Foreign body reactions induced by macrophages often cause delay or failure of wound healing in the application of tissue engineering scaffolds.This study explores the application of nanosilver(NAg)to reduce foreign bo...Foreign body reactions induced by macrophages often cause delay or failure of wound healing in the application of tissue engineering scaffolds.This study explores the application of nanosilver(NAg)to reduce foreign body reactions during scaffold transplantation.An NAg hybrid collagen-chitosan scaffold(NAg-CCS)was prepared using the freeze-drying method.The NAg-CCS was implanted on the back of rats to evaluate the effects on foreign body reactions.Skin tissue samples were collected for histological and immunological evaluation at variable intervals.Miniature pigs were used to assess the effects of NAg on skin wound healing.The wounds were photographed,and tissue samples were collected for molecular biological analysis at different time points post-transplantation.NAg-CCS has a porous structure and the results showed that it could release NAg constantly for two weeks.The NAg-CCS group rarely developed a foreign body reaction,while the blank-CCS group showed granulomas or necrosis in the subcutaneous grafting experiment.Both matrix metalloproteinase-1(MMP-1)and tissue inhibitor of metalloproteinase-1(TIMP-1)were reduced significantly in the NAg-CCS group.The NAg-CCS group had higher interleukin(IL)-10 and lower IL-6 than the blank CCS group.In the wound healing study,M1 macrophage activation and inflammatory-related proteins inducible nitric oxide synthase(iNOS),IL-6,and interferon-(IFN-)were inhibited by NAg.In contrast,M2 macrophage activation and proinflammatory proteins(arginase-1),major histocompatibility complex-II(MHC-II),and found in inflammatory zone-1(FIZZ-1)were promoted,and this was responsible for suppressing the foreign body responses and accelerating wound healing.In conclusion,dermal scaffolds containing NAg suppressed the foreign body reaction by regulating macrophages and the expression of inflammatory cytokines,thereby promoting wound healing.展开更多
Dermal substitutes provide a template for dermal regeneration and reconstruction.They constitutes an ideal clinical treatment for deep skin defects.However,rapid vascularization remains as a major hurdle to the develo...Dermal substitutes provide a template for dermal regeneration and reconstruction.They constitutes an ideal clinical treatment for deep skin defects.However,rapid vascularization remains as a major hurdle to the development and application of dermal substitutes.Several bioactive factors play an important regulatory role in the process of angiogenesis and an understanding of the mechanism of achieving their effective delivery and sustained function is vital.Nanomaterials have great potential for tissue engineering.Effective delivery of bioactive factors(including growth factors,peptides and nucleic acids)by nanomaterials is of increasing research interest.This paper discusses the process of dermal substitute angiogenesis and the roles of related bioactive factors in this process.The application of nanomaterials for the delivery of bioactive factors to enhance angiogenesis and accelerate wound healing is also reviewed.We focus on new systems and approaches for delivering bioactive factors for enhancing angiogenesis in dermal substitutes.展开更多
基金supported by the Zhejiang Province Key Research and Development Program(No.2019C03083)the Zhejiang Provincial Basic Public Welfare Research Program(No.LGF19H150008)the National Natural Science Foundation of China(Nos.81601681 and 81871558).
文摘Foreign body reactions induced by macrophages often cause delay or failure of wound healing in the application of tissue engineering scaffolds.This study explores the application of nanosilver(NAg)to reduce foreign body reactions during scaffold transplantation.An NAg hybrid collagen-chitosan scaffold(NAg-CCS)was prepared using the freeze-drying method.The NAg-CCS was implanted on the back of rats to evaluate the effects on foreign body reactions.Skin tissue samples were collected for histological and immunological evaluation at variable intervals.Miniature pigs were used to assess the effects of NAg on skin wound healing.The wounds were photographed,and tissue samples were collected for molecular biological analysis at different time points post-transplantation.NAg-CCS has a porous structure and the results showed that it could release NAg constantly for two weeks.The NAg-CCS group rarely developed a foreign body reaction,while the blank-CCS group showed granulomas or necrosis in the subcutaneous grafting experiment.Both matrix metalloproteinase-1(MMP-1)and tissue inhibitor of metalloproteinase-1(TIMP-1)were reduced significantly in the NAg-CCS group.The NAg-CCS group had higher interleukin(IL)-10 and lower IL-6 than the blank CCS group.In the wound healing study,M1 macrophage activation and inflammatory-related proteins inducible nitric oxide synthase(iNOS),IL-6,and interferon-(IFN-)were inhibited by NAg.In contrast,M2 macrophage activation and proinflammatory proteins(arginase-1),major histocompatibility complex-II(MHC-II),and found in inflammatory zone-1(FIZZ-1)were promoted,and this was responsible for suppressing the foreign body responses and accelerating wound healing.In conclusion,dermal scaffolds containing NAg suppressed the foreign body reaction by regulating macrophages and the expression of inflammatory cytokines,thereby promoting wound healing.
基金supported by the National key research and development project(2016YFC1100800,2016YFC1100803)the National Natural Science Foundation of China(81772069,81401591,81801911)the Zhejiang Provincial Basic Public Welfare Research Program(LGF19H150008).
文摘Dermal substitutes provide a template for dermal regeneration and reconstruction.They constitutes an ideal clinical treatment for deep skin defects.However,rapid vascularization remains as a major hurdle to the development and application of dermal substitutes.Several bioactive factors play an important regulatory role in the process of angiogenesis and an understanding of the mechanism of achieving their effective delivery and sustained function is vital.Nanomaterials have great potential for tissue engineering.Effective delivery of bioactive factors(including growth factors,peptides and nucleic acids)by nanomaterials is of increasing research interest.This paper discusses the process of dermal substitute angiogenesis and the roles of related bioactive factors in this process.The application of nanomaterials for the delivery of bioactive factors to enhance angiogenesis and accelerate wound healing is also reviewed.We focus on new systems and approaches for delivering bioactive factors for enhancing angiogenesis in dermal substitutes.
