The development of functional materials for osteoporosis is ultimately required for bone remodeling.However,grafts were accompanied by increasing pro-inflammatory cytokines that impaired bone formation.In this work,na...The development of functional materials for osteoporosis is ultimately required for bone remodeling.However,grafts were accompanied by increasing pro-inflammatory cytokines that impaired bone formation.In this work,nano-hydroxyapatite(n-HA)/resveratrol(Res)/chitosan(CS)composite microspheres were designed to create a beneficial microenvironment and help improve the osteogenesis by local sustained release of Res.Study of in vitro release confirmed the feasibility of n-HA/Res/CS microspheres for controlled Res release.Notably,microspheres had anti-inflammatory activity evidenced by the decreased expression of pro-inflammatory cytokines TNF-α,IL-1βand iNOS in RAW264.7 cells in a dose dependent manner.Further,enhanced adhesion and proliferation of BMSCs seeded onto microspheres demonstrated that composite microspheres were conducive to cell growth.The ability to enhance osteo-differentiation was supported by up-regulation of Runx2,ALP,Col-1 and OCN,and substantial mineralization in osteogenic medium.When implanted into bone defects in the osteoporotic rat femoral condyles,enhanced entochondrostosis and bone regeneration suggested that the n-HA/Res/CS composite microspheres were more favorable for impaired fracture healing.The results indicated that optimized n-HA/Res/CS composite microspheres could serve as promising multifunctional fillers for osteoporotic bone defect/fracture treatment.展开更多
Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted exte...Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted extensive research interest for electric energy storage applications.However,a low dielectric breakdown field(Eb)limits an energy density and its further development.In this work,a highly efficient method was proposed to fabricate high-energy-density Ag(Nb,Ta)O_(3) capacitor films on Si substrates,using a two-step process combining radio frequency(RF)-magnetron sputtering at 450℃and post-deposition rapid thermal annealing(RTA).The RTA process at 700℃led to sufficient crystallization of nanograins in the film,hindering their lateral growth by employing short annealing time of 5 min.The obtained Ag(Nb,Ta)O_(3) films showed an average grain size(D)of~14 nm(obtained by Debye-Scherrer formula)and a slender room temperature(RT)polarization-electric field(P-E)loop(Pr≈3.8 mC·cm^(−2) and P_(max)≈38 mC·cm^(−2) under an electric field of~3.3 MV·cm^(−1)),the P-E loop corresponding to a high recoverable energy density(W_(rec))of~46.4 J·cm^(−3) and an energy efficiency(η)of~80.3%.Additionally,by analyzing temperature-dependent dielectric property of the film,a significant downshift of the diffused phase transition temperature(T_(M2-M3))was revealed,which indicated the existence of a stable relaxor-like AFE phase near the RT.The downshift of the T_(M2-M3) could be attributed to a nanograin size and residual tensile strain of the film,and it led to excellent temperature stability(20-240℃)of the energy storage performance of the film.Our results indicate that the Ag(Nb,Ta)O_(3) film is a promising candidate for electrical energy storage applications.展开更多
Brain tissues that are severely damaged by traumatic brain injury(TBI)is hardly regenerated,which leads to a cavity or a repair with glial scarring.Stem-cell therapy is one viable option to treat TBI-caused brain tiss...Brain tissues that are severely damaged by traumatic brain injury(TBI)is hardly regenerated,which leads to a cavity or a repair with glial scarring.Stem-cell therapy is one viable option to treat TBI-caused brain tissue damage,whose use is,whereas,limited by the low survival rate and differentiation efficiency of stem cells.To approach this problem,we developed an injectable hydrogel using imidazole groups-modified gelatin methacrylate(GelMA-imid).In addition,polydopamine(PDA)nanoparticles were used as carrier for stromal-cell derived factor-1(SDF-1α).GelMA-imid hydrogel loaded with PDA@SDF-1αnanoparticles and human amniotic mesenchymal stromal cells(hAMSCs)were injected into the damaged area in an in-vivo cryogenic injury model in rats.The hydrogel had low module and its average pore size was 204.61±41.41 nm,which were suitable for the migration,proliferation and differentiation of stem cells.In-vitro cell scratch and differentiation assays showed that the imidazole groups and SDF-1αcould promote the migration of hAMSCs to injury site and their differentiation into nerve cells.The highest amount of nissl body was detected in the group of GelMA-imid/SDF-1α/hAMSCs hydrogel in the in-vivo model.Additionally,histological analysis showed that GelMA-imid/SDF-1α/hAMSCs hydrogel could facilitate the regeneration of regenerate endogenous nerve cells.In summary,the GelMA-imid/SDF-1α/hAMSCs hydrogel promoted homing and differentiation of hAMSCs into nerve cells,and showed great application potential for the physiological recovery of TBI.展开更多
基金supported by the National Natural Science Foundation of China(81460173/81860326/81960268)the Department of Science and Technology of Yunnan Province of China(2017FF117(-062)/2018FE001(-137)/2018FE001(-125)/2019ZF011-2).
文摘The development of functional materials for osteoporosis is ultimately required for bone remodeling.However,grafts were accompanied by increasing pro-inflammatory cytokines that impaired bone formation.In this work,nano-hydroxyapatite(n-HA)/resveratrol(Res)/chitosan(CS)composite microspheres were designed to create a beneficial microenvironment and help improve the osteogenesis by local sustained release of Res.Study of in vitro release confirmed the feasibility of n-HA/Res/CS microspheres for controlled Res release.Notably,microspheres had anti-inflammatory activity evidenced by the decreased expression of pro-inflammatory cytokines TNF-α,IL-1βand iNOS in RAW264.7 cells in a dose dependent manner.Further,enhanced adhesion and proliferation of BMSCs seeded onto microspheres demonstrated that composite microspheres were conducive to cell growth.The ability to enhance osteo-differentiation was supported by up-regulation of Runx2,ALP,Col-1 and OCN,and substantial mineralization in osteogenic medium.When implanted into bone defects in the osteoporotic rat femoral condyles,enhanced entochondrostosis and bone regeneration suggested that the n-HA/Res/CS composite microspheres were more favorable for impaired fracture healing.The results indicated that optimized n-HA/Res/CS composite microspheres could serve as promising multifunctional fillers for osteoporotic bone defect/fracture treatment.
基金support from the National Natural Science Foundation of China (Grant Nos.51772175,52072218,and 52002192)Natural Science Foundation of Shandong Province (Grant Nos.ZR2020QE042,ZR2022ZD39,and ZR2022ME031)+6 种基金the Science,Education and Industry Integration Pilot Projects of Qilu University of Technology (Shandong Academy of Sciences) (Grant Nos.2022GH018 and 2022PY055)support from the Jinan City Science and Technology Bureau (Grant No.2021GXRC055)the Education Department of Hunan Province/Xiangtan University (Grant No.KZ0807969)funding for top talents at Qilu University of Technology (Shandong Academy of Sciences)support from the Jiangsu Province NSFC (Grant No.BK20180764)support from the National Key R&D Program of China (Grant No.2021YFB3601504)Natural Science Foundation of Shandong Province (Grant No.ZR2020KE019).
文摘Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted extensive research interest for electric energy storage applications.However,a low dielectric breakdown field(Eb)limits an energy density and its further development.In this work,a highly efficient method was proposed to fabricate high-energy-density Ag(Nb,Ta)O_(3) capacitor films on Si substrates,using a two-step process combining radio frequency(RF)-magnetron sputtering at 450℃and post-deposition rapid thermal annealing(RTA).The RTA process at 700℃led to sufficient crystallization of nanograins in the film,hindering their lateral growth by employing short annealing time of 5 min.The obtained Ag(Nb,Ta)O_(3) films showed an average grain size(D)of~14 nm(obtained by Debye-Scherrer formula)and a slender room temperature(RT)polarization-electric field(P-E)loop(Pr≈3.8 mC·cm^(−2) and P_(max)≈38 mC·cm^(−2) under an electric field of~3.3 MV·cm^(−1)),the P-E loop corresponding to a high recoverable energy density(W_(rec))of~46.4 J·cm^(−3) and an energy efficiency(η)of~80.3%.Additionally,by analyzing temperature-dependent dielectric property of the film,a significant downshift of the diffused phase transition temperature(T_(M2-M3))was revealed,which indicated the existence of a stable relaxor-like AFE phase near the RT.The downshift of the T_(M2-M3) could be attributed to a nanograin size and residual tensile strain of the film,and it led to excellent temperature stability(20-240℃)of the energy storage performance of the film.Our results indicate that the Ag(Nb,Ta)O_(3) film is a promising candidate for electrical energy storage applications.
基金financially supported by the Science and Technology Project of Guangdong Province(No.2015A020212021)Medical Health Science and Technology Project of Zhejiang Provincial Health Commission(No.2020KY625)+4 种基金Zhejiang Provincial Department of Education(No.Y201636248)Natural Science Foundation of Zhejiang Province(No.LQY17H140023)Science Technology Department of Zhejiang Province(No.2017C33168)Zhejiang Provincial Basic Public Welfare Research Project(No.GJ19H140001)China's National Key R&D Programs(No.2018YFB0407204).
文摘Brain tissues that are severely damaged by traumatic brain injury(TBI)is hardly regenerated,which leads to a cavity or a repair with glial scarring.Stem-cell therapy is one viable option to treat TBI-caused brain tissue damage,whose use is,whereas,limited by the low survival rate and differentiation efficiency of stem cells.To approach this problem,we developed an injectable hydrogel using imidazole groups-modified gelatin methacrylate(GelMA-imid).In addition,polydopamine(PDA)nanoparticles were used as carrier for stromal-cell derived factor-1(SDF-1α).GelMA-imid hydrogel loaded with PDA@SDF-1αnanoparticles and human amniotic mesenchymal stromal cells(hAMSCs)were injected into the damaged area in an in-vivo cryogenic injury model in rats.The hydrogel had low module and its average pore size was 204.61±41.41 nm,which were suitable for the migration,proliferation and differentiation of stem cells.In-vitro cell scratch and differentiation assays showed that the imidazole groups and SDF-1αcould promote the migration of hAMSCs to injury site and their differentiation into nerve cells.The highest amount of nissl body was detected in the group of GelMA-imid/SDF-1α/hAMSCs hydrogel in the in-vivo model.Additionally,histological analysis showed that GelMA-imid/SDF-1α/hAMSCs hydrogel could facilitate the regeneration of regenerate endogenous nerve cells.In summary,the GelMA-imid/SDF-1α/hAMSCs hydrogel promoted homing and differentiation of hAMSCs into nerve cells,and showed great application potential for the physiological recovery of TBI.
