It is still a challenge to optimize the component distribution and microporous structures in scaffolds for tailoring biodegradation(ion releasing)and enhancing bone defect repair within an expected time stage.Herein,t...It is still a challenge to optimize the component distribution and microporous structures in scaffolds for tailoring biodegradation(ion releasing)and enhancing bone defect repair within an expected time stage.Herein,the core–shell-typed nonstoichiometric wollastonite(4%and 10%Mg-doping calcium silicate;CSiMg4,CSiMg10)macroporous scaffolds with microporous shells(adding~μ10 μm PS microspheres into shell-layer slurry)were fabricated via 3D printing.The initial mechanical properties and bio-dissolution(ion releasing)in vitro,and osteogenic capacity in vivo of the bioceramic scaffolds were evaluated systematically.It was shown that endowing high-density micropores in the sparingly dissolvable CSiMg10 or dissolvable CSiMg4 shell layer inevitably led to nearly 30%reduction of compressive strength,but such micropores could readily tune the ion release behaviour of the scaffolds(CSiMg4@CSiMg10 vs.CSiMg4@CSiMg10-p;CSiMg10@CSiMg4 vs.CSiMg10@CSiMg4-p).Based on the in rabbit femoral bone defect repair model,the 3D μCT reconstruction and histological observation demonstrated that the CSiMg4@CSiMg10-p scaffolds displayed markedly higher osteogenic capability than the other scaffolds after 12weeks of implantation.It demonstrated that core–shell bioceramic 3D printing technique can be developed to fabricate single-phase or biphasic bioactive ceramic scaffolds with accurately tailored filament biodegradation for promoting bone defect regeneration and repair in some specific pathological conditions.展开更多
Herein, we presented a novel biodegradable copolymer via the chain extending reaction of poly(pdioxanone)-co-poly(2-(2-hydroxyethoxy) benzoate)(PPDO-co-PDHB) prepolymer with hexamethylene diisocyanate(HDI) as a chain ...Herein, we presented a novel biodegradable copolymer via the chain extending reaction of poly(pdioxanone)-co-poly(2-(2-hydroxyethoxy) benzoate)(PPDO-co-PDHB) prepolymer with hexamethylene diisocyanate(HDI) as a chain extender. The structures and molecular weight of PPDO-co-PDHB prepolymer and PPDO-co-PDHB-PU chain-extended copolymer are characterized via hydrogen nuclear magnetic resonance spectroscopy(1 H NMR) and viscosity test. The relationship between the molecular structures and properties of the chain-extended copolymers is established. The PPDO-co-PDHB-PU copolymers possess a better thermal stability comparing with the PPDO homopolymer. The study of mechanical properties shows that the elongation-at-break of PPDO-co-PDHB-PU is much higher than that of PPDO. The investigation of hydrolytic degradation behaviors indicates the degradation rate of PPDO can be controlled by adjusting the PDHB compositions, and proves that chain-extended copolymers exhibit an excellent hydrolytic stability being better than that of PPDO.展开更多
基金This work was jointly supported by the Key Research and Development Program of Zhejiang Province Foundation(2019C03027)the Zhejiang Provincial Basic Public Welfare Project of China(LGF18H140003)the Science and Technology Department of Zhejiang Province Foundation(LGF20H060016 and GF18E020001).
文摘It is still a challenge to optimize the component distribution and microporous structures in scaffolds for tailoring biodegradation(ion releasing)and enhancing bone defect repair within an expected time stage.Herein,the core–shell-typed nonstoichiometric wollastonite(4%and 10%Mg-doping calcium silicate;CSiMg4,CSiMg10)macroporous scaffolds with microporous shells(adding~μ10 μm PS microspheres into shell-layer slurry)were fabricated via 3D printing.The initial mechanical properties and bio-dissolution(ion releasing)in vitro,and osteogenic capacity in vivo of the bioceramic scaffolds were evaluated systematically.It was shown that endowing high-density micropores in the sparingly dissolvable CSiMg10 or dissolvable CSiMg4 shell layer inevitably led to nearly 30%reduction of compressive strength,but such micropores could readily tune the ion release behaviour of the scaffolds(CSiMg4@CSiMg10 vs.CSiMg4@CSiMg10-p;CSiMg10@CSiMg4 vs.CSiMg10@CSiMg4-p).Based on the in rabbit femoral bone defect repair model,the 3D μCT reconstruction and histological observation demonstrated that the CSiMg4@CSiMg10-p scaffolds displayed markedly higher osteogenic capability than the other scaffolds after 12weeks of implantation.It demonstrated that core–shell bioceramic 3D printing technique can be developed to fabricate single-phase or biphasic bioactive ceramic scaffolds with accurately tailored filament biodegradation for promoting bone defect regeneration and repair in some specific pathological conditions.
基金supported by the National Natural Science Foundation of China (No. U19A2095)the Sichuan Science and Technology Program (No. 2017SZDZX0015)the Fundamental Research Funds for the Central Universities。
文摘Herein, we presented a novel biodegradable copolymer via the chain extending reaction of poly(pdioxanone)-co-poly(2-(2-hydroxyethoxy) benzoate)(PPDO-co-PDHB) prepolymer with hexamethylene diisocyanate(HDI) as a chain extender. The structures and molecular weight of PPDO-co-PDHB prepolymer and PPDO-co-PDHB-PU chain-extended copolymer are characterized via hydrogen nuclear magnetic resonance spectroscopy(1 H NMR) and viscosity test. The relationship between the molecular structures and properties of the chain-extended copolymers is established. The PPDO-co-PDHB-PU copolymers possess a better thermal stability comparing with the PPDO homopolymer. The study of mechanical properties shows that the elongation-at-break of PPDO-co-PDHB-PU is much higher than that of PPDO. The investigation of hydrolytic degradation behaviors indicates the degradation rate of PPDO can be controlled by adjusting the PDHB compositions, and proves that chain-extended copolymers exhibit an excellent hydrolytic stability being better than that of PPDO.