Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro re...Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro replacements for bone transplantation and overcoming the limitations of natural bone grafts.In this study,we developed an innovative bone engineering scaffold based on gelatin methacrylate(GelMA)hydrogel,obtained via a two-step procedure:first,solid lipid nanoparticles(SLNs)were loaded with resveratrol(Res),a drug that can promote osteogenic differentiation and bone formation;these particles were then encapsulated at different concentrations(0.01%,0.02%,0.04%and 0.08%)in GelMA to obtain the final Res-SLNs/GelMA scaffolds.The effects of these scaffolds on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and bone regeneration in rat cranial defects were evaluated using various characterization assays.Our in vitro and in vivo investigations demonstrated that the different Res-SLNs/GelMA scaffolds improved the osteogenic differentiation of BMSCs,with the ideally slow and steady release of Res;the optimal scaffold was 0.02 Res-SLNs/GelMA.Therefore,the 0.02 Res-SLNs/GelMA hydrogel is an appropriate release system for Res with good biocompatibility,osteoconduction and osteoinduction,thereby showing potential for application in bone tissue engineering.展开更多
An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethyle...An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8.As a result of such a[4+2]cycloaddition process,4,6,6-trisubstituted-1,3-oxazinan-2-ones 6aa,6af-6au,7ba,7bf-7bw and 6,6-spiro containing 1,3-oxazinan-2-ones 9ad,9ae,10ba-10bg were obtained in 36%-96%yields and with moderate to excellent diastereoselectivities.In addition,the synthesis of(±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.展开更多
Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of(hetero)aryl halides with secondary phosphine oxides and phosphites.Only 3—5 mol%CuI and ligands were r...Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of(hetero)aryl halides with secondary phosphine oxides and phosphites.Only 3—5 mol%CuI and ligands were required to ensure coupling with a number of(hetero)aryl bromides and iodides to complete at 120 ℃ in 10—20 h.展开更多
基金supported by the Natural Science Foundation of Anhui Province(Grant No.2008085QH362)Key Program of Anhui Educational Committee(Grant No.KJ2020ZD51)+2 种基金Translational Medicine Key Projects of Bengbu Medical College(Grant Nos.BYTM2019006 and BYTM 2019012)Scientific Research Innovation Team of Bengbu Medical College(Grant No.BYKC201910)512 Talents Development Project of Bengbu Medical College(Grant Nos.by51202302 and by51202309).
文摘Critical-sized bone defects caused by traumatic fractures,tumour resection and congenital malformation are unlikely to heal spontaneously.Bone tissue engineering is a promising strategy aimed at developing in vitro replacements for bone transplantation and overcoming the limitations of natural bone grafts.In this study,we developed an innovative bone engineering scaffold based on gelatin methacrylate(GelMA)hydrogel,obtained via a two-step procedure:first,solid lipid nanoparticles(SLNs)were loaded with resveratrol(Res),a drug that can promote osteogenic differentiation and bone formation;these particles were then encapsulated at different concentrations(0.01%,0.02%,0.04%and 0.08%)in GelMA to obtain the final Res-SLNs/GelMA scaffolds.The effects of these scaffolds on osteogenic differentiation of bone marrow mesenchymal stem cells(BMSCs)and bone regeneration in rat cranial defects were evaluated using various characterization assays.Our in vitro and in vivo investigations demonstrated that the different Res-SLNs/GelMA scaffolds improved the osteogenic differentiation of BMSCs,with the ideally slow and steady release of Res;the optimal scaffold was 0.02 Res-SLNs/GelMA.Therefore,the 0.02 Res-SLNs/GelMA hydrogel is an appropriate release system for Res with good biocompatibility,osteoconduction and osteoinduction,thereby showing potential for application in bone tissue engineering.
基金the National Natural Science Foundation of China(No.21772027 to B.-G.Wei and 21702032 to C.-M.Si)for financial support.
文摘An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8.As a result of such a[4+2]cycloaddition process,4,6,6-trisubstituted-1,3-oxazinan-2-ones 6aa,6af-6au,7ba,7bf-7bw and 6,6-spiro containing 1,3-oxazinan-2-ones 9ad,9ae,10ba-10bg were obtained in 36%-96%yields and with moderate to excellent diastereoselectivities.In addition,the synthesis of(±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.
基金The authors are grateful to Chinese Academy of Sciences(supported by the Strategic Priority Research Program,grant XDB20020200&QYZDJ-SSW-SLH029)the National Natural Science Foundation of China(grant 21621002,21831009 and 21991110)for their financial support.
文摘Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of(hetero)aryl halides with secondary phosphine oxides and phosphites.Only 3—5 mol%CuI and ligands were required to ensure coupling with a number of(hetero)aryl bromides and iodides to complete at 120 ℃ in 10—20 h.
