Four-dimensional (4D) printing is an emerging and highly innovative additive manufacturing process by which to fabricate pre-designed,self-assembly structures with the ability to transform over time.However,one of the...Four-dimensional (4D) printing is an emerging and highly innovative additive manufacturing process by which to fabricate pre-designed,self-assembly structures with the ability to transform over time.However,one of the critical challenges of 4D printing is the lack of advanced 4D printing systems that not only meet all the essential requirements of shape change but also possess smart,dynamic capabilities to spatiotemporally and instantly control the shape-transformation process.Here,we present a facile 4D printing platform which incorporates nanomaterials into the conventional stimuli-responsive polymer,allowing the 4D printed object to achieve a dynamic and remote controlled,on-time and position shape transformation.A proof-of-concept 4D printed brain model was created using near-infrared light (NIR) responsive nanocomposite to evaluate the capacity for controllable 4D transformation,and the feasibility of photothermal stimulation for modulating neural stem cell behaviors.This novel 4D printing strategy can not only be used to create dynamic 3D patterned biological structures that can spatiotemporally control their shapes or behaviors of transformation under a human benign stimulus (NIR),but can also provide a potential method for building complex self-morphing objects for widespread applications.展开更多
Although the process by which the cortical tissues of the brain fold has been the subject of considerable study and debate over the past few decades,a single mechanistic description of the phenomenon has yet to be ful...Although the process by which the cortical tissues of the brain fold has been the subject of considerable study and debate over the past few decades,a single mechanistic description of the phenomenon has yet to be fully accepted.Rather,two competing explanations of cortical folding have arisen in recent years;known as the axonal tension and the differential tangential expansion models.In the present review,these two models are introduced by analyzing the computational,theoretical,materials-based,and cell studies which have yielded them.Then Four-dimensional bioprinting is presented as a powerful technology which can not only be used to test both models of cortical folding de novo,but can also be used to explore the reciprocal effects that folding associated mechanical stresses may have on neural development.Therein,the fabrication of‘smart’tissue models which can accurately simulate the in vivo folding process and recapitulate physiologically relevant stresses are introduced.We also provide a general description of both cortical neurobiology as well as the cellular basis of cortical folding.Our discussion also entails an overview of both 3D and 4D bioprinting technologies,as well as a brief commentary on recent advancements in printed central nervous system tissue engineering.展开更多
文摘Four-dimensional (4D) printing is an emerging and highly innovative additive manufacturing process by which to fabricate pre-designed,self-assembly structures with the ability to transform over time.However,one of the critical challenges of 4D printing is the lack of advanced 4D printing systems that not only meet all the essential requirements of shape change but also possess smart,dynamic capabilities to spatiotemporally and instantly control the shape-transformation process.Here,we present a facile 4D printing platform which incorporates nanomaterials into the conventional stimuli-responsive polymer,allowing the 4D printed object to achieve a dynamic and remote controlled,on-time and position shape transformation.A proof-of-concept 4D printed brain model was created using near-infrared light (NIR) responsive nanocomposite to evaluate the capacity for controllable 4D transformation,and the feasibility of photothermal stimulation for modulating neural stem cell behaviors.This novel 4D printing strategy can not only be used to create dynamic 3D patterned biological structures that can spatiotemporally control their shapes or behaviors of transformation under a human benign stimulus (NIR),but can also provide a potential method for building complex self-morphing objects for widespread applications.
基金supported by NSF MME program grant#1642186March of Dimes Foundation’s Gene Discovery and Translational Research Grant and NIH Director’s New Innovator Award 1DP2EB020549-01.
文摘Although the process by which the cortical tissues of the brain fold has been the subject of considerable study and debate over the past few decades,a single mechanistic description of the phenomenon has yet to be fully accepted.Rather,two competing explanations of cortical folding have arisen in recent years;known as the axonal tension and the differential tangential expansion models.In the present review,these two models are introduced by analyzing the computational,theoretical,materials-based,and cell studies which have yielded them.Then Four-dimensional bioprinting is presented as a powerful technology which can not only be used to test both models of cortical folding de novo,but can also be used to explore the reciprocal effects that folding associated mechanical stresses may have on neural development.Therein,the fabrication of‘smart’tissue models which can accurately simulate the in vivo folding process and recapitulate physiologically relevant stresses are introduced.We also provide a general description of both cortical neurobiology as well as the cellular basis of cortical folding.Our discussion also entails an overview of both 3D and 4D bioprinting technologies,as well as a brief commentary on recent advancements in printed central nervous system tissue engineering.
