摘要
在体外构建外形逼真、机械强度可调节的个性化耳廓软骨支架,是组织工程方法修复外耳耳廓缺损的重要方向之一。针对这一研究目的,采用基于快速成形原理的熔融挤出成形方法,使用颗粒状聚氨酯生物材料,通过搭建试验平台,设计一系列工艺因素对成形过程及支架力学性能的影响试验,研究制造耳廓软骨支架的最优工艺参数范围。试验发现:喷头温度影响材料挤出稳定性和弹性;成形室温度影响结构整齐度和层间结合度;送料速度和扫描速度,与挤出速度的匹配关系,影响出丝的均匀度和成形过程的稳定性;不同扫描速度的喷头所形成的温度场分布,影响已成形结构的弹性;成形过程存在最小局部反复造型面积;温度以及CLI数字模型离散处理参数,影响支架力学性能。结果表明,熔融挤出成形方法制备的聚氨酯材料耳廓软骨支架,不仅可以实现逼真的耳廓外形,还可通过控制各种工艺参数,得到接近天然耳廓的力学强度,以满足临床中不同病患的个性化需求。
In vitro constructing of a personalized auricle cartilage scaffold with lifelike appearance and adjustable mechanical strength, is an important method in tissue engineering to repair the auricle defect. Aiming at this, the melted extrusion forming technique based on the rapid prototyping principle is adopted, particle polyurethane biomaterial is used, and an experiment platform is built up. Then a series of experiments are carded out to study the effects of technical factors on forming process and scaffold mechanical properties, in order to find out the best parameter range for manufacturing the auricle cartilage scaffold. It is found that nozzle temperature has an impact on extrusion stability and material flexibility; forming room temperature affects the structure uniformity and interlayer integrity; feed speed and scanning speed should match extrusion speed, to maintain the strand uniformity and the forming stability; nozzle scanning with different speeds results in different temperature fields, which also affects the flexibility of formed structure; there exists a minimum local forming; temperature and the discrete processing parameters of CLI mathematical model affect the mechanical properties of the formed scaffold. Therefore, based on the melted extrusion forming technique, suitable polyurethane auricle cartilage scaffold can be constructed to fulfill the personalized demand of different patients, not only with exact lifelike appearance, but also with proper mechanical properties close to the natural auricle cartilage.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第5期139-144,共6页
Journal of Mechanical Engineering
关键词
聚氨酯
耳廓软骨
支架
快速成形
熔融挤出成形
Polyurethane Auricle cartilage Scaffold Rapid prototyping Melted extrusion forming
