Background Several clinical trials have shown that rapamycin-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The Firebird stent and the Excel stent （coated...Background Several clinical trials have shown that rapamycin-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The Firebird stent and the Excel stent （coated with bioabsorbable polymer） are two different types of rapamycin-eluUng stents made in China, both have been recently approved for clinical use in China by State Food and Drug Administration. However, it is unclear whether there are differences in safety and efficacy between the two types of stents in daily practice. Methods In the month of June 2006, a total of 190 consecutive patients were treated exclusively with Firebird stents （n=93, Firebird group） or Excel stents （n=97, Excel group） in our center and were included in this study. The frequency of major adverse cardiac events （MACE, a composite of death, myocardial infarction or target lesion revascularization）, binary restenosis, and late lumen loss and stent thrombosis dudng a six-month follow-up period were compared between the two groups. Results Patient and lesion characteristics were comparable between the groups. Major adverse cardiac event rates were low in hospital and at 6 months （2.1% in the Excel group and 0% in the Firebird group, P〉 0.05）. The 6-month angiographic in-stent restenosis rate was 0% in both groups, with an associated late loss of （0.15 ± 0.21） mm versus （0.14 ± 0.20） mm （P=0.858） and the in-segment restenosis rate was also 0% for the Excel group and the Firebird group. There was no definite stent thrombosis identified in either group during the six-month follow-up period and only one patient in the Excel group had probable stent thrombosis in hospital. Conclusions Results from this mid-term, single-center study showed that both of the Firebird and the Excel rapamycin eluUng stent had similar effects on reducing the incidence of MACE and the risk of restenosis （both in-stent and in-segment binary restenosis） after PCI in daily practice.展开更多
Background Several clinical trials have shown that sirolimus-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The FIREBIRD stent （coated with durable polyme...Background Several clinical trials have shown that sirolimus-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The FIREBIRD stent （coated with durable polymer） and the EXCEL stent （coated with bioabsorbable polymer） are two different types of sirolimus-eluting stents made in China; both have been approved for clinical use in China by the State Food and Drug Administration. The mid-term （6-month） angiographic and clinical results of both stents have been confirmed exciting perspective outcomes. However, it is unclear whether there are differences in the long-term safety and efficacy between the two types of stents in daily practice.Methods All consecutive patients undergoing elective PCI with EXCEL or FIREBIRD stents between June 1,2006 and December 31, 2006 at Fu Wai Hospital in Beijing were included. Patients were classified from the index admission according to stent types （EXCEL or FIREBIRD） used. Clinical and procedural risk factors were collected prospectively. With propensity score matching without replacement, the frequency of major adverse cardiac events （MACE, a composite of death, myocardial infarction or target vessel revascularization） and stent thrombosis during a 2-year follow-up period were compared between the two groups.Results A total of 474 patients were treated with EXCEL, and 640 were treated with FIREBIRD. Three hundred and ninety-seven EXCEL patients were matched to 397 FIREBIRD patients, 2-year risk-adjusted MACE rates were 6.1% in EXCEL group and 7.6% in FIREBIRD group （HR 0.84, 95%CI0.50-1.43）, whereas the respective rates for mortality, myocardial infarction and target-vessel revascularization were 2.3% vs 2.8% （HR 0.74, 95%CI0.30-0.85）, 1.8% vs 1.3% （HR 1.41,95%CI 0.45-4.43） and 2.5% vs 4.0% （HR 0.62, 95%CI0.28-0.37）, respectively. Cumulative incidence of stent thrombosis at 2 years was 1.8% in the EXCEL group vs 1.3% in the FIREBIRD group （P=0.5610）, whereas the rate of very late stent展开更多
A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analys...A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analysis and histopathological evaluation were carried out.The results showed that Ca–P coating could obviously improve the corrosion resistance of the pure Mg membrane.The in vivo results showed that Mg membrane coated with Ca–P would take 8 weeks to be completely absorbed.However, Mg membrane was completely absorbed within 1 week.Histopathological evaluation showed that the Ca–P-coated Mg membranes were significantly better than Ti membranes at the early implantation time(4 weeks), and with the time prolonging,the performance of the coated Mg membrane was not as good as pure Ti membranes(but still better than blank group) at 8 and 12 weeks.The coated biodegradable Mg membrane had a good promising application in GBR.But further studies have to be done to further decrease the degradation rate of pure Mg membrane.展开更多
A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method whi...A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method which combines 3D bio-printing and electrospinning to prepare the composite bioabsorbable vascular stent （CBVS） is proposed. The inner layer of the CBVS can be obtained through 3D bio- printing using poly-p-dioxanone （PPDO）. The thin nanofiber film that serves as the outer layer can be built through electrospinning using mixtures of chitosan-PVA （poly （vinyl alcohol））. Tests of mechanical properties show that the stent prepared through 3D bio-printing combined with electrospinning is better than that prepared through 3D bio- printing alone. Cells cultivated on the CBVS adhere and proliferate better due to the natural, biological chitosan in the outer layer. The proposed complex process and method can provide a good basis for preparing a controllable drug-carrying vascular stent. Overall, the CBVS can be a good candidate for treating stenotic vessels.展开更多
Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA)fibers were investigated during several industrial processing stages and in vitro degradation by means of wide-a...Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA)fibers were investigated during several industrial processing stages and in vitro degradation by means of wide-angle X-raydiffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the orientation stage, the PGAfibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similarconditions. In the hot-stretching and post-annealing stages, after fibers were braided, PGA samples were found to gain morecrystallinity and higher T_g than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate ofdegradation. DMA results showed that a great deal of internal stress that was built during orientation and hot-stretchingstages was released in the post-annealing stage for a1l PGA and PGA-co-PLA samples. During earlier stages of in vitrodegradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. Theheat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLAsamples, indicating the amorphous portions of the polymers lost orientation after a short period in the buffer solution, mostlikely due to relaxation of the cleaved chains.展开更多
Radial compressive property greatly influences nerve regeneration and functional recovery. In this study,four types of braided bioabsorbable nerve regeneration conduits made from poly(glycolide-co-L-lactide)(PGLA) wer...Radial compressive property greatly influences nerve regeneration and functional recovery. In this study,four types of braided bioabsorbable nerve regeneration conduits made from poly(glycolide-co-L-lactide)(PGLA) were produced. The aim is to test the radial compressive force and elastic recovery ratio of nerve regeneration conduits. The results indicated that radial compressive force was closely related to the inner diameter and length of tubes and elastic recovery ratio was nearly unaffected by these two factors.展开更多
A high Mw of PLLA was synthesized, it intended to be used in the manufacture ofbioabsorbable screw applied in bone fracture internal fixation. The optical reactionconditions have been discussed.
Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported...Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice. Methods Cobalt chromium based DES with bioabsorbable polymer （Simrex stent） as well as control stents （Polymer stent and EXCELTM stent） were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography （QCA） analysis, histomorphometry, and electron-microscopical follow-up were performed. Results A total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis （%DS）, late loss （LL）, and percent area stenosis （%AS） of Simrex was （12.9±0.4）%, （0.35±0.02） mm, and （24.5±4.2）%, respectively, without significant difference in comparison to commercialized EXCELTM stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4-12 weeks for Simrex to complete its re-endothelialization process. Conclusions Cobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.展开更多
The bare metal stent (BMS) used in the blood vessel caused the restenosis after the operation due to formation and proliferation of neointimal. Recently, as a method to overcome the problems of BMS, drug eluting stent...The bare metal stent (BMS) used in the blood vessel caused the restenosis after the operation due to formation and proliferation of neointimal. Recently, as a method to overcome the problems of BMS, drug eluting stent (DES) is developed and being applied to human body which has drug reducing restenosis applied on the metal surface. DES has the advantage of greatly reducing the restenosis after the operation;however, metal stent remains in the body after the drug is released causing issues such as late thrombosis and restenosis so that currently the attention is increasing for biodegradable materials that reduce restenosis and thrombosis by degrading as a certain amount of time passes after the drug is released by the stent material. In this review, the study trend of biodegradable stent will be explained.展开更多
文摘Background Several clinical trials have shown that rapamycin-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The Firebird stent and the Excel stent （coated with bioabsorbable polymer） are two different types of rapamycin-eluUng stents made in China, both have been recently approved for clinical use in China by State Food and Drug Administration. However, it is unclear whether there are differences in safety and efficacy between the two types of stents in daily practice. Methods In the month of June 2006, a total of 190 consecutive patients were treated exclusively with Firebird stents （n=93, Firebird group） or Excel stents （n=97, Excel group） in our center and were included in this study. The frequency of major adverse cardiac events （MACE, a composite of death, myocardial infarction or target lesion revascularization）, binary restenosis, and late lumen loss and stent thrombosis dudng a six-month follow-up period were compared between the two groups. Results Patient and lesion characteristics were comparable between the groups. Major adverse cardiac event rates were low in hospital and at 6 months （2.1% in the Excel group and 0% in the Firebird group, P〉 0.05）. The 6-month angiographic in-stent restenosis rate was 0% in both groups, with an associated late loss of （0.15 ± 0.21） mm versus （0.14 ± 0.20） mm （P=0.858） and the in-segment restenosis rate was also 0% for the Excel group and the Firebird group. There was no definite stent thrombosis identified in either group during the six-month follow-up period and only one patient in the Excel group had probable stent thrombosis in hospital. Conclusions Results from this mid-term, single-center study showed that both of the Firebird and the Excel rapamycin eluUng stent had similar effects on reducing the incidence of MACE and the risk of restenosis （both in-stent and in-segment binary restenosis） after PCI in daily practice.
文摘Background Several clinical trials have shown that sirolimus-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention （PCI）. The FIREBIRD stent （coated with durable polymer） and the EXCEL stent （coated with bioabsorbable polymer） are two different types of sirolimus-eluting stents made in China; both have been approved for clinical use in China by the State Food and Drug Administration. The mid-term （6-month） angiographic and clinical results of both stents have been confirmed exciting perspective outcomes. However, it is unclear whether there are differences in the long-term safety and efficacy between the two types of stents in daily practice.Methods All consecutive patients undergoing elective PCI with EXCEL or FIREBIRD stents between June 1,2006 and December 31, 2006 at Fu Wai Hospital in Beijing were included. Patients were classified from the index admission according to stent types （EXCEL or FIREBIRD） used. Clinical and procedural risk factors were collected prospectively. With propensity score matching without replacement, the frequency of major adverse cardiac events （MACE, a composite of death, myocardial infarction or target vessel revascularization） and stent thrombosis during a 2-year follow-up period were compared between the two groups.Results A total of 474 patients were treated with EXCEL, and 640 were treated with FIREBIRD. Three hundred and ninety-seven EXCEL patients were matched to 397 FIREBIRD patients, 2-year risk-adjusted MACE rates were 6.1% in EXCEL group and 7.6% in FIREBIRD group （HR 0.84, 95%CI0.50-1.43）, whereas the respective rates for mortality, myocardial infarction and target-vessel revascularization were 2.3% vs 2.8% （HR 0.74, 95%CI0.30-0.85）, 1.8% vs 1.3% （HR 1.41,95%CI 0.45-4.43） and 2.5% vs 4.0% （HR 0.62, 95%CI0.28-0.37）, respectively. Cumulative incidence of stent thrombosis at 2 years was 1.8% in the EXCEL group vs 1.3% in the FIREBIRD group （P=0.5610）, whereas the rate of very late stent
基金financially supported by the Key Program of China on Biomedical Materials Research and Tissue and Organ Replacement (Nos.2016YFC1101804 and 2016YFC1100604)Shenyang Key R&D and Technology Transfer Program (No.Z18-0-027)
文摘A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analysis and histopathological evaluation were carried out.The results showed that Ca–P coating could obviously improve the corrosion resistance of the pure Mg membrane.The in vivo results showed that Mg membrane coated with Ca–P would take 8 weeks to be completely absorbed.However, Mg membrane was completely absorbed within 1 week.Histopathological evaluation showed that the Ca–P-coated Mg membranes were significantly better than Ti membranes at the early implantation time(4 weeks), and with the time prolonging,the performance of the coated Mg membrane was not as good as pure Ti membranes(but still better than blank group) at 8 and 12 weeks.The coated biodegradable Mg membrane had a good promising application in GBR.But further studies have to be done to further decrease the degradation rate of pure Mg membrane.
基金The National Natural Science Foundation of China(No.51475281,51375292)the National Natural Science Foundation for Young Scholar of China(No.51105239)
文摘A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent （BVS）, a new method which combines 3D bio-printing and electrospinning to prepare the composite bioabsorbable vascular stent （CBVS） is proposed. The inner layer of the CBVS can be obtained through 3D bio- printing using poly-p-dioxanone （PPDO）. The thin nanofiber film that serves as the outer layer can be built through electrospinning using mixtures of chitosan-PVA （poly （vinyl alcohol））. Tests of mechanical properties show that the stent prepared through 3D bio-printing combined with electrospinning is better than that prepared through 3D bio- printing alone. Cells cultivated on the CBVS adhere and proliferate better due to the natural, biological chitosan in the outer layer. The proposed complex process and method can provide a good basis for preparing a controllable drug-carrying vascular stent. Overall, the CBVS can be a good candidate for treating stenotic vessels.
基金This research was made possible by a Johnson & Johnson CORD Internship Award funded by Ethicon. BH and BF thank the National Science Foundation for partial financial support (DMR-0098104).
文摘Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA)fibers were investigated during several industrial processing stages and in vitro degradation by means of wide-angle X-raydiffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the orientation stage, the PGAfibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similarconditions. In the hot-stretching and post-annealing stages, after fibers were braided, PGA samples were found to gain morecrystallinity and higher T_g than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate ofdegradation. DMA results showed that a great deal of internal stress that was built during orientation and hot-stretchingstages was released in the post-annealing stage for a1l PGA and PGA-co-PLA samples. During earlier stages of in vitrodegradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. Theheat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLAsamples, indicating the amorphous portions of the polymers lost orientation after a short period in the buffer solution, mostlikely due to relaxation of the cleaved chains.
基金supported by the National Key Research and Development Program(2022YFC2503400)the Fundamental Research Funds for the Central Universities(2019PT350005)+4 种基金the National Natural Science Foundation of China(81970444)the Beijing Municipal Science and Technology Project(Z201100005420030)the National High Level Talents Special Support Plan(2020-RSW02)the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2021-I2M-1-065)the Sanming Project of Medicine in Shenzhen(SZSM202011013)。
文摘Radial compressive property greatly influences nerve regeneration and functional recovery. In this study,four types of braided bioabsorbable nerve regeneration conduits made from poly(glycolide-co-L-lactide)(PGLA) were produced. The aim is to test the radial compressive force and elastic recovery ratio of nerve regeneration conduits. The results indicated that radial compressive force was closely related to the inner diameter and length of tubes and elastic recovery ratio was nearly unaffected by these two factors.
文摘A high Mw of PLLA was synthesized, it intended to be used in the manufacture ofbioabsorbable screw applied in bone fracture internal fixation. The optical reactionconditions have been discussed.
文摘Background First generation drug-eluting stents （DESs） were based on 316L stainless steel and coated with a permanent polymer. The vessel wall of these DESs was inflammatory and late in-stent thrombosis was reported. Hence, cobalt chromium based DES coated with a bioabsorbable polymer was an alternate choice. Methods Cobalt chromium based DES with bioabsorbable polymer （Simrex stent） as well as control stents （Polymer stent and EXCELTM stent） were implanted into porcine arteries. At a designated time, angiography, quantitative coronary angiography （QCA） analysis, histomorphometry, and electron-microscopical follow-up were performed. Results A total of 98 stents of all the three groups were harvested. At week 24, percent diameter stenosis （%DS）, late loss （LL）, and percent area stenosis （%AS） of Simrex was （12.9±0.4）%, （0.35±0.02） mm, and （24.5±4.2）%, respectively, without significant difference in comparison to commercialized EXCELTM stent. Slight inflammatory reaction was seen around the stent strut of Simrex, just as in the other two groups. Electron-microscopical follow-up suggested that it might take 4-12 weeks for Simrex to complete its re-endothelialization process. Conclusions Cobalt chromium based, bioabsorbable polymer coated sirolimus-eluting stent showed excellent biocompatibility. During 24 weeks observation in porcine model, it was proved that this novel DES system successfully inhibited neointima hyperplasia and decreased in-stent stenosis. It is feasible to launch a clinical evaluation to improve the current prognosis of DES implantation.
文摘The bare metal stent (BMS) used in the blood vessel caused the restenosis after the operation due to formation and proliferation of neointimal. Recently, as a method to overcome the problems of BMS, drug eluting stent (DES) is developed and being applied to human body which has drug reducing restenosis applied on the metal surface. DES has the advantage of greatly reducing the restenosis after the operation;however, metal stent remains in the body after the drug is released causing issues such as late thrombosis and restenosis so that currently the attention is increasing for biodegradable materials that reduce restenosis and thrombosis by degrading as a certain amount of time passes after the drug is released by the stent material. In this review, the study trend of biodegradable stent will be explained.
