Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human...Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor tissueregeneration.Thus,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic lineage.In this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based deposition.The inclusion of the nanofiller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon printing.The composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)model.The inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven days.This study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.展开更多
Bone morphogenetic protein 2(BMP2)is clinically applied for treating intractable fractures and promoting spinal fusion because of its osteogenic potency.However,adverse effects following the release of supraphysiologi...Bone morphogenetic protein 2(BMP2)is clinically applied for treating intractable fractures and promoting spinal fusion because of its osteogenic potency.However,adverse effects following the release of supraphysiological doses of BMP2 from collagen carriers are widely reported.Nanoclay gel(NC)is attracting attention as a biomaterial,given the potential for localized efficacy of administered agents.However,the efficacy and mech-anism of action of NC/BMP2 remain unclear.This study explored the efficacy of NC as a BMP2 carrier in bone regeneration and the enhancement mechanism.Subfascial implantation of NC containing BMP2 elicited superior bone formation compared with collagen sponge(CS).Cartilage was uniformly formed inside the NC,whereas CS formed cartilage only on the perimeter.Additionally,CS induced a dose-dependent inflammatory response around the implantation site,whereas NC induced a minor response,and inflammatory cells were observed inside the NC.In a rat spinal fusion model,NC promoted high-quality bony fusion compared to CS.In vitro,NC enhanced chondrogenic and osteogenic differentiation of hBMSCs and ATDC5 cells while inhibiting osteoclas-togenesis.Overall,NC/BMP2 facilitates spatially controlled,high-quality endochondral bone formation without BMP2-induced inflammation and promotes high-density new bone,functioning as a next-generation BMP2 carrier.展开更多
Bone tissue engineering requires a combination of materials,cells,growth factors and mechanical cues to recapitulate bone formation.In this study we evaluated hybrid hydrogels for minimally invasive bone formation by ...Bone tissue engineering requires a combination of materials,cells,growth factors and mechanical cues to recapitulate bone formation.In this study we evaluated hybrid hydrogels for minimally invasive bone formation by combining biomaterials with skeletal stem cells and staged release of growth factors together with mechanotransduction.Hybrid hydrogels consisting of alginate and decellularized,demineralised bone extracellular matrix(ALG/ECM)were seeded with Stro-1t human bone marrow stromal cells(HBMSCs).Dual combinations of growth factors within staged-release polylactic-co-glycolic acid(PLGA)microparticles were added to hydrogels to mimic,in part,the signalling events in bone regeneration:VEGF,TGF-β_(3),PTHrP(fast release),or BMP-2,vitamin D_(3)(slow release).Mechanotransduction was initiated using magnetic fields to remotely actuate superparamagnetic nanoparticles(MNP)targeted to TREK1 ion channels.Hybrid hydrogels were implanted subcutaneously within mice for 28 days,and evaluated for bone formation using micro-CT and histology.Control hydrogels lacking HBMSCs,growth factors,or MNP became mineralised,and neither growth factors,HBMSCs,nor mechanotransduction increased bone formation.However,structural differences in the newly-formed bone were influenced by growth factors.Slow release of BMP-2 induced thick bone trabeculae and PTHrP or VitD_(3)increased bone formation.However,fast-release of TGF-β_(3)and VEGF resulted in thin trabeculae.Mechanotransduction reversed the trabecular thinning and increased collagen deposition with PTHrP and VitD_(3).Our findings demonstrate the potential of hybrid ALG/ECM hydrogel–cell–growth factor constructs to repair bone in combination with mechanotransduction for fine-tuning bone structure.This approach may form a minimally invasive reparative strategy for bone tissue engineering applications.展开更多
基金supported by grants from the Biotechnology and Biological Sciences Research Council(Nos.BBSRC LO21071/and BB/L00609X/1)UK Regenerative Medicine Platform Hub Acellular Approaches for Therapeutic Delivery(No.MR/K026682/1)+3 种基金Acellular Hub,SMART Materials 3D Architecture(No.MR/R015651/1)the UK Regenerative Medicine Platform(No.MR/L012626/1 Southampton Imaging)to ROCOMRCAMED Regenerative Medicine and Stem Cell Research Initiative(No.MR/V00543X/1)to JID,ROCO and YHKGC acknowledges funding from AIRC Aldi Fellowship under grant agreement No.25412.
文摘Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor tissueregeneration.Thus,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic lineage.In this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based deposition.The inclusion of the nanofiller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon printing.The composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)model.The inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven days.This study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.
基金financially supported by the JSPS Grant-in-Aid C(20K09479)to TKresearch grant(J210701148)by Biosciencepartners Inc.
文摘Bone morphogenetic protein 2(BMP2)is clinically applied for treating intractable fractures and promoting spinal fusion because of its osteogenic potency.However,adverse effects following the release of supraphysiological doses of BMP2 from collagen carriers are widely reported.Nanoclay gel(NC)is attracting attention as a biomaterial,given the potential for localized efficacy of administered agents.However,the efficacy and mech-anism of action of NC/BMP2 remain unclear.This study explored the efficacy of NC as a BMP2 carrier in bone regeneration and the enhancement mechanism.Subfascial implantation of NC containing BMP2 elicited superior bone formation compared with collagen sponge(CS).Cartilage was uniformly formed inside the NC,whereas CS formed cartilage only on the perimeter.Additionally,CS induced a dose-dependent inflammatory response around the implantation site,whereas NC induced a minor response,and inflammatory cells were observed inside the NC.In a rat spinal fusion model,NC promoted high-quality bony fusion compared to CS.In vitro,NC enhanced chondrogenic and osteogenic differentiation of hBMSCs and ATDC5 cells while inhibiting osteoclas-togenesis.Overall,NC/BMP2 facilitates spatially controlled,high-quality endochondral bone formation without BMP2-induced inflammation and promotes high-density new bone,functioning as a next-generation BMP2 carrier.
基金supported by the BBSRC(sLOLA grant BB/G010579/1)an EU ERC Advanced Grant DYNACEUTICS(grant no.789119).
文摘Bone tissue engineering requires a combination of materials,cells,growth factors and mechanical cues to recapitulate bone formation.In this study we evaluated hybrid hydrogels for minimally invasive bone formation by combining biomaterials with skeletal stem cells and staged release of growth factors together with mechanotransduction.Hybrid hydrogels consisting of alginate and decellularized,demineralised bone extracellular matrix(ALG/ECM)were seeded with Stro-1t human bone marrow stromal cells(HBMSCs).Dual combinations of growth factors within staged-release polylactic-co-glycolic acid(PLGA)microparticles were added to hydrogels to mimic,in part,the signalling events in bone regeneration:VEGF,TGF-β_(3),PTHrP(fast release),or BMP-2,vitamin D_(3)(slow release).Mechanotransduction was initiated using magnetic fields to remotely actuate superparamagnetic nanoparticles(MNP)targeted to TREK1 ion channels.Hybrid hydrogels were implanted subcutaneously within mice for 28 days,and evaluated for bone formation using micro-CT and histology.Control hydrogels lacking HBMSCs,growth factors,or MNP became mineralised,and neither growth factors,HBMSCs,nor mechanotransduction increased bone formation.However,structural differences in the newly-formed bone were influenced by growth factors.Slow release of BMP-2 induced thick bone trabeculae and PTHrP or VitD_(3)increased bone formation.However,fast-release of TGF-β_(3)and VEGF resulted in thin trabeculae.Mechanotransduction reversed the trabecular thinning and increased collagen deposition with PTHrP and VitD_(3).Our findings demonstrate the potential of hybrid ALG/ECM hydrogel–cell–growth factor constructs to repair bone in combination with mechanotransduction for fine-tuning bone structure.This approach may form a minimally invasive reparative strategy for bone tissue engineering applications.
