Loss of function of large tissues is an urgent clinical problem. Although the artificial microfluidic network fabricated in large tis- sue-engineered constructs has great promise, it is still difficult to develop an e...Loss of function of large tissues is an urgent clinical problem. Although the artificial microfluidic network fabricated in large tis- sue-engineered constructs has great promise, it is still difficult to develop an efficient vessel-like design to meet the requirements of the biomimetic vascular network for tissue engineering applications. In this study, we used a facile approach to fabricate a branched and multi-level vessel-like network in a large muscle scaffolds by combining stereolithography （SL） technology and enzymatic crosslinking mechanism. The morphology of microchannel cross-sections was characterized using micro-computed tomography. The square cross-sections were gradually changed to a seamless circular microfluidic network, which is similar to the natural blood vessel. In the different micro-channels, the velocity greatly affected the attachment and spread of Human Umbilical Vein Endothelial Cell （HUVEC）-Green Fluorescent Protein （GFP）. Our study demonstrated that the branched and multi-level microchannel network simulates biomimetic microenvironments to promote endothelialization. The gelatin scaffolds in the circular vessel-like networks will likely support myoblast and surrounding tissue for clinical use.展开更多
The macroporous calcium phosphate（CPC） cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligne...The macroporous calcium phosphate（CPC） cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede＇s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented rmre structure nrenared in this work might be a potential scaffold for bone tissue engineerinm展开更多
In this study,the macroporous calcium phosphate cement with oriented pore structure was prepared by freeze casting.SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected ...In this study,the macroporous calcium phosphate cement with oriented pore structure was prepared by freeze casting.SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction.The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede's principle.XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement.To improve the mechanical properties of the CPC scaffold,the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds.After reinforced with gelatine,the compressive strength of CPC/gelatin composite increased to 5.12 MPa,around 50 times greater than that of the unreinforced macroporous CPC scaffold,which was only 0.1 MPa.And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain.SEM examination of the specimens indicated good bonding between the cement and gelatine.In conclusion,the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this study might be a potential scaffold for bone tissue engineering.展开更多
Colloidal gels made of oppositely charged nanoparticles are a novel class of hydrogels and can exhibit pseudoplastic behavior which will enable them to mold easily into specific shapes.These moldable gels can be used ...Colloidal gels made of oppositely charged nanoparticles are a novel class of hydrogels and can exhibit pseudoplastic behavior which will enable them to mold easily into specific shapes.These moldable gels can be used as building blocks to self-assemble into integral scaffolds from bottom to up through electrostatic forces.However,they are too weak to maintain scaffold morphology just depending on interparticle interactions such as Van der Waals attraction and electrostatic forces especially for bone tissue engineering.In this study,oppositely charged gelatin nanoparticles were firstly prepared by two-step desolvation method,followed by the mixture with water to form colloid gels.To solve the problem of weak mechanical performance of colloid gels, gelatin macromolecules were introduced into the prepared gels to form blend gels.The blend gels can be easily processed into three-dimensional( 3D) porous scaffolds via motor assisted microsyringe( MAM)system,a nozzle-based rapid prototyping technology,under mild conditions.After fabrication the scaffolds were crosslinked by glutaraldehyde( GA,25% solution in water by weight),then the crosslinked gelatin macromolecules network could form to improve the mechanical properties of colloid gels.The average particle size and zeta potential of gelatin nanoparticles were measured by NanoZS instrument.The morphology and microstructures of scaffolds were characterized by macroscopic images.The mechanical properties of the scaffolds were studied by a universal material testing machine.展开更多
背景:脊髓损伤可导致不可修复的组织损伤和持续的感觉运动损伤,其治疗是一个相当大的挑战,因此一直受到临床科学家的极大关注。仿生三维支架已成为修复神经系统的有效选择。生物3D打印技术可根据个性化情况定制并快速打印出不同形状和...背景:脊髓损伤可导致不可修复的组织损伤和持续的感觉运动损伤,其治疗是一个相当大的挑战,因此一直受到临床科学家的极大关注。仿生三维支架已成为修复神经系统的有效选择。生物3D打印技术可根据个性化情况定制并快速打印出不同形状和尺寸的3D生物支架,精准控制其材料和细胞的相对空间结构,更好地模拟脊髓的相对解剖位置。目的:总结3D生物支架在脊髓损伤后组织修复和再生领域的研究进展。方法:以“生物3D打印、生物支架、三维支架、脊髓损伤”为中文检索词在中国知网和万方数据库进行检索,以“biology 3D printing,biological scaffold,three dimensional scaffold,spinal cord injury”为英文检索词在PubMed,Web of Science,Medline和Embase数据库进行检索。收集归纳3D生物打印支架联合干细胞移植治疗脊髓损伤的相关研究,最终纳入67篇文献进行分析。结果与结论:①生物3D打印技术可以制作出比传统生物支架的空间结构以及细胞分布更加符合脊髓组织的3D生物支架,可以更好地利用每种材料和细胞的特性使人工合成脊髓更加接近于天然脊髓组织,但是生物墨水中材料和细胞的选择仍是一大难题。②文章总结了载有不同材料和细胞的3D生物支架移植治疗脊髓损伤时所发挥的主要作用,发现胶原在减少胶质瘢痕方面的效果异常显著,同时可以减少脊髓空泡的形成;明胶具有更好的生物相容性,可以更好地保证移植细胞的存活;海藻酸盐的抗炎效果在脊髓损伤后微环境改变方面具有良好的疗效;透明质酸在促进神经分化的同时,可以更好地促进形成神经网络;壳聚糖则在血管重建上具有明显的优势。③未来对于3D生物支架对脊髓损伤不同病情不同分型分期的影响机制仍有待进一步研究。展开更多
基金This work was supported by National Natural Science Foundation of China （Grant No. 51375371） and the High-Tech Projects of China （Grant Nos. 2015AA020303 and 2015AA042503）.
文摘Loss of function of large tissues is an urgent clinical problem. Although the artificial microfluidic network fabricated in large tis- sue-engineered constructs has great promise, it is still difficult to develop an efficient vessel-like design to meet the requirements of the biomimetic vascular network for tissue engineering applications. In this study, we used a facile approach to fabricate a branched and multi-level vessel-like network in a large muscle scaffolds by combining stereolithography （SL） technology and enzymatic crosslinking mechanism. The morphology of microchannel cross-sections was characterized using micro-computed tomography. The square cross-sections were gradually changed to a seamless circular microfluidic network, which is similar to the natural blood vessel. In the different micro-channels, the velocity greatly affected the attachment and spread of Human Umbilical Vein Endothelial Cell （HUVEC）-Green Fluorescent Protein （GFP）. Our study demonstrated that the branched and multi-level microchannel network simulates biomimetic microenvironments to promote endothelialization. The gelatin scaffolds in the circular vessel-like networks will likely support myoblast and surrounding tissue for clinical use.
基金the National Natural Science Foundation of China (Nos.50772037 and 50732003)the Science and Technology Program of Guangdong Province of China (No. 2008A030102008)the Research Foundation for Doctors of Jiangxi University of Science and Technology
文摘The macroporous calcium phosphate（CPC） cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede＇s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented rmre structure nrenared in this work might be a potential scaffold for bone tissue engineerinm
基金National Natural Science Foundation of Chinagrant number:50772037 and 50732003+1 种基金Science and Technology Program ofGuangdong Province of Chinagrant number:2008A030102008
文摘In this study,the macroporous calcium phosphate cement with oriented pore structure was prepared by freeze casting.SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction.The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede's principle.XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement.To improve the mechanical properties of the CPC scaffold,the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds.After reinforced with gelatine,the compressive strength of CPC/gelatin composite increased to 5.12 MPa,around 50 times greater than that of the unreinforced macroporous CPC scaffold,which was only 0.1 MPa.And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain.SEM examination of the specimens indicated good bonding between the cement and gelatine.In conclusion,the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this study might be a potential scaffold for bone tissue engineering.
基金National Natural Science Foundations of China(Nos.30973105,31271035)Science and Technology Commission of Shanghai Municipality,China(No.11nm0506200)Ph.D.Programs Foundation of Ministry of Education of China(No.20130075110005)
文摘Colloidal gels made of oppositely charged nanoparticles are a novel class of hydrogels and can exhibit pseudoplastic behavior which will enable them to mold easily into specific shapes.These moldable gels can be used as building blocks to self-assemble into integral scaffolds from bottom to up through electrostatic forces.However,they are too weak to maintain scaffold morphology just depending on interparticle interactions such as Van der Waals attraction and electrostatic forces especially for bone tissue engineering.In this study,oppositely charged gelatin nanoparticles were firstly prepared by two-step desolvation method,followed by the mixture with water to form colloid gels.To solve the problem of weak mechanical performance of colloid gels, gelatin macromolecules were introduced into the prepared gels to form blend gels.The blend gels can be easily processed into three-dimensional( 3D) porous scaffolds via motor assisted microsyringe( MAM)system,a nozzle-based rapid prototyping technology,under mild conditions.After fabrication the scaffolds were crosslinked by glutaraldehyde( GA,25% solution in water by weight),then the crosslinked gelatin macromolecules network could form to improve the mechanical properties of colloid gels.The average particle size and zeta potential of gelatin nanoparticles were measured by NanoZS instrument.The morphology and microstructures of scaffolds were characterized by macroscopic images.The mechanical properties of the scaffolds were studied by a universal material testing machine.
文摘背景:脊髓损伤可导致不可修复的组织损伤和持续的感觉运动损伤,其治疗是一个相当大的挑战,因此一直受到临床科学家的极大关注。仿生三维支架已成为修复神经系统的有效选择。生物3D打印技术可根据个性化情况定制并快速打印出不同形状和尺寸的3D生物支架,精准控制其材料和细胞的相对空间结构,更好地模拟脊髓的相对解剖位置。目的:总结3D生物支架在脊髓损伤后组织修复和再生领域的研究进展。方法:以“生物3D打印、生物支架、三维支架、脊髓损伤”为中文检索词在中国知网和万方数据库进行检索,以“biology 3D printing,biological scaffold,three dimensional scaffold,spinal cord injury”为英文检索词在PubMed,Web of Science,Medline和Embase数据库进行检索。收集归纳3D生物打印支架联合干细胞移植治疗脊髓损伤的相关研究,最终纳入67篇文献进行分析。结果与结论:①生物3D打印技术可以制作出比传统生物支架的空间结构以及细胞分布更加符合脊髓组织的3D生物支架,可以更好地利用每种材料和细胞的特性使人工合成脊髓更加接近于天然脊髓组织,但是生物墨水中材料和细胞的选择仍是一大难题。②文章总结了载有不同材料和细胞的3D生物支架移植治疗脊髓损伤时所发挥的主要作用,发现胶原在减少胶质瘢痕方面的效果异常显著,同时可以减少脊髓空泡的形成;明胶具有更好的生物相容性,可以更好地保证移植细胞的存活;海藻酸盐的抗炎效果在脊髓损伤后微环境改变方面具有良好的疗效;透明质酸在促进神经分化的同时,可以更好地促进形成神经网络;壳聚糖则在血管重建上具有明显的优势。③未来对于3D生物支架对脊髓损伤不同病情不同分型分期的影响机制仍有待进一步研究。
