Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15...Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15 Zr-7 Cu(TZC-7 A),after holding for 2 h at slightly above their beta transus temperature(BTT) ensured their tensile strength(UTS),yield strength(YS) and hardness(HRV) were improved by31.2%,20% and 12.3% respectively compared to the control without Cu,Ti-15 Zr(T-15 ZA).Although the3 wt.% Cu alloy displayed the highest elongation(26%),the TZC-7 A alloy also possessed a good ductility.Presence of evenly dispersed Ti2 Cu and Zr2 Cu Cu-rich intermetallic phases formed as interwoven and alternating lamellae within the α+β matrix as a result of Cu addition,as revealed by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).These greatly contributed to their strengthening and bactericidal properties.Over 98% antibacterial effect against E.coli and S.aureus have been imparted,coupled with excellent biofilm inhibition.Potentiodynamic polarization curves showed that the TZC-7 A alloy possessed higher corrosion resistance than commercially pure titanium,cp-Ti;contact angle test revealed enhanced hydrophilicity;while confocal laser scanning microscopy(CLSM) and cell counting kit(CCK-8) assays also displayed drastically lowered bacterial adhesion rate with comparatively no cytotoxicity.Cell attachment on all alloys was similar but the best spread was obtained on TZC-7 A after 24 h.The developed alloy has good potential as an antibacterial implant material with combination of optimized properties.展开更多
Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve ...Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical integrity.In this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(RGO)-calcium carbonate(CaCO_(3))composite coating.Detailed analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.展开更多
Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration(GBR)and are often made of resorbable collagen or non-resorbable materials such as PTFE.While collagen membranes do ...Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration(GBR)and are often made of resorbable collagen or non-resorbable materials such as PTFE.While collagen membranes do not provide sufficient mechanical protection of the covered bone defect,titanium reinforced membranes and non-resorbable membranes need to be removed in a second surgery.Thus,biodegradable GBR membranes made of pure magnesium might be an alternative.In this study a biodegradable pure magnesium(99.95%)membrane has been proven to have all of the necessary requirements for an optimal regenerative outcome from both a mechanical and biological perspective.After implantation,the magnesium membrane separates the regenerating bone from the overlying,faster proliferating soft tissue.During the initial healing period,the membrane maintained a barrier function and space provision,whilst retaining the positioning of the bone graft material within the defect space.As the magnesium metal corroded,it formed a salty corrosion layer and local gas cavities,both of which extended the functional lifespan of the membrane barrier capabilities.During the resorption of the magnesium metal and magnesium salts,it was observed that the membrane became surrounded and then replaced by new bone.After the membrane had completely resorbed,only healthy tissue remained.The in vivo performance study demonstrated that the magnesium membrane has a comparable healing response and tissue regeneration to that of a resorbable collagen membrane.Overall,the magnesium membrane demonstrated all of the ideal qualities for a barrier membrane used in GBR treatment.展开更多
An ideal fixation system for guided bone(GBR)regeneration in oral surgery must fulfil several criteria that includes the provision of adequate mechanical fixation,complete resorption when no longer needed,complete rep...An ideal fixation system for guided bone(GBR)regeneration in oral surgery must fulfil several criteria that includes the provision of adequate mechanical fixation,complete resorption when no longer needed,complete replacement by bone,as well as be biocompatible and have a good clinical manageability.For the first time,a biodegradable magnesium fixation screw made of the magnesium alloy WZM211 with a MgF2 coating has been designed and tested to fulfill these criteria.Adequate mechanical fixation was shown for the magnesium fixation screw in several benchtop tests that directly compared the magnesium fixation screw with an equivalent polymeric resorbable device.Results demonstrated slightly superior mechanical properties of the magnesium device in comparison to the polymeric device even after 4 weeks of degradation.Biocompatibility of the magnesium fixation screw was demonstrated in several in vitro and in vivo tests.Degradation of the magnesium screw was investigated in in vitro and in vivo tests,where it was found that the screw is resorbed slowly and completely after 52 weeks,providing adequate fixation in the early critical healing phase.Overall,the magnesium fixation screw demonstrates all of the key properties required for an ideal fixation screw of membranes used in guided bone regeneration(GBR)surgeries.展开更多
The successful application of magnesium(Mg)alloys as biodegradable bone substitutes for critical-sized defects may be comprised by their high degradation rate resulting in a loss of mechanical integrity.This study inv...The successful application of magnesium(Mg)alloys as biodegradable bone substitutes for critical-sized defects may be comprised by their high degradation rate resulting in a loss of mechanical integrity.This study investigates the degradation pattern of an open-porous fluoride-coated Mg-based scaffold immersed in circulating Hanks’Balanced Salt Solution(HBSS)with and without in situ cyclic compression(30 N/1 Hz).The changes in morphological and mechanical properties have been studied by combining in situ high-resolution X-ray computed tomography mechanics and digital volume correlation.Although in situ cyclic compression induced acceleration of the corrosion rate,probably due to local disruption of the coating layer where fatigue microcracks were formed,no critical failures in the overall scaffold were observed,indicating that the mechanical integrity of the Mg scaffolds was preserved.Structural changes,due to the accumulation of corrosion debris between the scaffold fibres,resulted in a significant increase(p<0.05)in the material volume fraction from 0.52±0.07 to 0.47±0.03 after 14 days of corrosion.However,despite an increase in fibre material loss,the accumulated corrosion products appear to have led to an increase in Young’s modulus after 14 days as well as lower third principal strain(εp3)accumulation(-91000±6361μεand-60093±2414μεafter 2 and 14 days,respectively).Therefore,this innovative Mg scaffold design and composition provide a bone replacement,capable of sustaining mechanical loads in situ during the postoperative phase allowing new bone formation to be initially supported as the scaffold resorbs.展开更多
Bacterial infectious diseases are one of the leading causes of death worldwide.Even with the use of multiple antibiotic treatment strategies,4.95 million people died from drug-resistant bacterial infections in 2019.By...Bacterial infectious diseases are one of the leading causes of death worldwide.Even with the use of multiple antibiotic treatment strategies,4.95 million people died from drug-resistant bacterial infections in 2019.By 2050,the number of deaths will reach 10 milion annually.The increasing mortality may be partly due to bacterial heterogeneity in the infection microenvironment,such as drug-resistant bacteria,biofilms,persister cells,intracellular bacteria,and small colony variants.In addition,the complexity of the immune microenvironment at different stages of infection makes biomaterials with direct antimicrobial activity unsatisfactory for the longterm treatment of chronic bacterial infections.The increasing mortality may be partly attributed to the biomaterials failing to modulate the active antimicrobial action of immune cells.Therefore,there is an urgent need for effective alternatives to treat bacterial infections.Accordingly,the development of immunomodulatory antimicrobial biomaterials has recently received considerable interest;however,a comprehensive review of their research progress is lacking.In this review,we focus mainly on the research progress and future perspectives of immunomodulatory antimicrobial biomaterials used at different stages of infection.First,we describe the characteristics of the immune microenvironment in the acute and chronic phases of bacterial infections.Then,we highlight the immunomodulatory strategies for antimicrobial biomaterials at different stages of infection and their corresponding advantages and disadvantages.Moreover,we discuss biomaterial-mediated bacterial vaccines'potential applications and challenges for activating innate and adaptive immune memory.This review will serve as a reference for future studies to develop next-generation immunomodulatory biomaterials and accelerate their translation into clinical practice.展开更多
Magnesium as biodegradable biomaterial could serve as bone augmentation material in implant dentistry.The knowledge about the predictability of the biodegradation process is essential as this process needs to go hand ...Magnesium as biodegradable biomaterial could serve as bone augmentation material in implant dentistry.The knowledge about the predictability of the biodegradation process is essential as this process needs to go hand in hand with the formation of new bone to gradually replace the augmentation material.Therefore,this work aimed to assess if the electrochemistry(EC)measurements of the corrosion process correlate with the surface features at various time points during the surface degradation,in order to describe the degradation process of Mg and Mg alloys more reliably,under the assumption that differences in EC behavior can be detected and related to specific patterns on the surface.In this test setup,a special optical chamber was used for electrochemical measurements on Mg and Mg-alloys(Mg2Ag,Mg4Ag,and Mg6Ag).Specimens were investigated using different circulating cell culture solutions as electrolytes,these were minimum essential medium(MEM),Hank’s Balanced Salt Solution(HBSS),and MEM+(MEM with added sodium hydrogen carbonate)at 37℃.Open circuit potential measurements(OCP)over 30 min followed by cyclic polarization were performed.The electrochemistry data,including OCP,exchange current density and corrosion potential,were compared with visible changes at the surface during these treatments over time.The results show that the addition of silver(Ag)leads to a“standardization”of the degradation regardless of the selected test medium.It is currently difficult to correlate the visible microscopic changes with the data taken from the measurements.Therefore,further investigations are necessary.展开更多
In clinical trials,cell therapy,especially mesenchymal stem cells(MSC),contributed to wound treatment options in an innovative way.While,there are some limitations of MSC during the application process,including stric...In clinical trials,cell therapy,especially mesenchymal stem cells(MSC),contributed to wound treatment options in an innovative way.While,there are some limitations of MSC during the application process,including strict maintenance requirements and unpredictable differentiation.In order to expand the scope of application and reduce the restrictions related to direct use of SMC,the mechanisms of stem cells need to be studied.The latest research found that the effect of cell therapy is achieved mainly through paracrine effects,and the major bioactive vesicles which responsible for the paracrine effects is exosome.Exosome is a kind of extracellular membrane vesicle,which secreted from various cells and contain proteins,lipids and nucleic acids,to coordinate intercellular communication.In this review,the main cells type and cytokines relevant to every healing stage has been discussed,and the research about MSC-derived exosomes that has therapeutic effects has been summarized.At last,the potential application of exosomes as a bioactive material in the treatment of wound healing and related challenges as well as its possible solutions are discussed to reveal highly effective therapeutic strategies.展开更多
Bioactive Materials is reporting about international events which may promote biomaterial research beyond national borders.In this regard,both countries,Germany and China have become global players in the field of hea...Bioactive Materials is reporting about international events which may promote biomaterial research beyond national borders.In this regard,both countries,Germany and China have become global players in the field of health economy in the last decades.A sino-german platform for life sciences has already been founded in the field of health economy that enables for more cooperative projects between both research and economy from both nations.Thus,many different research projects have already been conducted between both countries.However,cooperation between researchers,clinicians and industry of different disciplines and fields is especially essential for the progress in biomaterial research and related products.Chemists,material scientists,biologists and physicians amongst many others are participating in this research field and are ambitious to find mutual solutions for the regeneration of various tissues.This collaborative research and the markets for biomedical products become more and more global and,thus,programs to sustained established cooperative research are desirable.展开更多
基金supported financially by the National Key Research and Development Program of China (Nos. 2018YFC1106601 and 2016YFC1100600)National Natural Science Foundation (No. 51631009)+2 种基金Youth Innovation Promotion Association, CAS (No. 2014168)Promoting Liaoning Province Talents Program-Top Young Talents (XLYC1807069)the support of CAS-TWAS President Fellowship。
文摘Ti-15 Zr-xCu(3≤x≤7,wt.%) novel antibacterial and antibiofilm alloys with competitive mechanical properties,biological responses and corrosion resistance were designed and fabricated.Annealing heat treatment on Ti-15 Zr-7 Cu(TZC-7 A),after holding for 2 h at slightly above their beta transus temperature(BTT) ensured their tensile strength(UTS),yield strength(YS) and hardness(HRV) were improved by31.2%,20% and 12.3% respectively compared to the control without Cu,Ti-15 Zr(T-15 ZA).Although the3 wt.% Cu alloy displayed the highest elongation(26%),the TZC-7 A alloy also possessed a good ductility.Presence of evenly dispersed Ti2 Cu and Zr2 Cu Cu-rich intermetallic phases formed as interwoven and alternating lamellae within the α+β matrix as a result of Cu addition,as revealed by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).These greatly contributed to their strengthening and bactericidal properties.Over 98% antibacterial effect against E.coli and S.aureus have been imparted,coupled with excellent biofilm inhibition.Potentiodynamic polarization curves showed that the TZC-7 A alloy possessed higher corrosion resistance than commercially pure titanium,cp-Ti;contact angle test revealed enhanced hydrophilicity;while confocal laser scanning microscopy(CLSM) and cell counting kit(CCK-8) assays also displayed drastically lowered bacterial adhesion rate with comparatively no cytotoxicity.Cell attachment on all alloys was similar but the best spread was obtained on TZC-7 A after 24 h.The developed alloy has good potential as an antibacterial implant material with combination of optimized properties.
文摘Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical integrity.In this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(RGO)-calcium carbonate(CaCO_(3))composite coating.Detailed analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.
文摘Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration(GBR)and are often made of resorbable collagen or non-resorbable materials such as PTFE.While collagen membranes do not provide sufficient mechanical protection of the covered bone defect,titanium reinforced membranes and non-resorbable membranes need to be removed in a second surgery.Thus,biodegradable GBR membranes made of pure magnesium might be an alternative.In this study a biodegradable pure magnesium(99.95%)membrane has been proven to have all of the necessary requirements for an optimal regenerative outcome from both a mechanical and biological perspective.After implantation,the magnesium membrane separates the regenerating bone from the overlying,faster proliferating soft tissue.During the initial healing period,the membrane maintained a barrier function and space provision,whilst retaining the positioning of the bone graft material within the defect space.As the magnesium metal corroded,it formed a salty corrosion layer and local gas cavities,both of which extended the functional lifespan of the membrane barrier capabilities.During the resorption of the magnesium metal and magnesium salts,it was observed that the membrane became surrounded and then replaced by new bone.After the membrane had completely resorbed,only healthy tissue remained.The in vivo performance study demonstrated that the magnesium membrane has a comparable healing response and tissue regeneration to that of a resorbable collagen membrane.Overall,the magnesium membrane demonstrated all of the ideal qualities for a barrier membrane used in GBR treatment.
文摘An ideal fixation system for guided bone(GBR)regeneration in oral surgery must fulfil several criteria that includes the provision of adequate mechanical fixation,complete resorption when no longer needed,complete replacement by bone,as well as be biocompatible and have a good clinical manageability.For the first time,a biodegradable magnesium fixation screw made of the magnesium alloy WZM211 with a MgF2 coating has been designed and tested to fulfill these criteria.Adequate mechanical fixation was shown for the magnesium fixation screw in several benchtop tests that directly compared the magnesium fixation screw with an equivalent polymeric resorbable device.Results demonstrated slightly superior mechanical properties of the magnesium device in comparison to the polymeric device even after 4 weeks of degradation.Biocompatibility of the magnesium fixation screw was demonstrated in several in vitro and in vivo tests.Degradation of the magnesium screw was investigated in in vitro and in vivo tests,where it was found that the screw is resorbed slowly and completely after 52 weeks,providing adequate fixation in the early critical healing phase.Overall,the magnesium fixation screw demonstrates all of the key properties required for an ideal fixation screw of membranes used in guided bone regeneration(GBR)surgeries.
文摘The successful application of magnesium(Mg)alloys as biodegradable bone substitutes for critical-sized defects may be comprised by their high degradation rate resulting in a loss of mechanical integrity.This study investigates the degradation pattern of an open-porous fluoride-coated Mg-based scaffold immersed in circulating Hanks’Balanced Salt Solution(HBSS)with and without in situ cyclic compression(30 N/1 Hz).The changes in morphological and mechanical properties have been studied by combining in situ high-resolution X-ray computed tomography mechanics and digital volume correlation.Although in situ cyclic compression induced acceleration of the corrosion rate,probably due to local disruption of the coating layer where fatigue microcracks were formed,no critical failures in the overall scaffold were observed,indicating that the mechanical integrity of the Mg scaffolds was preserved.Structural changes,due to the accumulation of corrosion debris between the scaffold fibres,resulted in a significant increase(p<0.05)in the material volume fraction from 0.52±0.07 to 0.47±0.03 after 14 days of corrosion.However,despite an increase in fibre material loss,the accumulated corrosion products appear to have led to an increase in Young’s modulus after 14 days as well as lower third principal strain(εp3)accumulation(-91000±6361μεand-60093±2414μεafter 2 and 14 days,respectively).Therefore,this innovative Mg scaffold design and composition provide a bone replacement,capable of sustaining mechanical loads in situ during the postoperative phase allowing new bone formation to be initially supported as the scaffold resorbs.
基金National Natural Science Foundation of China(grant nos.32222042,82225031,82172464,82172453,and 81972086)Shanghai Rising-Star Pro-gram(21QA1405500)Program of Shanghai Excellent Academic Leader(grant no.22XD1401900).
文摘Bacterial infectious diseases are one of the leading causes of death worldwide.Even with the use of multiple antibiotic treatment strategies,4.95 million people died from drug-resistant bacterial infections in 2019.By 2050,the number of deaths will reach 10 milion annually.The increasing mortality may be partly due to bacterial heterogeneity in the infection microenvironment,such as drug-resistant bacteria,biofilms,persister cells,intracellular bacteria,and small colony variants.In addition,the complexity of the immune microenvironment at different stages of infection makes biomaterials with direct antimicrobial activity unsatisfactory for the longterm treatment of chronic bacterial infections.The increasing mortality may be partly attributed to the biomaterials failing to modulate the active antimicrobial action of immune cells.Therefore,there is an urgent need for effective alternatives to treat bacterial infections.Accordingly,the development of immunomodulatory antimicrobial biomaterials has recently received considerable interest;however,a comprehensive review of their research progress is lacking.In this review,we focus mainly on the research progress and future perspectives of immunomodulatory antimicrobial biomaterials used at different stages of infection.First,we describe the characteristics of the immune microenvironment in the acute and chronic phases of bacterial infections.Then,we highlight the immunomodulatory strategies for antimicrobial biomaterials at different stages of infection and their corresponding advantages and disadvantages.Moreover,we discuss biomaterial-mediated bacterial vaccines'potential applications and challenges for activating innate and adaptive immune memory.This review will serve as a reference for future studies to develop next-generation immunomodulatory biomaterials and accelerate their translation into clinical practice.
文摘Magnesium as biodegradable biomaterial could serve as bone augmentation material in implant dentistry.The knowledge about the predictability of the biodegradation process is essential as this process needs to go hand in hand with the formation of new bone to gradually replace the augmentation material.Therefore,this work aimed to assess if the electrochemistry(EC)measurements of the corrosion process correlate with the surface features at various time points during the surface degradation,in order to describe the degradation process of Mg and Mg alloys more reliably,under the assumption that differences in EC behavior can be detected and related to specific patterns on the surface.In this test setup,a special optical chamber was used for electrochemical measurements on Mg and Mg-alloys(Mg2Ag,Mg4Ag,and Mg6Ag).Specimens were investigated using different circulating cell culture solutions as electrolytes,these were minimum essential medium(MEM),Hank’s Balanced Salt Solution(HBSS),and MEM+(MEM with added sodium hydrogen carbonate)at 37℃.Open circuit potential measurements(OCP)over 30 min followed by cyclic polarization were performed.The electrochemistry data,including OCP,exchange current density and corrosion potential,were compared with visible changes at the surface during these treatments over time.The results show that the addition of silver(Ag)leads to a“standardization”of the degradation regardless of the selected test medium.It is currently difficult to correlate the visible microscopic changes with the data taken from the measurements.Therefore,further investigations are necessary.
基金funded by the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1804251)National Key Research and Development Program of China(2017YFB0702500,2018YFC1106703 and 2016YFC1102403)Innovation and Entrepreneurship Program for College Students(2021cxcy564).
文摘In clinical trials,cell therapy,especially mesenchymal stem cells(MSC),contributed to wound treatment options in an innovative way.While,there are some limitations of MSC during the application process,including strict maintenance requirements and unpredictable differentiation.In order to expand the scope of application and reduce the restrictions related to direct use of SMC,the mechanisms of stem cells need to be studied.The latest research found that the effect of cell therapy is achieved mainly through paracrine effects,and the major bioactive vesicles which responsible for the paracrine effects is exosome.Exosome is a kind of extracellular membrane vesicle,which secreted from various cells and contain proteins,lipids and nucleic acids,to coordinate intercellular communication.In this review,the main cells type and cytokines relevant to every healing stage has been discussed,and the research about MSC-derived exosomes that has therapeutic effects has been summarized.At last,the potential application of exosomes as a bioactive material in the treatment of wound healing and related challenges as well as its possible solutions are discussed to reveal highly effective therapeutic strategies.
文摘Bioactive Materials is reporting about international events which may promote biomaterial research beyond national borders.In this regard,both countries,Germany and China have become global players in the field of health economy in the last decades.A sino-german platform for life sciences has already been founded in the field of health economy that enables for more cooperative projects between both research and economy from both nations.Thus,many different research projects have already been conducted between both countries.However,cooperation between researchers,clinicians and industry of different disciplines and fields is especially essential for the progress in biomaterial research and related products.Chemists,material scientists,biologists and physicians amongst many others are participating in this research field and are ambitious to find mutual solutions for the regeneration of various tissues.This collaborative research and the markets for biomedical products become more and more global and,thus,programs to sustained established cooperative research are desirable.
