Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successfulanterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel...Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successfulanterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel. En-hancement of graft healing to bone is important to facilitate early aggressive rehabilitation and a rapid return topre-injury activity levels. No convenient, effective or inexpensive procedures exist to enhance tendon-bone (T-B)healing after surgery. Low-intensity pulsed ultrasound (LIPUS) improves local blood perfusion and angiogenesis,stimulates cartilage maturation, enhances differentiation and proliferation of osteoblasts, and motivates osteogenic differentiation of mesenchymal stem cells (MSCs), and therefore, appears to be a potential non-invasive tool for T-Bhealing in early stage of rehabilitation of ACL reconstruction. It is conceivable that LIPUS could be used to stimulateT-B tunnel healing in the home, with the aim of accelerating rehabilitation and an earlier return to normal activities inthe near future. The purpose of this review is to demonstrate how LIPUS stimulates T-B healing at the cellular andmolecular levels, describe studies in animal models, and provide a future direction for research.展开更多
For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope （SEM）, histological sections and MicroCT were used to observe, measure ...For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope （SEM）, histological sections and MicroCT were used to observe, measure and model the micro- structure of cartilage/bone interface. The results showed that the cartilage/bone interface is in a hierarchical structure which is composed of four different tissue layers. The interlocking of hyaline cartilage and calcified cartilage and that of calcified car- tilage and subchondral bone are in the manner of＂protrusion-pore＂ with average diameter of 17.0 gm and 34.1 lam respectively. In addition, the cancellous bone under the cartilage is also formed by four layer hierarchical structure, and the adjacent layers are connected by bone trabecula in the shape of H, I and Y, forming a complex interwoven network structure. Finally, the simplified structure model of the cartilage/bone interface was proposed according to the natural articular cartilage/bone interface. The simplified model is a 4-layer gradient biomimetic structure, which corresponds to four different tissues of natural cartilage/bone interface. The results of this work would be beneficial to the design of bionic scaffold for the tissue engineering of articular cartilage/bone.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
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
The treatment of rotator cuff tear is one of the major challenges for orthopedic surgeons.The key to treatment is the reconstruction of the tendon-bone interface(TBI).Autologous platelet-rich plasma(PRP)is used as a t...The treatment of rotator cuff tear is one of the major challenges for orthopedic surgeons.The key to treatment is the reconstruction of the tendon-bone interface(TBI).Autologous platelet-rich plasma(PRP)is used as a therapeutic agent to accelerate the healing of tendons,as it contains a variety of growth factors and is easy to prepare.Graphene oxide(GO)is known to improve the physical properties of biomaterials and promote tissue repair.In this study,PRP gels containing various concentrations of GO were prepared to promote TBI healing and supraspinatus tendon reconstruction in a rabbit model.The incorporation of GO improved the ultrastructure and mechanical properties of the PRP gels.The gels containing 0.5 mg/ml GO(0.5 GO/PRP)continuously released transforming growth factor-b1(TGF-b1)and platelet-derived growth factor(PDGF)-AB,and the released TGF-b1 and PDGF-AB were still at high concentrations,1063.451 pg/ml and814.217 pg/ml,respectively,on the 14th day.In vitro assays showed that the 0.5 GO/PRP gels had good biocompatibility and promoted bone marrow mesenchymal stem cells proliferation and osteogenic and chondrogenic differentiation.After 12 weeks of implantation,the magnetic resonance imaging,microcomputed tomography and histological results indicated that the newly regenerated tendons in the 0.5 GO/PRP group had a similar structure to natural tendons.Moreover,the biomechanical results showed that the newly formed tendons in the 0.5 GO/PRP group had better biomechanical properties compared to those in the other groups,and had more stable TBI tissue.Therefore,the combination of PRP and GO has the potential to be a powerful advancement in the treatment of rotator cuff injuries.展开更多
In osteoporosis scenario, tissue response to implants is greatly impaired by the deteriorated boneregeneration microenvironment. In the present study, a Mg-containing akermanite (Ak) ceramic wasemployed for the treatm...In osteoporosis scenario, tissue response to implants is greatly impaired by the deteriorated boneregeneration microenvironment. In the present study, a Mg-containing akermanite (Ak) ceramic wasemployed for the treatment of osteoporotic bone defect, based on the hypothesis that both beneficialions (e.g. Mg^2+ ect.) released by the implants and the weak alkaline microenvironment pH (μe-pH) itcreated may play distinct roles in recovering the abnormal bone regeneration by stimulating osteoblasticanabolic effects. The performance of Ak, b-tricalcium phosphate (β-TCP) and Hardystone (Har) in healinga 3 mm bone defect on the ovariectomized (OVX) osteoporotic rat model was evaluated. Our resultsindicated that, there's more new bone formed in Ak group than in β-TCP or Har group at week 9. Theinitial me-pHs of Ak were significantly higher than that of the β-TCP and Blank group, and this weakalkaline condition was maintained till at least 9 weeks post-surgery. Increased osteoblastic activity whichwas indicated by higher osteoid secretion was observed in Ak group at week 4 to week 9. An intermediatelayer which was rich in phosphorus minerals and bound directly to the new forming bone wasdeveloped on the surface of Ak. In a summary, our study demonstrates that Ak exhibits a superior boneregenerative performance under osteoporosis condition, and might be a promising candidate for thetreatment of osteoporotic bone defect and fracture.展开更多
A biomimetic hip joint simulator that can be used to evaluate the outcome of the cemented total hip replacement has been designed, manufactured and evaluated. The simulator produces motion in the extension/flexion pla...A biomimetic hip joint simulator that can be used to evaluate the outcome of the cemented total hip replacement has been designed, manufactured and evaluated. The simulator produces motion in the extension/flexion plane, with a socket to rotate internal/externally. At the same time a dynamic loading cycle is applied. A validation test was performed on a cemented femoral stem within a novel composite femur. The hone quality has a strong effect on the stem migration and on the integrity of the interfaces. The migration of the stem is a combination of 3-D translation and rotation of the stem. Under the same loading conditions, weak bone allows more stem migration than strong bone. There is a great decrease in the strength of the stem-cement interface after the dynamic test, and the weak bone composite exhibited a greater reduction in interfacial strength than the strong bone composite. The decrease of the interfacial strength indicates that the primary bonding between the stem and the cement mantle had deteriorated and the integrity of stem-cement interface was damaged. The study demonstrates the value of using a hip joint simulator to investigate stem migration and interface integrity within the cemented hip replacement, suggesting that method can be used for in vitro evaluation of the biomaterials used in the cemented hip replacements.展开更多
基金Project (No. 81171687/H0604) supported by the National Natural Science Foundation of China
文摘Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successfulanterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel. En-hancement of graft healing to bone is important to facilitate early aggressive rehabilitation and a rapid return topre-injury activity levels. No convenient, effective or inexpensive procedures exist to enhance tendon-bone (T-B)healing after surgery. Low-intensity pulsed ultrasound (LIPUS) improves local blood perfusion and angiogenesis,stimulates cartilage maturation, enhances differentiation and proliferation of osteoblasts, and motivates osteogenic differentiation of mesenchymal stem cells (MSCs), and therefore, appears to be a potential non-invasive tool for T-Bhealing in early stage of rehabilitation of ACL reconstruction. It is conceivable that LIPUS could be used to stimulateT-B tunnel healing in the home, with the aim of accelerating rehabilitation and an earlier return to normal activities inthe near future. The purpose of this review is to demonstrate how LIPUS stimulates T-B healing at the cellular andmolecular levels, describe studies in animal models, and provide a future direction for research.
基金This paper was supported by the National Natural Science Foundation of China （Grant No： 50875201） and the National Hi-Tech Program of China （Grant No： 2009AA043801）. The authors thank Professor Yiping Tang from Xi＇an Jiaotong University for improving the manuscript.
文摘For improving the theory of gradient microstructure of cartilage/bone interface, human distal femurs were studied. Scanning Electron Microscope （SEM）, histological sections and MicroCT were used to observe, measure and model the micro- structure of cartilage/bone interface. The results showed that the cartilage/bone interface is in a hierarchical structure which is composed of four different tissue layers. The interlocking of hyaline cartilage and calcified cartilage and that of calcified car- tilage and subchondral bone are in the manner of＂protrusion-pore＂ with average diameter of 17.0 gm and 34.1 lam respectively. In addition, the cancellous bone under the cartilage is also formed by four layer hierarchical structure, and the adjacent layers are connected by bone trabecula in the shape of H, I and Y, forming a complex interwoven network structure. Finally, the simplified structure model of the cartilage/bone interface was proposed according to the natural articular cartilage/bone interface. The simplified model is a 4-layer gradient biomimetic structure, which corresponds to four different tissues of natural cartilage/bone interface. The results of this work would be beneficial to the design of bionic scaffold for the tissue engineering of articular cartilage/bone.
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.
基金supported by the Luzhou Municipal People’s Government-SouthwestMedical University Science and Technology Cooperation Achievements Transformation Project(2019LZXNYDJ20C01).
文摘The treatment of rotator cuff tear is one of the major challenges for orthopedic surgeons.The key to treatment is the reconstruction of the tendon-bone interface(TBI).Autologous platelet-rich plasma(PRP)is used as a therapeutic agent to accelerate the healing of tendons,as it contains a variety of growth factors and is easy to prepare.Graphene oxide(GO)is known to improve the physical properties of biomaterials and promote tissue repair.In this study,PRP gels containing various concentrations of GO were prepared to promote TBI healing and supraspinatus tendon reconstruction in a rabbit model.The incorporation of GO improved the ultrastructure and mechanical properties of the PRP gels.The gels containing 0.5 mg/ml GO(0.5 GO/PRP)continuously released transforming growth factor-b1(TGF-b1)and platelet-derived growth factor(PDGF)-AB,and the released TGF-b1 and PDGF-AB were still at high concentrations,1063.451 pg/ml and814.217 pg/ml,respectively,on the 14th day.In vitro assays showed that the 0.5 GO/PRP gels had good biocompatibility and promoted bone marrow mesenchymal stem cells proliferation and osteogenic and chondrogenic differentiation.After 12 weeks of implantation,the magnetic resonance imaging,microcomputed tomography and histological results indicated that the newly regenerated tendons in the 0.5 GO/PRP group had a similar structure to natural tendons.Moreover,the biomechanical results showed that the newly formed tendons in the 0.5 GO/PRP group had better biomechanical properties compared to those in the other groups,and had more stable TBI tissue.Therefore,the combination of PRP and GO has the potential to be a powerful advancement in the treatment of rotator cuff injuries.
基金This work was supported by grants from the National Natural Science Foundation of China(No.51272274,81672227,51372170)Shenzhen Peacock Program(No.110811003586331)Shenzhen Science and Technology Research funding(No.CXZZ 20150401152251209,JSGG20151030140325149,JSGG20150331154931068,CXZZ20140417113430716)and partially from Hong Kong General Research Fund.
文摘In osteoporosis scenario, tissue response to implants is greatly impaired by the deteriorated boneregeneration microenvironment. In the present study, a Mg-containing akermanite (Ak) ceramic wasemployed for the treatment of osteoporotic bone defect, based on the hypothesis that both beneficialions (e.g. Mg^2+ ect.) released by the implants and the weak alkaline microenvironment pH (μe-pH) itcreated may play distinct roles in recovering the abnormal bone regeneration by stimulating osteoblasticanabolic effects. The performance of Ak, b-tricalcium phosphate (β-TCP) and Hardystone (Har) in healinga 3 mm bone defect on the ovariectomized (OVX) osteoporotic rat model was evaluated. Our resultsindicated that, there's more new bone formed in Ak group than in β-TCP or Har group at week 9. Theinitial me-pHs of Ak were significantly higher than that of the β-TCP and Blank group, and this weakalkaline condition was maintained till at least 9 weeks post-surgery. Increased osteoblastic activity whichwas indicated by higher osteoid secretion was observed in Ak group at week 4 to week 9. An intermediatelayer which was rich in phosphorus minerals and bound directly to the new forming bone wasdeveloped on the surface of Ak. In a summary, our study demonstrates that Ak exhibits a superior boneregenerative performance under osteoporosis condition, and might be a promising candidate for thetreatment of osteoporotic bone defect and fracture.
文摘A biomimetic hip joint simulator that can be used to evaluate the outcome of the cemented total hip replacement has been designed, manufactured and evaluated. The simulator produces motion in the extension/flexion plane, with a socket to rotate internal/externally. At the same time a dynamic loading cycle is applied. A validation test was performed on a cemented femoral stem within a novel composite femur. The hone quality has a strong effect on the stem migration and on the integrity of the interfaces. The migration of the stem is a combination of 3-D translation and rotation of the stem. Under the same loading conditions, weak bone allows more stem migration than strong bone. There is a great decrease in the strength of the stem-cement interface after the dynamic test, and the weak bone composite exhibited a greater reduction in interfacial strength than the strong bone composite. The decrease of the interfacial strength indicates that the primary bonding between the stem and the cement mantle had deteriorated and the integrity of stem-cement interface was damaged. The study demonstrates the value of using a hip joint simulator to investigate stem migration and interface integrity within the cemented hip replacement, suggesting that method can be used for in vitro evaluation of the biomaterials used in the cemented hip replacements.
