of PCL and PGA.
文摘AIM To assess the effect of polyglycolic acid(PGA) plus stent placement compared with stent placement alone in the prevention of post-endoscopic submucosal dissection(ESD) esophageal stricture in early-stage esophageal cancer(EC) patients. METHODS Seventy EC patients undergoing ESD were enrolled in this randomized, controlled study. Patients were allocated randomly at a 1:1 ratio into two groups as follows:(1) PGA plus stent group(PGA sheet-coated stent placement was performed); and(2) Stent group(only stent placement was performed). This study was registered on http://www.chictr.org.cn(No. chictrinr-16008709). RESULTS The occurrence rate of esophageal stricture in the PGA plus stent group was 20.5%(n = 7), which was lower than that in the stent group(46.9%, n = 15)(P = 0.024). The mean value of esophageal stricture time was 59.6 ± 16.1 d and 70.7 ± 28.6 d in the PGA plus stent group and stent group(P = 0.174), respectively. Times of balloon dilatation in the PGA plus stent group were less than those in the stent group [4(2-5) vs 6(1-14), P = 0.007]. The length(P = 0.080) and diameter(P = 0.061) of esophageal strictures were numerically decreased in the PGA plus stent group, whereas no difference in location(P = 0.232) between the two groups was found. Multivariate logistic analysis suggested that PGA plus stent placement(P = 0.026) was an independent predictive factor for a lower risk of esophageal stricture, while location in the middle third(P = 0.034) and circumferential range = 1/1(P = 0.028) could independently predict a higher risk of esophageal stricture in EC patients after ESD. CONCLUSION PGA plus stent placement is more effective in preventing post-ESD esophageal stricture compared with stent placement alone in EC patients with earlystage disease.
基金Supported by The Translational Research Programthe Strategic Promotion for Practical Applications of Innovative Medical Technology(TR-SPRINT)from the Japan Agency for Medical Research and Development(AMED)
文摘AIM To evaluate appropriate and rapid polyglycolic acid sheet(PGAs) covering time using device delivery station system(DDSS).METHODS This pilot basic study was conducted to evaluate the potential of accurate and rapid PGAs delivery using DDSS. Three 11-month-old female Beagle dogs were used in this study. Two endoscopic submucosal dissections(ESDs) 4 cm in diameter were performed in lesser curvature of middle gastric body and greater curvature of antrum(total 6 ESDs performed). DDSS(3 cm length, 12 mm in outer diameter) has 2 chambers which 16 cm^2 large 2 PGAs were stored, and DDSS was attached post ESD ulcers, respectively. Beriplast P?(CSL Behring K.K., Tokyo, Japan)(combination of fibringlue and thrombin) was applied equally to the artificial ulcer, and tight attachment of 2 PGAs with DDSS were completed. The evaluation items were covering times, post ESD bleeding and perforation during ESD.RESULTS The covering time of PGAs(defined as the duration from the beginning of endoscope insertion into the mouth to the end of the fibrin glue coating process) was 6.07(4.86-8.29) min. There was no postESD bleeding(1-7 d after ESD), and there was no perforation during ESD.CONCLUSION DDSS was very useful for rapid delivering and tight attachment of PGAs, and has potentials of multipurpose delivery station system.
基金Shanghai Science and Technical Committee,China(No.10411953300)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LZ0902)Minhang District Industry-Study-Research Cooperation,China(No.2012MH202)
文摘Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strength as the same time. PGA fibers are dipped in H_2O_2 solution a certain time for modification. Scanning electron microscopy( SEM) was used to observe the surface morphology of PGA fibers before and after modification. The varying of PGA macromolecule was examined with Fourier transform infrared spectroscopy( FTIR) analyses. X-ray diffraction( XRD) and differential scanning calorimetry( DSC) analysis showed that crystallinity slightly decreases. Mechanical performance test showed tensile force of modified PGA fiber was increased. The water contact angle test indicated the improving of hydrophilic. A cell proliferation assay showed that fibroblast cells attach and proliferate well on the fibers, which meant the modified fibers possess good cytocompatibility. These results suggest that H_2O_2 surface modification is easy to operate and a advantageous modification method for PGA fibers.
基金“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘Acupoint catgut embedding therapy(ACET),filling the gaps of traditional Chinese medicine acupuncture treatment,has been widely used for the treatment of many diseases with significant effects.The aim of this paper is to obtain polyglycollide acid(PGA)fibers with higher performance at a lower cost,and ensure that PGA can meet the clinical requirements as well.PGA fibers with different diameters were spun as embedding materials.The mechanical performance,thermodynamic and biodegradable properties of PGA fibers were studied under different spinning process parameters,including spinning speed,drawing temperature and stretching ratio.The experimental results showed that the optimum spinning parameters were the spinning speed at 150 m/min,the drawing temperature of 45 ℃,and the stretching ratio of 4.0.The initial modulus of PGA fibers was 3.876 N/tex.The crystallization degree was 68% and the degradation performance was in consistent with treatment cycle of patients.
文摘Reference Standard Dosimeters are used to calibrate radiation environments and routine dosimeters. It can also be used in routine dosimetry applications for radiation processing where higher quality dosimetry measurements are required. Electron Spin Resonance (ESR) is a well-established Reference Standard Dosimetry system in industrial applications of ionising radiation, and its use is also proposed in radiation therapy and accident dosimetry. In the present experimental work, PGA solid state dosimeter (SSD) has been investigated using ESR spectroscopy to study the gamma radiation response of this material and to evaluate its dosimetric characteristics: dose response, room temperature fading, heat treatment effect during post-irradiation storage. Results obtained up to now confirm that PGA seems to be suitable material for ESR dosimetry applications.
基金Project(51164001) supported by the National Natural Science Foundation of ChinaProject(0991082) supported by the Science and Technology Department of Guangxi,ChinaProject(GJR201147-12) supported by Guangxi Higher Education Institutes Talent Highland Innovation Team Scheme,China
文摘Pseudo glycolythiourea acid（PGA） was synthesized and used as depressant for flotation separation of Cu and Mo.The results indicate that a low amount of PGA has strong depression effect on chalcopyrite.Mo grade of 26.17% and recovery of 89.83% were achieved with rougher and scavenger one time and cleaners twice,while the recovery of Mo was deceased by 2% when Na2S was used as depressant.Measurement on adsorption of PGA on the mineral surface indicates that PGA and xanthate were adsorbed on mineral surface by competition,and PGA was adsorbed on chalcopyrite surface much stronger than on molybdenite surface.FTIR results indicate a chemical absorption process for PGA on chalcopyrite surface and a physical adsorption process on molybdenite surface.The frontier orbital calculation shows that the S atom is an active center,and the depression of PGA can be explained with the Fermi level of energy based on the electrochemical mechanism.
文摘目的可吸收生物材料聚羟乙酸(PGA)与成纤维细胞已被证实可以应用于体外组织工程肌腱的构建,本试验旨在探讨应用人皮肤成纤维细胞与PGA在体外进行组织构建时的适宜接种浓度。方法酶消化法获得人皮肤成纤维细胞经体外培养、扩增至第2代,按照低、中、高三种浓度接种于PGA材料分别作为实验组1、2、3,传统浓度细胞接种的作为对照组,各组样本数n均为3,分别于接种后3天、1周、2周和4周进行观察和检测。结果接种后3天实验各组无明显差异,细胞在材料上黏附伸展良好。1周和2周时,各组细胞均有明显增殖,并分泌细胞外基质(ECM extra cellular matrix),但实验组1、2的ECM不如实验组3和对照组丰富,此后该现象更为明显。至第4周时,实验组1仅形成厚薄不均的薄膜状物,其余三组均形成组织样结构,但实验组2形成的细胞--材料复合物结构略为松散。结论应用本实验组中高浓度接种皮肤成纤维细胞在体外构建工程化组织可以达到传统所用更高浓度的接种效果,以节约细胞,减少取材。
