采用反求工程和快速原型技术精确定制骨组织工程支架(英文)

Fabrication of customized anatomical-shaped bone tissue engineering scaffolds with reverse engineering and rapid prototyping technology

背景:组织工程基本原理是从患者获取组织,经体外培养扩增种子细胞,接种在支架内,通过支架引导形成三维外形的组织,最后植入该患者体内以替代病损组织的功能,以后随着新生血管长入,支架逐步溶解,新生组织最终与周围组织完全融合。目的:探讨应用反求工程和快速原型技术定制个体特异的解剖外形骨组织工程支架的可行性,克服常规制作方法的缺陷。设计:定制个体特异的解剖外形骨组织工程支架方法。单位:解放军广州军区广州总医院全军创伤骨科中心。材料:支架CAD设计在广东省机械研究所CAD培训中心完成,支架快速成型制作在广东省龙创域公司完成,快速成型工艺为立体光固化工艺,采用材料为光敏树脂。方法:实验于2004-10/2005-01在广州军区广州总医院全军创伤骨科中心完成。按反求工程的基本原理,采用医学CT/MRI扫描获取患者骨骼的分层图像信息,采用计算机辅助技术进行三维重建和曲面重构建立骨骼感兴趣区域的解剖模型,并在建立的解剖模型的外形轮廓内进行支架内部结构的计算机辅助设计,建立其计算机辅助设计模型,最后采用快速成型工艺精确制作骨组织工程支架的原型。主要观察指标:①CT/MRI扫描三维重建与解剖建模结果。②个体化组织工程支架的内部结构设计结果。③个体化组织工程支架快速成型制作。结果:①经CT/MRI图像三维重建,建立了骨关节解剖模型。②计算机辅助设计软件设计支架内部结构成功地建立了骨组织工程支架的实体模型。③骨组织工程支架CAD模型指导快速成型工艺成功地制作了个体化解剖外形的支架,制作的骨组织工程支架内部结构非常精细,具有高孔隙率和较好的孔隙相互连通性能。结论:采用反求工程和先进制造技术,可以任意制作个体化解剖外形的组织工程支架;在所有快速成型工艺中,以立体光固化成型精度最高,表面光滑、成型质量最好。

BACKGROUND： The rudiment of tissue engineering is to obtain tissue from patients, The cells are expanded into a population through cellular culture, and seeded into scaffolds, which can aceommodate and guide the growth and proliferation of new cells in the three-dimensional scaffolds. At last, the constructed tissue is transplanted in vivo to repair or replace damaged or diseased tissues, Afterward neovascularization of the graft, the scaffolds are absorbed gradually. Finally, the new tissue replaces completely the damaged mr diseased tissues OBJECTIVE： To evaluate the feasibility of designing and fabricating customized anatomical-shaped bone tissue-engineering scaffolds with reverse engineering and rapid prototyping （RP） techniques, To avoid the disadvantage of the conventional fabricated methods of the scaffolds. DESIGN： The method of fabricating customized anatomical-shaped bone tissue engineering scaffolds, SETTING： Computer-aided design （CAD） of the scaffold was conducted in CAD training center, Guangdong Machinery, Research Institute, Rapid prototyping fabrication of the scaffold was conducted in Guangdong Longchuangyu Limited Cooperation. The scaffold was fabricated by sterophotocureable technology, and was made of photosensitized resin. METHODS： This experiment was carried out at the Center of Department of Traumatic Orthopedics. General Hospital of Guangzhou Military Area Command of Chinese PLA from October 2004 and January 2005, According to reverse engineering, layered image information of skeleton of the patients was scanned with CT/MRI, Anatomical models of region of interesting were created by means of CT or MRI three-dimensional reconstruction and surface reconstruction. The internal construction of the scaffolds was designed with CAD software in the outline of the anatomical models todevelop computer-aided model. The prototypes of the scaffolds were fabricated by RP process. MAIN OUTCOME MEASURES： ①CT/MRI scanning, three-dimensional reconstruction, anatomical modeling; ② computer-aided design of customized bone tissue engineering scaffolds; ③rapid prototyping fabrication of customized bone tissue engineering scaffold. RESULTS： ①Anatomical models of bone joint were established through CT/MRI three-dimensional reconstruction, ② The internal structure of the scaffold was designed to establish the entity model of bone tissue engineering scaffold successfully with computer-aided design software. ③ CAD model of bone tissue engineering scaffold guided prototypes to develop the customized anatomical-shaped bone tissue engineering scaffolds. The internal structure of bone tissue engineering scaffold was fine and had high degree of porosity and pore interconnectivity. CONCLUSION： Customized anatomical-shaped bone tissue engineering scaffolds can be fabricated with reverse engineering and RP technology. Among all RP processes, stereophotocureable technology （SLA） is the best one with good precision, smooth surface and good shaping.