目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调...目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调节仍有待研究。方法本实验制备了模拟骨髓力学微环境不同位置处基质刚度(1、10、34 k Pa)的聚丙烯酰胺水凝胶培养基底;培养间充质干细胞细胞系C3H10T1/2,利用18α-GA抑制C3H10T1/2中Cx43功能;提取BMSCs条件性敲除(c KO)Cx43小鼠(Prx1-Cre;Cx43 flox/flox)和同窝对照flox小鼠(Cx43 flox/flox)原代BMSCs进一步验证。结果抑制Cx43均会导致BMSCs在10、34 k Pa基质刚度上的成脂能力显著下降,而对1 k Pa上BMSCs成脂能力无影响。相比于1 k Pa和34 k Pa,在10 k Pa基质刚度上抑制Cx43导致了BMSCs成骨能力显著下降。在不同基质刚度上抑制BMSCs上Cx43均会导致糖酵解和线粒体融合裂变相关基因表达显著变化,以及成脂和成骨分化过程中ATP的生成。结论BMSCs响应骨髓力学微环境,较软的基质刚度可能对成脂能力有一定程度的恢复作用,而Cx43可能通过代谢途径参与了基质刚度对BMSCs分化的调节。展开更多
Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.Howe...Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.展开更多
文摘目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调节仍有待研究。方法本实验制备了模拟骨髓力学微环境不同位置处基质刚度(1、10、34 k Pa)的聚丙烯酰胺水凝胶培养基底;培养间充质干细胞细胞系C3H10T1/2,利用18α-GA抑制C3H10T1/2中Cx43功能;提取BMSCs条件性敲除(c KO)Cx43小鼠(Prx1-Cre;Cx43 flox/flox)和同窝对照flox小鼠(Cx43 flox/flox)原代BMSCs进一步验证。结果抑制Cx43均会导致BMSCs在10、34 k Pa基质刚度上的成脂能力显著下降,而对1 k Pa上BMSCs成脂能力无影响。相比于1 k Pa和34 k Pa,在10 k Pa基质刚度上抑制Cx43导致了BMSCs成骨能力显著下降。在不同基质刚度上抑制BMSCs上Cx43均会导致糖酵解和线粒体融合裂变相关基因表达显著变化,以及成脂和成骨分化过程中ATP的生成。结论BMSCs响应骨髓力学微环境,较软的基质刚度可能对成脂能力有一定程度的恢复作用,而Cx43可能通过代谢途径参与了基质刚度对BMSCs分化的调节。
基金supported by the following funds:National Natural Science Foundation of China(51935014,52165043)Jiangxi Provincial Cultivation Program for Academic and Technical Leaders of Major Subjects(20225BCJ23008)+1 种基金Jiangxi Provincial Natural Science Foundation(20224ACB204013,20224ACB214008)Scientific Research Project of Anhui Universities(KJ2021A1106)。
文摘Magnesium(Mg)alloys are considered to be a new generation of revolutionary medical metals.Laser-beam powder bed fusion(PBF-LB)is suitable for fabricating metal implants withpersonalized and complicated structures.However,the as-built part usually exhibits undesirable microstructure and unsatisfactory performance.In this work,WE43 parts were firstly fabricated by PBF-LB and then subjected to heat treatment.Although a high densification rate of 99.91%was achieved using suitable processes,the as-built parts exhibited anisotropic and layeredmicrostructure with heterogeneously precipitated Nd-rich intermetallic.After heat treatment,fine and nano-scaled Mg24Y5particles were precipitated.Meanwhile,theα-Mg grainsunderwent recrystallization and turned coarsened slightly,which effectively weakened thetexture intensity and reduced the anisotropy.As a consequence,the yield strength and ultimate tensile strength were significantly improved to(250.2±3.5)MPa and(312±3.7)MPa,respectively,while the elongation was still maintained at a high level of 15.2%.Furthermore,the homogenized microstructure reduced the tendency of localized corrosion and favoredthe development of uniform passivation film.Thus,the degradation rate of WE43 parts was decreased by an order of magnitude.Besides,in-vitro cell experiments proved their favorable biocompatibility.
