The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human ...The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone.The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration.In this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a control.We then investigated the effect of additions of Y and Mn on alloys'properties.Our results show that Mn and Y can improve not only compression strength but also corrosion resistance.The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in vivo.The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or brain.Furthermore,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.展开更多
The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fraction...The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.展开更多
Transfection efficiency of hydroxyapatite nanoparticles(HAnps)is relative to the particle size,morphology,surface charge,surface modifier and so on.This study prepared HAnps with doped Tb/Mg by hydrothermal synthesis ...Transfection efficiency of hydroxyapatite nanoparticles(HAnps)is relative to the particle size,morphology,surface charge,surface modifier and so on.This study prepared HAnps with doped Tb/Mg by hydrothermal synthesis method(HTSM)and investigated the effects of different Tb/Mg contents on the morphology,particle size,surface charge,composition and cellular endocytosis of HAnps.The results showed that Mg-HAnps possessed better dispersion ability than Tb-HAnps.With increasing doping content of Tb/Mg-HAnps,the granularity of Tb-HAnps increased,while that of Mg-HAnps declined.Both particle size and zeta potential of Mg-HAnps were lower than those of Tb-HAnps.7.5%Mg-doping HAnps presented relatively uniform slender rod morphology with average size of30nm,while10%Mg-doping HAnps were prone to agglomeration.Moreover,Mg-HAnps-GFP(green fluorescent protein)endocytosed by MG63cells was dotted in the perinuclear region,while Tb-HAnps were more likely to aggregate.In conclusion,as gene vectors,Mg-HAnps showed enhanced properties compared to Tb-HAnps.展开更多
The combination between biphasic calcium phosphate(BCP)and the osteomimetic porous microstructure obtained via freeze casting is hoped to achieve excellent bone regeneration,while the effects of HA and b-TCP ratio cha...The combination between biphasic calcium phosphate(BCP)and the osteomimetic porous microstructure obtained via freeze casting is hoped to achieve excellent bone regeneration,while the effects of HA and b-TCP ratio changes on the degradation and biological performance of the BCP scaffolds with this unique microstructure need to be determined.Here,we prepared the osteomimetic BCP scaffolds with different HA/b-TCP ratios(HA30/b-TCP70,HA50/b-TCP50,HA70/b-TCP30)and the effects of different HA/b-TCPHA/b-TCP ratios on the degradation and biological performance were studied in vitro and vivo.These BCP scaffolds with different HA/b-TCP ratios exhibited similar microstructure,mechanical performance,and protein absorption capability,while HA70/b-TCP30 BCP scaffolds showed an advisable degradation rate.Study in vitro confirmed the bio-compatibility and promotion on the proliferation,differentiation of MG63 cells in the porous osteomimetic BCP scaffolds with a HA/b-TCP ratio at 30:70.Implantation experiments also showed that the porous osteomimetic BCP scaffolds with a HA/b-TCP ratio at 30:70 had excellent bone regeneration capacity and proper degradation rate compatible with bone growth.These results reveal that the porous osteomimetic BCP scaffold with a HA/b-TCP ratio at 30:70 is a potential candidate of biodegradable bone substitutes used for bone repair.展开更多
The porous HA/BaTiO_(3)ceramics have the potential to exhibit superior capabilities to promote bone in-growth.However,there are few reports on in vivo studies.Here,we fabricated bio-inspired porous HA/BaTiO_(3)composi...The porous HA/BaTiO_(3)ceramics have the potential to exhibit superior capabilities to promote bone in-growth.However,there are few reports on in vivo studies.Here,we fabricated bio-inspired porous HA/BaTiO_(3)composites for bone repair via freeze-casting.These composites had a unique microstructure composed of the central canal and radically distributed lamellae,similar to the structure of nature cortical bone unite,the Haversian system.Polarized and non-polarized bio-inspired porous HA/BaTiO_(3)samples were implanted into the femoral condyle of the New Zealand rabbits.It was demonstrated that the polarization of the porous HA/BaTiO_(3)played a favorable part in bone regeneration.Moreover,the combination between the osteoconductivity of the microstructure and augmented osteogenic cell behavior induced by charges on surfaces of polarized porous HA/BaTiO_(3)facilitated bone penetration through the implants.The bio-inspired porous HA/BaTiO_(3)composites are demonstrated to be promising scaffolds for bone repair.展开更多
基金supported by the Hunan Provincial Science and Technology Department Project(2015WK3012)the National Natural Science Foundation of China(No.81571021)+3 种基金R&D of Key Project of Hunan Provincial Science and Technology Department(2022SK2010)R&D of Key Technology of Light Metal Air Battery,Transformation and Industrialization of Scientific and Technological Achievements of Hunan Province(2020GK2071)R&D of Key Technology and Materials of Magnesium Air Battery,Transformation of Scientific and Technological Achievements of Changsha City(Kh2005186)Technology Fundation(2021JCJQ-JJ-0432)。
文摘The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone.The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration.In this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a control.We then investigated the effect of additions of Y and Mn on alloys'properties.Our results show that Mn and Y can improve not only compression strength but also corrosion resistance.The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in vivo.The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or brain.Furthermore,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration.
基金Project(81571021) supported by the National Natural Science Foundation of ChinaProjects(2015WK3012,2018SK2017) supported by the Hunan Provincial Science and Technology Department Project,ChinaProject(20160301) supported by New Talent Project of the Third Xiangya Hospital of Central South University,China
文摘The effects of surface-modified porous titanium implants with different porosities and pore sizes on osseointegration were investigated in vivo.Three porous titanium implants(A30,A40 and A50 containing volume fractions of space-holder NaCl being 30%,40%and 50%,respectively)were manufactured by metal injection moulding(MIM).The surface-modified implants were implanted into muscles and femurs of hybrid male dogs.Interface osteogenic activity and histological bone ingrowth of porous titanium implants were evaluated at 28,56 and 84 d.The results showed that when additive space-holder amount of NaCl increased from 30%to 50%(volume fraction),the general porosity and mass fraction of macropores of porous titanium rose from 42.4%to 62.0%and from 8.3%to 69.3%,respectively.Histologic sections and fluorescent labeling showed that the A50 implant demonstrated a significantly higher osteogenic capacity at 28 d than other implants.Bone ingrowth into the A30 implant was lower than that into other implants at 84 d.Therefore,the pore structure of A50 implant was suitable for new bone tissue to grow into porous implant.
基金Project(2015WK3012) supported by the Hunan Provincial Science and Technology Department Project,ChinaProject(81571021) supported by the National Natural Science Foundation of China+2 种基金Project(225) supported by the High Level Health Personnel in Hunan Province,ChinaProject(621020094) supported by the State Key Laboratory of Powder Metallurgy of Central South University,ChinaProject(20160301) supported by New Talent Project of the Third Xiangya Hospital of Central South University,China
文摘Transfection efficiency of hydroxyapatite nanoparticles(HAnps)is relative to the particle size,morphology,surface charge,surface modifier and so on.This study prepared HAnps with doped Tb/Mg by hydrothermal synthesis method(HTSM)and investigated the effects of different Tb/Mg contents on the morphology,particle size,surface charge,composition and cellular endocytosis of HAnps.The results showed that Mg-HAnps possessed better dispersion ability than Tb-HAnps.With increasing doping content of Tb/Mg-HAnps,the granularity of Tb-HAnps increased,while that of Mg-HAnps declined.Both particle size and zeta potential of Mg-HAnps were lower than those of Tb-HAnps.7.5%Mg-doping HAnps presented relatively uniform slender rod morphology with average size of30nm,while10%Mg-doping HAnps were prone to agglomeration.Moreover,Mg-HAnps-GFP(green fluorescent protein)endocytosed by MG63cells was dotted in the perinuclear region,while Tb-HAnps were more likely to aggregate.In conclusion,as gene vectors,Mg-HAnps showed enhanced properties compared to Tb-HAnps.
基金This study was financially supported by the National Natural Science Foundation of China(No.81571021).
文摘The combination between biphasic calcium phosphate(BCP)and the osteomimetic porous microstructure obtained via freeze casting is hoped to achieve excellent bone regeneration,while the effects of HA and b-TCP ratio changes on the degradation and biological performance of the BCP scaffolds with this unique microstructure need to be determined.Here,we prepared the osteomimetic BCP scaffolds with different HA/b-TCP ratios(HA30/b-TCP70,HA50/b-TCP50,HA70/b-TCP30)and the effects of different HA/b-TCPHA/b-TCP ratios on the degradation and biological performance were studied in vitro and vivo.These BCP scaffolds with different HA/b-TCP ratios exhibited similar microstructure,mechanical performance,and protein absorption capability,while HA70/b-TCP30 BCP scaffolds showed an advisable degradation rate.Study in vitro confirmed the bio-compatibility and promotion on the proliferation,differentiation of MG63 cells in the porous osteomimetic BCP scaffolds with a HA/b-TCP ratio at 30:70.Implantation experiments also showed that the porous osteomimetic BCP scaffolds with a HA/b-TCP ratio at 30:70 had excellent bone regeneration capacity and proper degradation rate compatible with bone growth.These results reveal that the porous osteomimetic BCP scaffold with a HA/b-TCP ratio at 30:70 is a potential candidate of biodegradable bone substitutes used for bone repair.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.81571021 and 51072235).
文摘The porous HA/BaTiO_(3)ceramics have the potential to exhibit superior capabilities to promote bone in-growth.However,there are few reports on in vivo studies.Here,we fabricated bio-inspired porous HA/BaTiO_(3)composites for bone repair via freeze-casting.These composites had a unique microstructure composed of the central canal and radically distributed lamellae,similar to the structure of nature cortical bone unite,the Haversian system.Polarized and non-polarized bio-inspired porous HA/BaTiO_(3)samples were implanted into the femoral condyle of the New Zealand rabbits.It was demonstrated that the polarization of the porous HA/BaTiO_(3)played a favorable part in bone regeneration.Moreover,the combination between the osteoconductivity of the microstructure and augmented osteogenic cell behavior induced by charges on surfaces of polarized porous HA/BaTiO_(3)facilitated bone penetration through the implants.The bio-inspired porous HA/BaTiO_(3)composites are demonstrated to be promising scaffolds for bone repair.
