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
The interfacial oxidation behavior of Cr_(4)Mo_(4) V high-speed steel(HSS)joints undergoing hot-compression bonding was investigated by using optical microscopy(OM),scanning electron microscopy(SEM),and transmission e...The interfacial oxidation behavior of Cr_(4)Mo_(4) V high-speed steel(HSS)joints undergoing hot-compression bonding was investigated by using optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).In the heating and holding processes,dispersed rod-like and granularδ-Al_(2)O_(3) oxides were formed at the interface and in the matrix near the interface due to the selective oxidation and internal oxidation of Al,while irregular Si-Al-O compounds and spheroidal SiO_(2) particles were formed at the interface.After the post-holding treatment,SiO_(2) oxides and Si-Al-O compounds were dissolved into the matrix,andδ-Al_(2)O_(3) oxides were transformed into nanoscaleα-Al_(2)O_(3) particles,which did not deteriorate the mechanical properties of the joints.The formation and migration of newly-formed grain boundaries by plastic deformation and post-holding treatment were the main mechanism for interface healing.The tensile test results showed that the strength of the healed joints was comparable to that of the base material,and the in-situ tensile observations proved that the fracture was initiated at the grain boundary of the matrix rather than at the interface.The clarification of interfacial oxides and microstructure is essential for the application of hot-compression bonding of HSSs.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
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financially supported by the National Key Research and Development Program(No.2018YFA0702900)the National Natural Science Foundation of China(Nos.51774265 and 51701225)+3 种基金the National Science and Technology Major Project of China(Nos.2019ZX06004010 and 2017-VII008-0101)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC04000000)the LingChuang Research Project of China National Nuclear Corporation Program of CAS Interdisciplinary Innovation TeamYouth Innovation Promotion Association,CAS。
文摘The interfacial oxidation behavior of Cr_(4)Mo_(4) V high-speed steel(HSS)joints undergoing hot-compression bonding was investigated by using optical microscopy(OM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).In the heating and holding processes,dispersed rod-like and granularδ-Al_(2)O_(3) oxides were formed at the interface and in the matrix near the interface due to the selective oxidation and internal oxidation of Al,while irregular Si-Al-O compounds and spheroidal SiO_(2) particles were formed at the interface.After the post-holding treatment,SiO_(2) oxides and Si-Al-O compounds were dissolved into the matrix,andδ-Al_(2)O_(3) oxides were transformed into nanoscaleα-Al_(2)O_(3) particles,which did not deteriorate the mechanical properties of the joints.The formation and migration of newly-formed grain boundaries by plastic deformation and post-holding treatment were the main mechanism for interface healing.The tensile test results showed that the strength of the healed joints was comparable to that of the base material,and the in-situ tensile observations proved that the fracture was initiated at the grain boundary of the matrix rather than at the interface.The clarification of interfacial oxides and microstructure is essential for the application of hot-compression bonding of HSSs.
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.
