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
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
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
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
Froth flotation is a separation process widely used in the mineral processing industry that depends on differences in particle surface properties to separate valuable materials from undesired gangue. In froth flotatio...Froth flotation is a separation process widely used in the mineral processing industry that depends on differences in particle surface properties to separate valuable materials from undesired gangue. In froth flotation, an addition of a surfactant, acting as frother is usually needed. The basic function of the frother is to produce a swarm of air bubbles, which remain sufficiently stable for the hydrophobic mineral particles to be captured by them. This Paper presents a combination method of a foaming agent-surfactant composition with desirable selectivity and foaming properties. Wherein 1-butanol (C4H10O) is a main flotation foaming agent, which decides bubble sizes in a collecting area;and tetraethylene glycol (C8H18O5) is an auxiliary foaming agent, which affects a rising velocity of the bubbles in the collecting area and a foaming capability in a selected area. Set concentrations of the two components are respectively 60 ppm for the 1-butanol and 120 ppm for the tetraethylene glycol. An addition sequence is the 1-butanol followed by the tetraethylene glycol. The dual advantages of the selectivity and foaming properties of the foaming agent-surfactant composition in the present disclosure are verified through a series of tests, and desirable yields can be obtained in practice.展开更多
Background：Improving islet graft revascularization has become a crucial task for prolonging islet graft survival.Endothelial cells （ECs） are the basis of new microvessels in an isolated islet,and EC coating has bee...Background：Improving islet graft revascularization has become a crucial task for prolonging islet graft survival.Endothelial cells （ECs） are the basis of new microvessels in an isolated islet,and EC coating has been demonstrated to improve the vascularization and survival of an islet.However,the traditional method of EC coating of islets has low efficiency in vitro.This study was conducted to evaluate the effect of a polyglycolic acid （PGA） scaffold on the efficiency of islet coating by ECs and the angiogenesis in the coated islet graft.Methods：A PGA fibrous scaffold was used for EC coating of islet culture and was evaluated for its efficiency of EC coating on islets and islet graft angiogenesis.Results：In in vitro experiments,we found that apoptosis index of ECs-coating islet in PGA group （27% ± 8%） was significantly lower than that in control group （83% ± 20%,P 〈 0.05） after 7 days culture.Stimulation index was significantly greater in the PGA group than in the control group at day 7 after ECs-coating （2.07 ± 0.31 vs.1.80 ± 0.23,P 〈 0.05）.vascular endothelial growth factor （VEGF） level in the PGA group was significantly higher than the coating in the control group after 7 days culture （52.10 ± 13.50 ng/ml vs.16.30 ± 8.10 ng/ml,P 〈 0.05）.Because of a tight,circumvallated,adhesive and three-dimensional growth microenvironment,islet cultured in a PGA scaffold had higher coating efficiency showing stronger staining intensity of enzyme than those in the control group after 14 days of culture following ECs-coating.For in vivo study,PGA scaffold significantly prolonged the average survival time of EC-coated islet graft after transplantation compared with control group （15.30 ± 5.60 days vs.8.30 ± 2.45 days,P 〈 0.05）.The angiogenesis and area of survived grafts were more in the PGA group compared with the control group by measuring the mean microvessel density （8.60 ± 1.21/mm2 vs.5.20 ± 0.87/mm2,P 〈 0.05）.In addition,expression of VEGF and tyrosin-protein kinase receptor （Tie-2） gene increased in PGA scaffold group than that in control group by real-time reverse transcription-polymerase chain reaction analysis.Conclusions：These results demonstrate that the efficiency of EC coating of islets was successfully increased by culturing ECs on a PGA scaffold.This method enhances the function,survival,and vascularization of isolated islets in vitro and in vivo.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 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.
文摘Froth flotation is a separation process widely used in the mineral processing industry that depends on differences in particle surface properties to separate valuable materials from undesired gangue. In froth flotation, an addition of a surfactant, acting as frother is usually needed. The basic function of the frother is to produce a swarm of air bubbles, which remain sufficiently stable for the hydrophobic mineral particles to be captured by them. This Paper presents a combination method of a foaming agent-surfactant composition with desirable selectivity and foaming properties. Wherein 1-butanol (C4H10O) is a main flotation foaming agent, which decides bubble sizes in a collecting area;and tetraethylene glycol (C8H18O5) is an auxiliary foaming agent, which affects a rising velocity of the bubbles in the collecting area and a foaming capability in a selected area. Set concentrations of the two components are respectively 60 ppm for the 1-butanol and 120 ppm for the tetraethylene glycol. An addition sequence is the 1-butanol followed by the tetraethylene glycol. The dual advantages of the selectivity and foaming properties of the foaming agent-surfactant composition in the present disclosure are verified through a series of tests, and desirable yields can be obtained in practice.
文摘Background：Improving islet graft revascularization has become a crucial task for prolonging islet graft survival.Endothelial cells （ECs） are the basis of new microvessels in an isolated islet,and EC coating has been demonstrated to improve the vascularization and survival of an islet.However,the traditional method of EC coating of islets has low efficiency in vitro.This study was conducted to evaluate the effect of a polyglycolic acid （PGA） scaffold on the efficiency of islet coating by ECs and the angiogenesis in the coated islet graft.Methods：A PGA fibrous scaffold was used for EC coating of islet culture and was evaluated for its efficiency of EC coating on islets and islet graft angiogenesis.Results：In in vitro experiments,we found that apoptosis index of ECs-coating islet in PGA group （27% ± 8%） was significantly lower than that in control group （83% ± 20%,P 〈 0.05） after 7 days culture.Stimulation index was significantly greater in the PGA group than in the control group at day 7 after ECs-coating （2.07 ± 0.31 vs.1.80 ± 0.23,P 〈 0.05）.vascular endothelial growth factor （VEGF） level in the PGA group was significantly higher than the coating in the control group after 7 days culture （52.10 ± 13.50 ng/ml vs.16.30 ± 8.10 ng/ml,P 〈 0.05）.Because of a tight,circumvallated,adhesive and three-dimensional growth microenvironment,islet cultured in a PGA scaffold had higher coating efficiency showing stronger staining intensity of enzyme than those in the control group after 14 days of culture following ECs-coating.For in vivo study,PGA scaffold significantly prolonged the average survival time of EC-coated islet graft after transplantation compared with control group （15.30 ± 5.60 days vs.8.30 ± 2.45 days,P 〈 0.05）.The angiogenesis and area of survived grafts were more in the PGA group compared with the control group by measuring the mean microvessel density （8.60 ± 1.21/mm2 vs.5.20 ± 0.87/mm2,P 〈 0.05）.In addition,expression of VEGF and tyrosin-protein kinase receptor （Tie-2） gene increased in PGA scaffold group than that in control group by real-time reverse transcription-polymerase chain reaction analysis.Conclusions：These results demonstrate that the efficiency of EC coating of islets was successfully increased by culturing ECs on a PGA scaffold.This method enhances the function,survival,and vascularization of isolated islets in vitro and in vivo.
