Thrombogenesis remains the primary failure of synthetic vascular grafts.Endothelial coverage is crucial to provide an antithrombogenic surface.However,most synthetic materials do not support cell adhesion,and transana...Thrombogenesis remains the primary failure of synthetic vascular grafts.Endothelial coverage is crucial to provide an antithrombogenic surface.However,most synthetic materials do not support cell adhesion,and transanastomotic endothelial migration is limited.Here,a surface modification strategy using fucoidan and topography was developed to enable fast in situ endothelialization of polyvinyl alcohol,which is not endothelial cell-adhesive.Among three different immobilization approaches compared,conjugation of aminated-fucoidan promoted endothelial monolayer formation while minimizing thrombogenicity in both in vitro platelet rich plasma testing and ex vivo non-human primate shunt assay.Screening of six topographical patterns showed that 2μm gratings increased endothelial cell migration without inducing inflammation responses of endothelial cells.Mechanistic studies demonstrated that fucoidan could attract fibronectin,enabling integrin binding and focal adhesion formation and activating focal adhesion kinase(FAK)signaling,and 2μm gratings further enhanced FAK-mediated cell migration.In a clinically relevant rabbit carotid artery end-to-side anastomosis model,60%in situ endothelialization was observed throughout the entire lumen of 1.7 mm inner diameter modified grafts,compared to 0%of unmodified graft,and the four-week graft patency also increased.This work presents a promising strategy to stimulate in situ endothelialization on synthetic materials for improving long-term performance.展开更多
More than 50 years have passed since it was first recognized that the surface properties, and predominantly the surface energies of materials controlled their interactions with all biological phases via their spontane...More than 50 years have passed since it was first recognized that the surface properties, and predominantly the surface energies of materials controlled their interactions with all biological phases via their spontaneous acquisition of proteinaceous “conditioning films” of differing degrees of denaturation but usually of the same substances within any given system. This led to the understanding that useful engineering control of such interactions could thus be manifested through adjustments to those surface properties, giving significant control and utility to the biomaterials developer without requiring detailed discovery of the biological specifications of the components involved. Thus, effective selection of adhesive versus abhesive (non-stick, non-retention) outcomes for such useful appliances as dental implants versus substitute blood vessels, or water-resistant bonded structures versus clean, nontoxic ship bottoms is now facilitated with little biological background required. A historical overview is presented, followed by a brief survey of the forces involved and most useful analyses applied. Utility for blood-contacting materials is described in contrast to utility for bone- and tissue-contacting materials, demonstrating practical uses in controlling cell-surface interactions and preventing biofouling. New research directions being explored are noted, urging applications of this prior knowledge to replace the use of toxicants.展开更多
Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generat...Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generation was reported to realize up-regulation of cyclic guanosine monophosphate(c GMP)and improve hemocompatibility for diverse metal materials.We first introduce the active centre selenocysteine of glutathione peroxidase(GPx)to the self-assembling peptide(RADA)4,obtaining a functionalized hydrogel.Then the hydrogel is directly coated on the 316L stainless steel(SS)for catalytically generating NO from endogenous s-nitrosothiols(RSNO).The generated NO endows the coated surface with regulation of platelet behavior and reduction of plasmatic coagulation activation and complement system activation,hence improving antithrombotic ability in vitro and ex vivo.Overall,our NO-generating hydrogel coating surface engineering strategy provides a novel solution to remove the obstacle about thrombosis of blood-contacting devices in clinic.展开更多
Antibacterial extract-coated catheters are promising alternatives to their conventional counterparts,but their hemocompatibility and thermal stability must be studied.Nosocomial bacteria have developed resistance to c...Antibacterial extract-coated catheters are promising alternatives to their conventional counterparts,but their hemocompatibility and thermal stability must be studied.Nosocomial bacteria have developed resistance to conventional antibiotics.Herein,the minimum inhibitory but non-hemolytic concentration(MIC-NH)and the thermal stability of Larrea tridentata(L.tridentata)and Origanum vulgare(O.vulgare)extract-coated catheters were studied.Besides,plasma pretreatment was performed to enhance the extract adhesion.Briefly,the extract-coated catheters prevent Staphylococcus aureus colonization without causing hemolysis by using L.tridentata and O.vulgare extracts at MIC-NH(5000 and 2500μg ml~(-1),respectively).Moreover,it has been discovered that the extract coating and plasma treatment improved the thermal stability and the extract adhesion,respectively.Thus,this study provides evidence of alternative antibacterial but non-hemolytic extract-coated catheters.展开更多
Thrombus formation in the artificial heart blood pump is a complex problem. The most important factor of thrombosis in the blood pump is the quality of blood contacting surface which is related to hemocompatibility of...Thrombus formation in the artificial heart blood pump is a complex problem. The most important factor of thrombosis in the blood pump is the quality of blood contacting surface which is related to hemocompatibility of materials and micromorphololgy or roughness of the surface. So it is necessary to understand the morphology of the surface inside of blood pump in order to develop and improve a good quality blood pump. The authors observed and analysed the inner surface of blood pumps (both preimplanted and postimplanted) with scanning electron microscopy (SEM) providing a means for evaluating the blood pumps and for developing good quality of blood pumps. It was observed that there were four kinds of surface defects on the inner surface of the blood pumps: air bubble domes, open bubble craters, contaminated dust and gel particles. Microcrakes had also been found on the diaphragm of the postimplanted pump. But in the newly improved blood pump that had been imlanted for 16 days, there were few defects on the blood contacting surface, and only a little fibrinous layer observed. It could be considered that the current design and modifications are reasonable. Since some problems associated with the surface defects and thrombosis still existed, further improvement in fabrication process and quality control procedures with SEM are under way.展开更多
基金This work was supported by the National Institutes of Health grants[NIH R01HL130274 and R01HL144113]NSERC-CREATE Training in Global Biomedical Technology Research and Innovation at the University of Waterloo[CREATE-509950-2018]+2 种基金Canada Foundation for Innovation(CFI35573)NSERC Research Tools and Instruments Fund(RTI-2018-00220)the Oregon National Primate Research Center NIH grant award[P51OD011092].
文摘Thrombogenesis remains the primary failure of synthetic vascular grafts.Endothelial coverage is crucial to provide an antithrombogenic surface.However,most synthetic materials do not support cell adhesion,and transanastomotic endothelial migration is limited.Here,a surface modification strategy using fucoidan and topography was developed to enable fast in situ endothelialization of polyvinyl alcohol,which is not endothelial cell-adhesive.Among three different immobilization approaches compared,conjugation of aminated-fucoidan promoted endothelial monolayer formation while minimizing thrombogenicity in both in vitro platelet rich plasma testing and ex vivo non-human primate shunt assay.Screening of six topographical patterns showed that 2μm gratings increased endothelial cell migration without inducing inflammation responses of endothelial cells.Mechanistic studies demonstrated that fucoidan could attract fibronectin,enabling integrin binding and focal adhesion formation and activating focal adhesion kinase(FAK)signaling,and 2μm gratings further enhanced FAK-mediated cell migration.In a clinically relevant rabbit carotid artery end-to-side anastomosis model,60%in situ endothelialization was observed throughout the entire lumen of 1.7 mm inner diameter modified grafts,compared to 0%of unmodified graft,and the four-week graft patency also increased.This work presents a promising strategy to stimulate in situ endothelialization on synthetic materials for improving long-term performance.
文摘More than 50 years have passed since it was first recognized that the surface properties, and predominantly the surface energies of materials controlled their interactions with all biological phases via their spontaneous acquisition of proteinaceous “conditioning films” of differing degrees of denaturation but usually of the same substances within any given system. This led to the understanding that useful engineering control of such interactions could thus be manifested through adjustments to those surface properties, giving significant control and utility to the biomaterials developer without requiring detailed discovery of the biological specifications of the components involved. Thus, effective selection of adhesive versus abhesive (non-stick, non-retention) outcomes for such useful appliances as dental implants versus substitute blood vessels, or water-resistant bonded structures versus clean, nontoxic ship bottoms is now facilitated with little biological background required. A historical overview is presented, followed by a brief survey of the forces involved and most useful analyses applied. Utility for blood-contacting materials is described in contrast to utility for bone- and tissue-contacting materials, demonstrating practical uses in controlling cell-surface interactions and preventing biofouling. New research directions being explored are noted, urging applications of this prior knowledge to replace the use of toxicants.
基金financially supported by the National Natural Science Foundation of China(Nos.82072072,32171326 and 31800795)the International Cooperation Project by the Science and Technology Department of Sichuan Province(No.2021YFH0056)+1 种基金the Sichuan Science and Technology Program(No.2021JDRC0160)the High-level Talents Research and Development Program of Affiliated Dongguan Hospital(No.K202102)。
文摘Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generation was reported to realize up-regulation of cyclic guanosine monophosphate(c GMP)and improve hemocompatibility for diverse metal materials.We first introduce the active centre selenocysteine of glutathione peroxidase(GPx)to the self-assembling peptide(RADA)4,obtaining a functionalized hydrogel.Then the hydrogel is directly coated on the 316L stainless steel(SS)for catalytically generating NO from endogenous s-nitrosothiols(RSNO).The generated NO endows the coated surface with regulation of platelet behavior and reduction of plasmatic coagulation activation and complement system activation,hence improving antithrombotic ability in vitro and ex vivo.Overall,our NO-generating hydrogel coating surface engineering strategy provides a novel solution to remove the obstacle about thrombosis of blood-contacting devices in clinic.
基金the grant(No.CVU 859503)given to the first author to pursue his doctorate in Materials Science and Technology at the Autonomous University of Coahuila(UAdeC)FONCYT-Fund Destined to Promote the Development of Science and Technology in the State of Coahuila(No.COAH-2020-C14-C058)。
文摘Antibacterial extract-coated catheters are promising alternatives to their conventional counterparts,but their hemocompatibility and thermal stability must be studied.Nosocomial bacteria have developed resistance to conventional antibiotics.Herein,the minimum inhibitory but non-hemolytic concentration(MIC-NH)and the thermal stability of Larrea tridentata(L.tridentata)and Origanum vulgare(O.vulgare)extract-coated catheters were studied.Besides,plasma pretreatment was performed to enhance the extract adhesion.Briefly,the extract-coated catheters prevent Staphylococcus aureus colonization without causing hemolysis by using L.tridentata and O.vulgare extracts at MIC-NH(5000 and 2500μg ml~(-1),respectively).Moreover,it has been discovered that the extract coating and plasma treatment improved the thermal stability and the extract adhesion,respectively.Thus,this study provides evidence of alternative antibacterial but non-hemolytic extract-coated catheters.
文摘Thrombus formation in the artificial heart blood pump is a complex problem. The most important factor of thrombosis in the blood pump is the quality of blood contacting surface which is related to hemocompatibility of materials and micromorphololgy or roughness of the surface. So it is necessary to understand the morphology of the surface inside of blood pump in order to develop and improve a good quality blood pump. The authors observed and analysed the inner surface of blood pumps (both preimplanted and postimplanted) with scanning electron microscopy (SEM) providing a means for evaluating the blood pumps and for developing good quality of blood pumps. It was observed that there were four kinds of surface defects on the inner surface of the blood pumps: air bubble domes, open bubble craters, contaminated dust and gel particles. Microcrakes had also been found on the diaphragm of the postimplanted pump. But in the newly improved blood pump that had been imlanted for 16 days, there were few defects on the blood contacting surface, and only a little fibrinous layer observed. It could be considered that the current design and modifications are reasonable. Since some problems associated with the surface defects and thrombosis still existed, further improvement in fabrication process and quality control procedures with SEM are under way.
