Articular cartilage defect repair is a problem that has long plagued clinicians.Although mesenchymal stem cells(MSCs)have the potential to regenerate articular cartilage,they also have many limitations.Recent studies ...Articular cartilage defect repair is a problem that has long plagued clinicians.Although mesenchymal stem cells(MSCs)have the potential to regenerate articular cartilage,they also have many limitations.Recent studies have found that MSC-derived exosomes(MSC-Exos)play an important role in tissue regeneration.The purpose of this study was to verify whether MSC-Exos can enhance the reparative effect of the acellular cartilage extracellular matrix(ACECM)scaffold and to explore the underlying mechanism.The results of in vitro experiments show that human umbilical cord Wharton’s jelly MSC-Exos(hWJMSC-Exos)can promote the migration and proliferation of bone marrow-derived MSCs(BMSCs)and the proliferation of chondrocytes.We also found that hWJMSC-Exos can promote the polarization of macrophages toward the M2 phenotype.The results of a rabbit knee osteochondral defect repair model confirmed that hWJMSC-Exos can enhance the effect of the ACECM scaffold and promote osteochondral regeneration.We demonstrated that hWJMSC-Exos can regulate the microenvironment of the articular cavity using a rat knee joint osteochondral defect model.This effect was mainly manifested in promoting the polarization of macrophages toward the M2 phenotype and inhibiting the inflammatory response,which may be a promoting factor for osteochondral regeneration.In addition,microRNA(miRNA)sequencing confirmed that hWJMSC-Exos contain many miRNAs that can promote the regeneration of hyaline cartilage.We further clarified the role of hWJMSC-Exos in osteochondral regeneration through target gene prediction and pathway enrichment analysis.In summary,this study confirms that hWJMSC-Exos can enhance the effect of the ACECM scaffold and promote osteochondral regeneration.展开更多
Articular cartilage(AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis(OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying...Articular cartilage(AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis(OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying various therapeutic agents have been developed to improve therapeutic localization and retention, optimize controlled drug release profiles and target different pathological processes. Due to the complex and multifactorial characteristics of cartilage injury pathology and heterogeneity of the cartilage structure deposited within a dense matrix, delivery systems loaded with a single therapeutic agent are hindered from reaching multiple targets in a spatiotemporal matched manner and thus fail to mimic the natural processes of biosynthesis, compromising the goal of full cartilage regeneration. Emerging evidence highlights the importance of sequential delivery strategies targeting multiple pathological processes. In this review, we first summarize the current status and progress achieved in single-drug delivery strategies for the treatment of AC diseases. Subsequently, we focus mainly on advances in multiple drug delivery applications, including sequential release formulations targeting various pathological processes, synergistic targeting of the same pathological process, the spatial distribution in multiple tissues, and heterogeneous regeneration. We hope that this review will inspire the rational design of intraarticular drug delivery systems(DDSs) in the future.展开更多
Tissue engineering provides a promising avenue for treating cartilage defects.However,great challenges remain in the development of structurally and functionally optimized scaffolds for cartilage repair and regenerati...Tissue engineering provides a promising avenue for treating cartilage defects.However,great challenges remain in the development of structurally and functionally optimized scaffolds for cartilage repair and regeneration.In this study,decellularized cartilage extracellular matrix(ECM)and waterborne polyurethane(WPU)were employed to construct WPU and WPU-ECM scaffolds by water-based 3D printing using low-temperature deposition manufacturing(LDM)system,which combines rapid deposition manufacturing with phase separation techniques.The scaffolds successfully achieved hierarchical macro-microporous structures.After adding ECM,WPU scaffolds were markedly optimized in terms of porosity,hydrophilia and bioactive components.Moreover,the optimized WPU-ECM scaffolds were found to be more suitable for cell distribution,adhesion,and proliferation than the WPU scaffolds.Most importantly,the WPU-ECM scaffold could facilitate the production of glycosaminoglycan(GAG)and collagen and the upregulation of cartilage-specific genes.These results indicated that the WPU-ECM scaffold with hierarchical macro-microporous structures could recreate a favorable microenvironment for cell adhesion,proliferation,differentiation,and ECM production.In vivo studies further revealed that the hierarchical macro-microporous WPU-ECM scaffold combined with the microfracture procedure successfully regenerated hyaline cartilage in a rabbit model.Six months after implantation,the repaired cartilage showed a similar histological structure and mechanical performance to that of normal cartilage.In conclusion,the hierarchical macro-microporous WPU-ECM scaffold may be a promising candidate for cartilage tissue engineering applications in the future.展开更多
Due to the sophisticated hierarchical structure and limited reparability of articular cartilage(AC),the ideal regeneration of AC defects has been a major challenge in the field of regenerative medicine.As defects prog...Due to the sophisticated hierarchical structure and limited reparability of articular cartilage(AC),the ideal regeneration of AC defects has been a major challenge in the field of regenerative medicine.As defects progress,they often extend from the cartilage layer to the subchondral bone and ultimately lead to osteoarthritis.Tissue engineering techniques bring new hope for AC regeneration.To meet the regenerative requirements of the heterogeneous and layered structure of native AC tissue,a substantial number of multilayered biomimetic scaffolds have been studied.Ideal multilayered scaffolds should generate zone-specific functional tissue similar to native AC tissue.This review focuses on the current status of multilayered scaffolds developed for AC defect repair,including design strategies based on the degree of defect severity and the zone-specific characteristics of AC tissue,the selection and composition of biomaterials,and techniques for design and manufacturing.The challenges and future perspectives of biomimetic multilayered scaffold strategies for AC regeneration are also discussed.展开更多
Many recent studies have shown that joint-resident mesenchymal stem cells(MSCs)play a vital role in articular cartilage(AC)in situ regeneration.Specifically,synovium-derived MSCs(SMSCs),which have strong chondrogenic ...Many recent studies have shown that joint-resident mesenchymal stem cells(MSCs)play a vital role in articular cartilage(AC)in situ regeneration.Specifically,synovium-derived MSCs(SMSCs),which have strong chondrogenic differentiation potential,may be the main driver of cartilage repair.However,both the insufficient number of MSCs and the lack of an ideal regenerative microenvironment in the defect area will seriously affect the regeneration of AC.Tetrahedral framework nucleic acids(tFNAs),notable novel nanomaterials,are considered prospective biological regulators in biomedical engineering.Here,we aimed to explore whether tFNAs have positive effects on AC in situ regeneration and to investigate the related mechanism.The results of in vitro experiments showed that the proliferation and migration of SMSCs were significantly enhanced by tFNAs.In addition,tFNAs,which were added to chondrogenic induction medium,were shown to promote the chondrogenic capacity of SMSCs by increasing the phosphorylation of Smad2/3.In animal models,the injection of tFNAs improved the therapeutic outcome of cartilage defects compared with that of the control treatments without tFNAs.In conclusion,this is the first report to demonstrate that tFNAs can promote the chondrogenic differentiation of SMSCs in vitro and enhance AC regeneration in vivo,indicating that tFNAs may become a promising therapeutic for AC regeneration.展开更多
Despite intensive effort was made to regenerate injured meniscus by cell-free strategies through recruiting endogenous stem/progenitor cells,meniscus regeneration remains a great challenge in clinic.In this study,we f...Despite intensive effort was made to regenerate injured meniscus by cell-free strategies through recruiting endogenous stem/progenitor cells,meniscus regeneration remains a great challenge in clinic.In this study,we found decellularized meniscal extracellular matrix(MECM)preserved native meniscal collagen and glycosaminoglycans which could be a good endogenous regeneration guider for stem cells.Moreover,MECM significantly promoted meniscal fibrochondrocytes viability and proliferation,increased the expression of type II collagen and proteoglycans in vitro.Meanwhile,we designed 3D-printed polycaprolactone(PCL)scaffolds which mimic the circumferential and radial collagen orientation in native meniscus.Taken these two advantages together,a micro-structure and micro-environment dually biomimetic cell-free scaffold was manipulated.This cell-free PCL-MECM scaffold displayed superior biocompatibility and yielded favorable biomechanical capacities closely to native meniscus.Strikingly,neo-menisci were regenerated within PCL-MECM scaffolds which were transplanted into knee joints underwent medial meniscectomy in rabbits and sheep models.Histological staining confirmed neo-menisci showed meniscus-like heterogeneous staining.Mankin scores showed PCL-MECM scaffold could protect articular cartilage well,and knee X-ray examination revealed same results.Knee magnetic resonance imaging(MRI)scanning also showed some neo-menisci in PCL-MECM scaffold group.In conclusion,PCL-MECM scaffold appears to optimize meniscus regeneration.This could represent a promising approach worthy of further investigation in preclinical applications.展开更多
Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the de...Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix(DCM)scaffold effectively promoted the regeneration of osteochondral defects.Overall,new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study.Moreover,we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix(DCM)scaffold effectively promoted the regeneration of osteochondral defects.Overall,new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study.Moreover,we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.展开更多
Articular cartilage injury(ACI)remains one of the key challenges in regenerative medicine,as current treatment strategies do not result in ideal regeneration of hyaline-like cartilage.Enhancing endogenous repair via m...Articular cartilage injury(ACI)remains one of the key challenges in regenerative medicine,as current treatment strategies do not result in ideal regeneration of hyaline-like cartilage.Enhancing endogenous repair via micro-RNAs(miRNAs)shows promise as a regenerative therapy.miRNA-140 and miRNA-455 are two key and promising candidates for regulating the chondrogenic differentiation of mesenchymal stem cells(MSCs).In this study,we innovatively synthesized a multifunctional tetrahedral framework in which a nucleic acid(tFNA)-based targeting miRNA codelivery system,named A-T-M,was used.With tFNAs as vehicles,miR-140 and miR-455 were connected to and modified on tFNAs,while Apt19S(a DNA aptamer targeting MSCs)was directly integrated into the nanocomplex.The relevant results showed that A-T-M efficiently delivered miR-140 and miR-455 into MSCs and subsequently regulated MSC chondrogenic differentiation through corresponding mechanisms.Interestingly,a synergistic effect between miR-140 and miR-455 was revealed.Furthermore,A-T-M successfully enhanced the endogenous repair capacity of articular cartilage in vivo and effectively inhibited hypertrophic chondrocyte formation.A-T-M provides a new perspective and strategy for the regeneration of articular cartilage,showing strong clinical application value in the future treatment of ACI.展开更多
The field of regenerative medicine faces a notable challenge in terms of the regeneration of articular cartilage.Without proper treatment,it can lead to osteoarthritis.Based on the research findings,human umbilical co...The field of regenerative medicine faces a notable challenge in terms of the regeneration of articular cartilage.Without proper treatment,it can lead to osteoarthritis.Based on the research findings,human umbilical cord mesenchymal stem cells(hUMSCs)are considered an excellent choice for regenerating cartilage.However,there is still a lack of suitable biomaterials to control their ability to self-renew and differentiate.To address this issue,in this study using tetrahedral framework nucleic acids(tFNAs)as a new method in an in vitro culture setting to manage the behaviour of hUMSCs was proposed.Then,the influence of tFNAs on hUMSC proliferation,migration and chondrogenic differentiation was explored by combining bioinformatics methods.In addition,a variety of molecular biology techniques have been used to investigate deep molecular mechanisms.Relevant results demonstrated that tFNAs can affect the transcriptome and multiple signalling pathways of hUMSCs,among which the PI3K/Akt pathway is significantly activated.Furthermore,tFNAs can regulate the expression levels of multiple proteins(GSK3β,RhoA and mTOR)downstream of the PI3K-Akt axis to further enhance cell proliferation,migration and hUMSC chondrogenic differentiation.tFNAs provide new insight into enhancing the chondrogenic potential of hUMSCs,which exhibits promising potential for future utilization within the domains of AC regeneration and clinical treatment.展开更多
基金This work was supported by the National Key R&D Program of China(2019 YFA 0110600)the National Natural Science Foundation of China(81772319)+1 种基金the Scientific Research Funding Project of Education Department of Liaoning Province(JC2019001)the China Postdoctoral Science Foundation(2020M681010).
文摘Articular cartilage defect repair is a problem that has long plagued clinicians.Although mesenchymal stem cells(MSCs)have the potential to regenerate articular cartilage,they also have many limitations.Recent studies have found that MSC-derived exosomes(MSC-Exos)play an important role in tissue regeneration.The purpose of this study was to verify whether MSC-Exos can enhance the reparative effect of the acellular cartilage extracellular matrix(ACECM)scaffold and to explore the underlying mechanism.The results of in vitro experiments show that human umbilical cord Wharton’s jelly MSC-Exos(hWJMSC-Exos)can promote the migration and proliferation of bone marrow-derived MSCs(BMSCs)and the proliferation of chondrocytes.We also found that hWJMSC-Exos can promote the polarization of macrophages toward the M2 phenotype.The results of a rabbit knee osteochondral defect repair model confirmed that hWJMSC-Exos can enhance the effect of the ACECM scaffold and promote osteochondral regeneration.We demonstrated that hWJMSC-Exos can regulate the microenvironment of the articular cavity using a rat knee joint osteochondral defect model.This effect was mainly manifested in promoting the polarization of macrophages toward the M2 phenotype and inhibiting the inflammatory response,which may be a promoting factor for osteochondral regeneration.In addition,microRNA(miRNA)sequencing confirmed that hWJMSC-Exos contain many miRNAs that can promote the regeneration of hyaline cartilage.We further clarified the role of hWJMSC-Exos in osteochondral regeneration through target gene prediction and pathway enrichment analysis.In summary,this study confirms that hWJMSC-Exos can enhance the effect of the ACECM scaffold and promote osteochondral regeneration.
基金supported by the National Key R&D Program of China (2019YFA0110600, China)Medical Research and Development Projects (BLB20J001, China)。
文摘Articular cartilage(AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis(OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying various therapeutic agents have been developed to improve therapeutic localization and retention, optimize controlled drug release profiles and target different pathological processes. Due to the complex and multifactorial characteristics of cartilage injury pathology and heterogeneity of the cartilage structure deposited within a dense matrix, delivery systems loaded with a single therapeutic agent are hindered from reaching multiple targets in a spatiotemporal matched manner and thus fail to mimic the natural processes of biosynthesis, compromising the goal of full cartilage regeneration. Emerging evidence highlights the importance of sequential delivery strategies targeting multiple pathological processes. In this review, we first summarize the current status and progress achieved in single-drug delivery strategies for the treatment of AC diseases. Subsequently, we focus mainly on advances in multiple drug delivery applications, including sequential release formulations targeting various pathological processes, synergistic targeting of the same pathological process, the spatial distribution in multiple tissues, and heterogeneous regeneration. We hope that this review will inspire the rational design of intraarticular drug delivery systems(DDSs) in the future.
基金This work was supported by the National Key R&D Program of China(2018YFC1105900)the National Natural Science Foundation of China(81772319)+2 种基金the Natural Science Foundation of Beijing Municipality(7204270)the Beijing JST Research Funding(ZR-201908)the Innovation Fund for Outstanding Doctoral Candidates of Peking University Health Science Center(71013Y2029).
文摘Tissue engineering provides a promising avenue for treating cartilage defects.However,great challenges remain in the development of structurally and functionally optimized scaffolds for cartilage repair and regeneration.In this study,decellularized cartilage extracellular matrix(ECM)and waterborne polyurethane(WPU)were employed to construct WPU and WPU-ECM scaffolds by water-based 3D printing using low-temperature deposition manufacturing(LDM)system,which combines rapid deposition manufacturing with phase separation techniques.The scaffolds successfully achieved hierarchical macro-microporous structures.After adding ECM,WPU scaffolds were markedly optimized in terms of porosity,hydrophilia and bioactive components.Moreover,the optimized WPU-ECM scaffolds were found to be more suitable for cell distribution,adhesion,and proliferation than the WPU scaffolds.Most importantly,the WPU-ECM scaffold could facilitate the production of glycosaminoglycan(GAG)and collagen and the upregulation of cartilage-specific genes.These results indicated that the WPU-ECM scaffold with hierarchical macro-microporous structures could recreate a favorable microenvironment for cell adhesion,proliferation,differentiation,and ECM production.In vivo studies further revealed that the hierarchical macro-microporous WPU-ECM scaffold combined with the microfracture procedure successfully regenerated hyaline cartilage in a rabbit model.Six months after implantation,the repaired cartilage showed a similar histological structure and mechanical performance to that of normal cartilage.In conclusion,the hierarchical macro-microporous WPU-ECM scaffold may be a promising candidate for cartilage tissue engineering applications in the future.
基金supported by the National Key Research and Development Program of China(No.2019YFA0110600)the National Natural Science Foundation of China(No.81772319).
文摘Due to the sophisticated hierarchical structure and limited reparability of articular cartilage(AC),the ideal regeneration of AC defects has been a major challenge in the field of regenerative medicine.As defects progress,they often extend from the cartilage layer to the subchondral bone and ultimately lead to osteoarthritis.Tissue engineering techniques bring new hope for AC regeneration.To meet the regenerative requirements of the heterogeneous and layered structure of native AC tissue,a substantial number of multilayered biomimetic scaffolds have been studied.Ideal multilayered scaffolds should generate zone-specific functional tissue similar to native AC tissue.This review focuses on the current status of multilayered scaffolds developed for AC defect repair,including design strategies based on the degree of defect severity and the zone-specific characteristics of AC tissue,the selection and composition of biomaterials,and techniques for design and manufacturing.The challenges and future perspectives of biomimetic multilayered scaffold strategies for AC regeneration are also discussed.
基金This study was supported by the National Key R&D Program of China(2019YFA0110600).
文摘Many recent studies have shown that joint-resident mesenchymal stem cells(MSCs)play a vital role in articular cartilage(AC)in situ regeneration.Specifically,synovium-derived MSCs(SMSCs),which have strong chondrogenic differentiation potential,may be the main driver of cartilage repair.However,both the insufficient number of MSCs and the lack of an ideal regenerative microenvironment in the defect area will seriously affect the regeneration of AC.Tetrahedral framework nucleic acids(tFNAs),notable novel nanomaterials,are considered prospective biological regulators in biomedical engineering.Here,we aimed to explore whether tFNAs have positive effects on AC in situ regeneration and to investigate the related mechanism.The results of in vitro experiments showed that the proliferation and migration of SMSCs were significantly enhanced by tFNAs.In addition,tFNAs,which were added to chondrogenic induction medium,were shown to promote the chondrogenic capacity of SMSCs by increasing the phosphorylation of Smad2/3.In animal models,the injection of tFNAs improved the therapeutic outcome of cartilage defects compared with that of the control treatments without tFNAs.In conclusion,this is the first report to demonstrate that tFNAs can promote the chondrogenic differentiation of SMSCs in vitro and enhance AC regeneration in vivo,indicating that tFNAs may become a promising therapeutic for AC regeneration.
基金This work was supported by the National Key R&D Program of China[2019YFA0110600]the National Natural Science Foundation of China[81972070,81201212]+1 种基金the China Postdoctoral Science Foundation Grant[2019TQ0379,2019M663262]PLA Youth Project for Medical Science(18QNP057).
文摘Despite intensive effort was made to regenerate injured meniscus by cell-free strategies through recruiting endogenous stem/progenitor cells,meniscus regeneration remains a great challenge in clinic.In this study,we found decellularized meniscal extracellular matrix(MECM)preserved native meniscal collagen and glycosaminoglycans which could be a good endogenous regeneration guider for stem cells.Moreover,MECM significantly promoted meniscal fibrochondrocytes viability and proliferation,increased the expression of type II collagen and proteoglycans in vitro.Meanwhile,we designed 3D-printed polycaprolactone(PCL)scaffolds which mimic the circumferential and radial collagen orientation in native meniscus.Taken these two advantages together,a micro-structure and micro-environment dually biomimetic cell-free scaffold was manipulated.This cell-free PCL-MECM scaffold displayed superior biocompatibility and yielded favorable biomechanical capacities closely to native meniscus.Strikingly,neo-menisci were regenerated within PCL-MECM scaffolds which were transplanted into knee joints underwent medial meniscectomy in rabbits and sheep models.Histological staining confirmed neo-menisci showed meniscus-like heterogeneous staining.Mankin scores showed PCL-MECM scaffold could protect articular cartilage well,and knee X-ray examination revealed same results.Knee magnetic resonance imaging(MRI)scanning also showed some neo-menisci in PCL-MECM scaffold group.In conclusion,PCL-MECM scaffold appears to optimize meniscus regeneration.This could represent a promising approach worthy of further investigation in preclinical applications.
基金Natural Science Foundation of Beijing Municipality(L234024)National Natural Science Foundation of China(82102552)Natural Science Foundation of Guangdong Province(2024A1515030295).
文摘Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix(DCM)scaffold effectively promoted the regeneration of osteochondral defects.Overall,new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study.Moreover,we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.Utilizing transplanted human umbilical cord mesenchymal stem cells(HUMSCs)for cartilage defects yielded advanced tissue regeneration,but the underlying mechanism remain elucidated.Early after HUMSCs delivery to the defects,we observed substantial apoptosis.The released apoptotic vesicles(apoVs)of HUMSCs promoted cartilage regeneration by alleviating the chondro-immune microenvironment.ApoVs triggered M2 polarization in macrophages while simultaneously facilitating the chondrogenic differentiation of endogenous MSCs.Mechanistically,in macrophages,miR-100-5p delivered by apoVs activated the MAPK/ERK signaling pathway to promote M2 polarization.In MSCs,let-7i-5p delivered by apoVs promoted chondrogenic differentiation by targeting the eEF2K/p38 MAPK axis.Consequently,a cell-free cartilage regeneration strategy using apoVs combined with a decellularized cartilage extracellular matrix(DCM)scaffold effectively promoted the regeneration of osteochondral defects.Overall,new mechanisms of cartilage regeneration by transplanted MSCs were unconcealed in this study.Moreover,we provided a novel experimental basis for cell-free tissue engineering-based cartilage regeneration utilizing apoVs.
基金supported by the Natural Science Foundation of Beijing Municipality(L234024)。
文摘Articular cartilage injury(ACI)remains one of the key challenges in regenerative medicine,as current treatment strategies do not result in ideal regeneration of hyaline-like cartilage.Enhancing endogenous repair via micro-RNAs(miRNAs)shows promise as a regenerative therapy.miRNA-140 and miRNA-455 are two key and promising candidates for regulating the chondrogenic differentiation of mesenchymal stem cells(MSCs).In this study,we innovatively synthesized a multifunctional tetrahedral framework in which a nucleic acid(tFNA)-based targeting miRNA codelivery system,named A-T-M,was used.With tFNAs as vehicles,miR-140 and miR-455 were connected to and modified on tFNAs,while Apt19S(a DNA aptamer targeting MSCs)was directly integrated into the nanocomplex.The relevant results showed that A-T-M efficiently delivered miR-140 and miR-455 into MSCs and subsequently regulated MSC chondrogenic differentiation through corresponding mechanisms.Interestingly,a synergistic effect between miR-140 and miR-455 was revealed.Furthermore,A-T-M successfully enhanced the endogenous repair capacity of articular cartilage in vivo and effectively inhibited hypertrophic chondrocyte formation.A-T-M provides a new perspective and strategy for the regeneration of articular cartilage,showing strong clinical application value in the future treatment of ACI.
基金supported by the National Key R&D Program of China(2019YFA0110600).
文摘The field of regenerative medicine faces a notable challenge in terms of the regeneration of articular cartilage.Without proper treatment,it can lead to osteoarthritis.Based on the research findings,human umbilical cord mesenchymal stem cells(hUMSCs)are considered an excellent choice for regenerating cartilage.However,there is still a lack of suitable biomaterials to control their ability to self-renew and differentiate.To address this issue,in this study using tetrahedral framework nucleic acids(tFNAs)as a new method in an in vitro culture setting to manage the behaviour of hUMSCs was proposed.Then,the influence of tFNAs on hUMSC proliferation,migration and chondrogenic differentiation was explored by combining bioinformatics methods.In addition,a variety of molecular biology techniques have been used to investigate deep molecular mechanisms.Relevant results demonstrated that tFNAs can affect the transcriptome and multiple signalling pathways of hUMSCs,among which the PI3K/Akt pathway is significantly activated.Furthermore,tFNAs can regulate the expression levels of multiple proteins(GSK3β,RhoA and mTOR)downstream of the PI3K-Akt axis to further enhance cell proliferation,migration and hUMSC chondrogenic differentiation.tFNAs provide new insight into enhancing the chondrogenic potential of hUMSCs,which exhibits promising potential for future utilization within the domains of AC regeneration and clinical treatment.
