Poly(glycerol-dodecanoate)(PGD)has aroused increasing attention in biomedical engineering for its degradability,shape memory and rubber-like mechanical properties,giving it potential to fabricate intelligent implants ...Poly(glycerol-dodecanoate)(PGD)has aroused increasing attention in biomedical engineering for its degradability,shape memory and rubber-like mechanical properties,giving it potential to fabricate intelligent implants for soft tissues.Adjustable degradation is important for biodegradable implants and is affected by various factors.The mechanical load has been shown to play an important role in regulating polymer degradation in vivo.An in-depth investigation of PGD degradation under mechanical load is essential for adjusting its degradation behavior after implantation,further guiding to regulate degradation behavior of soft tissue implants made by PGD.In vitro degradation of PGD under different compressive and tensile load has proceeded in this study and describes the relationships by empirical equations.Based on the equations,a continuum damage model is designed to simulate surface erosion degradation of PGD under stress through finite element analysis,which provides a protocol for PGD implants with different geometric structures at varied mechanical conditions and provides solutions for predicting in vivo degradation processes,stress distribution during degradation and optimization of the loaded drug release.展开更多
MicroRNAs （miRNAs） are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothes...MicroRNAs （miRNAs） are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural devel- opment. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in v/vo. Further investigation demonstrated that the activation of gluta- mate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin （DCX） expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.展开更多
基金supported by the National Natural Science Foundation of China(T2288101,12172034,U20A20390,11827803)Beijing Municipal Natural Science Foundation(7212205)the 111 project(B13003)and the Fundamental Research Funds for the Central Universities。
文摘Poly(glycerol-dodecanoate)(PGD)has aroused increasing attention in biomedical engineering for its degradability,shape memory and rubber-like mechanical properties,giving it potential to fabricate intelligent implants for soft tissues.Adjustable degradation is important for biodegradable implants and is affected by various factors.The mechanical load has been shown to play an important role in regulating polymer degradation in vivo.An in-depth investigation of PGD degradation under mechanical load is essential for adjusting its degradation behavior after implantation,further guiding to regulate degradation behavior of soft tissue implants made by PGD.In vitro degradation of PGD under different compressive and tensile load has proceeded in this study and describes the relationships by empirical equations.Based on the equations,a continuum damage model is designed to simulate surface erosion degradation of PGD under stress through finite element analysis,which provides a protocol for PGD implants with different geometric structures at varied mechanical conditions and provides solutions for predicting in vivo degradation processes,stress distribution during degradation and optimization of the loaded drug release.
基金This work was supported by grants from the National Natural Science Foundation of China （Grant Nos. 31000478, 31100777 and 31271378）.
文摘MicroRNAs （miRNAs） are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural devel- opment. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in v/vo. Further investigation demonstrated that the activation of gluta- mate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin （DCX） expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.
