Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional sutures.In the present...Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional sutures.In the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as control.The shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after operation.The Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to failure.Gross observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture groups.In the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks postoperatively.The collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous enthesis.In vivo degradation of the magnesium alloy wire was completed within 12 weeks.The results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.展开更多
采用湿喷丸技术处理铝合金表面,研究喷丸强度对2219铝合金扩散连接的影响。结果表明:随着喷丸强度的提高,表面粗糙度由0.1 mm N的1.917μm增加到0.3 mm N的3.401μm,且过大的喷丸强度易导致表面出现轻微的剥落损伤现象;喷丸强化提供的...采用湿喷丸技术处理铝合金表面,研究喷丸强度对2219铝合金扩散连接的影响。结果表明:随着喷丸强度的提高,表面粗糙度由0.1 mm N的1.917μm增加到0.3 mm N的3.401μm,且过大的喷丸强度易导致表面出现轻微的剥落损伤现象;喷丸强化提供的残余应力场可以促进界面的扩散连接过程,一方面加速溶质原子扩散并在界面聚集成相且与氧化物产生交互作用;另一方面促进再结晶晶粒形成,利用新晶界的动态迁移过程消除原始界面,两者共同作用提升了界面的愈合效果,0.1 mm N时界面剪切强度可由无喷丸的12.6 MPa提升至41.1 MPa。展开更多
Electrospun fibers,with proven ability to promote tissue regeneration,are widely being explored for rotator cuff repairing.However,without post treatment,the microstructure of the electrospun scaffold is vastly differ...Electrospun fibers,with proven ability to promote tissue regeneration,are widely being explored for rotator cuff repairing.However,without post treatment,the microstructure of the electrospun scaffold is vastly different from that of natural extracellular matrix(ECM).Moreover,during mechanical loading,the nanofibers slip that hampers the proliferation and differentiation of migrating stem cells.Here,electrospun nanofiber scaffolds,with crimped nanofibers and welded joints to biomimic the intricate natural microstructure of tendon-to-bone insertion,were prepared using poly(ester-urethane)urea and gelatin via electrospinning and double crosslinking by a multi-bonding network densification strategy.The crimped nanofiber scaffold(CNS)features bionic tensile stress and induces chondrogenic differentiation,laying credible basis for in vivo experimentation.After repairing a rabbit massive rotator cuff tear using a CNS for 3 months,the continuous translational tendon-to-bone interface was fully regenerated,and fatty infiltration was simultaneously inhibited.Instead of micro-CT,μCT was employed to visualize the integrity and intricateness of the three-dimensional microstructure of the CNS-induced-healed tendon-to-bone interface at an ultra-high resolution of less than 1μm.This study sheds light on the correlation between nanofiber post treatment and massive rotator cuff repair and provides a general strategy for crimped nanofiber preparation and tendon-to-bone interface imaging characterization.展开更多
Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properti...Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properties with values close to the human bone.Unfortunately,the implant surface must be adequately tuned,or Mg-based alloys must be alloyed with other chemical elements due to their increased corrosion effect in physiological media.This article reviews the clinical challenges related to bone repair and regeneration,classifying bone defects and presenting some of the most used and modern therapies for bone injuries,such as Ilizarov or Masquelet techniques or stem cell treatments.The implant interface challenges are related to new bone formation and fracture healing,implant degradation and hydrogen release.A detailed analysis of mechanical properties during implant degradation is extensively described based on different literature studies that included in vitro and in vivo tests correlated with material properties’characterization.Mg-based trauma implants such as plates and screws,intramedullary nails,Herbert screws,spine cages,rings for joint treatment and regenerative scaffolds are presented,taking into consideration their manufacturing technology,the implant geometrical dimensions and shape,the type of in vivo or in vitro studies and fracture localization.Modern technologies that modify or adapt the Mg-based implant interfaces are described by presenting the main surface microstructural modifications,physical deposition and chemical conversion coatings.The last part of the article provides some recommendations from a translational perspective,identifies the challenges associated with Mg-based implants and presents some future opportunities.This review outlines the available literature on trauma and regenerative bone implants and describes the main techniques used to control the alloy corrosion rate and the cellular environment of the implant.展开更多
基金the National Key Research and Development Program of China(No.2020YFC1107501)the National Natural Science Foundation of China(No.51971222,51801220)+4 种基金the Natural Science Foundation of Liaoning Province of China(No.2020-MS-001)the Dong Guan Innovative Research Team Program(No.2020607134012)the Military Translational Medicine Fund of Chinese PLA General Hospital(ZH19008)Capital’s Funds for Health Improvement and Research(CFH 2022-2-5051)the Dong Guan Science and Technology Service Network Initiative(20201600200042)。
文摘Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional sutures.In the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as control.The shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after operation.The Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to failure.Gross observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture groups.In the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks postoperatively.The collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous enthesis.In vivo degradation of the magnesium alloy wire was completed within 12 weeks.The results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.
文摘采用湿喷丸技术处理铝合金表面,研究喷丸强度对2219铝合金扩散连接的影响。结果表明:随着喷丸强度的提高,表面粗糙度由0.1 mm N的1.917μm增加到0.3 mm N的3.401μm,且过大的喷丸强度易导致表面出现轻微的剥落损伤现象;喷丸强化提供的残余应力场可以促进界面的扩散连接过程,一方面加速溶质原子扩散并在界面聚集成相且与氧化物产生交互作用;另一方面促进再结晶晶粒形成,利用新晶界的动态迁移过程消除原始界面,两者共同作用提升了界面的愈合效果,0.1 mm N时界面剪切强度可由无喷丸的12.6 MPa提升至41.1 MPa。
基金supported by Instrumental Analysis Center of Shanghai Jiao Tong University.This work was supported by the National Natural Science Foundation of China[Grant No.81902186,81671920,31972923,81871753,81772341]National Key Research and Development Program of China[Grant No.2018YFC1106200,2018YFC1106201,2018YFC1106202]Technology Support Project of Science and Technology Commission of Shanghai Municipality of China[Grant No.19441901700,19441901701,19441901702,18441902800].
文摘Electrospun fibers,with proven ability to promote tissue regeneration,are widely being explored for rotator cuff repairing.However,without post treatment,the microstructure of the electrospun scaffold is vastly different from that of natural extracellular matrix(ECM).Moreover,during mechanical loading,the nanofibers slip that hampers the proliferation and differentiation of migrating stem cells.Here,electrospun nanofiber scaffolds,with crimped nanofibers and welded joints to biomimic the intricate natural microstructure of tendon-to-bone insertion,were prepared using poly(ester-urethane)urea and gelatin via electrospinning and double crosslinking by a multi-bonding network densification strategy.The crimped nanofiber scaffold(CNS)features bionic tensile stress and induces chondrogenic differentiation,laying credible basis for in vivo experimentation.After repairing a rabbit massive rotator cuff tear using a CNS for 3 months,the continuous translational tendon-to-bone interface was fully regenerated,and fatty infiltration was simultaneously inhibited.Instead of micro-CT,μCT was employed to visualize the integrity and intricateness of the three-dimensional microstructure of the CNS-induced-healed tendon-to-bone interface at an ultra-high resolution of less than 1μm.This study sheds light on the correlation between nanofiber post treatment and massive rotator cuff repair and provides a general strategy for crimped nanofiber preparation and tendon-to-bone interface imaging characterization.
基金supported by a grant of the Romanian Ministry of Education and Research,CNCS-UEFISCDI,project number PN-III-P4-ID-PCE-2020-2591,within PNCDI III。
文摘Magnesium and its alloys are one of the most used materials for bone implants and tissue engineering.They are characterized by numerous advantages such as biodegradability,high biocompatibility and mechanical properties with values close to the human bone.Unfortunately,the implant surface must be adequately tuned,or Mg-based alloys must be alloyed with other chemical elements due to their increased corrosion effect in physiological media.This article reviews the clinical challenges related to bone repair and regeneration,classifying bone defects and presenting some of the most used and modern therapies for bone injuries,such as Ilizarov or Masquelet techniques or stem cell treatments.The implant interface challenges are related to new bone formation and fracture healing,implant degradation and hydrogen release.A detailed analysis of mechanical properties during implant degradation is extensively described based on different literature studies that included in vitro and in vivo tests correlated with material properties’characterization.Mg-based trauma implants such as plates and screws,intramedullary nails,Herbert screws,spine cages,rings for joint treatment and regenerative scaffolds are presented,taking into consideration their manufacturing technology,the implant geometrical dimensions and shape,the type of in vivo or in vitro studies and fracture localization.Modern technologies that modify or adapt the Mg-based implant interfaces are described by presenting the main surface microstructural modifications,physical deposition and chemical conversion coatings.The last part of the article provides some recommendations from a translational perspective,identifies the challenges associated with Mg-based implants and presents some future opportunities.This review outlines the available literature on trauma and regenerative bone implants and describes the main techniques used to control the alloy corrosion rate and the cellular environment of the implant.
