可吸收内固定器件的制备及研究

发布时间：2018-10-04 21:03

【摘要】：临床上用于治疗骨折和骨缺损的各种内固定器件多为金属材料,但是金属材料存在许多不足,尤其是需要二次手术取出,给病人带来痛苦。因此用可降解高分子材料代替金属材料代表了内固定器件的发展方向。但是植入后产生的无菌性炎症反应、力学强度不理想、以及内固定器件加工困难成为阻碍其临床应用的瓶颈问题。针对上述问题,本文选择聚左旋乳酸/纳米羟基磷灰石(PLLA/nHAP)复合材料作为内固定材料,利用中型反应釜规模化制备纳米羟基磷灰石(nHAP),并通过表面接枝和表面改性两种途径,分别制备了聚左旋乳酸接枝纳米羟基磷灰石(PLLA-g-nHAP)相容剂和硅烷化羟基磷灰石M-nHAP,并对其进行了表征。经改性后,nHAP的分散性以及与PLLA复合后的界面相容性得到改善。力学测试表明经硅烷偶联剂表面改性后,复合材料的力学性能有较大的提高,最高弯曲强度可以达到128.43MPa,最高弯曲模量可以达到3.61GPa。 PLLA加工温度接近分解温度,常规加工方法很容易导致分子量下降,影响使用性能。本研究中利用混合和注塑两种加工方法的结合,自行设计加工设备,制备出内固定骨螺钉。为解决形状复杂的制品难以测定力学性能的问题,本文尝试采用有限元分析的方法来分析骨螺钉的使用情况。通过建立模型,预测得出在150N的剪切力下PLLA/M-nHAP(20w%)复合原料制备的骨内固定螺钉在人体内是可用的。
[Abstract]:Most of the internal fixation devices used in the treatment of fracture and bone defect are metal materials, but there are many shortcomings in metal materials, especially in the need of secondary surgical removal, which brings pain to the patients. Therefore, the use of degradable polymer instead of metal represents the development direction of internal fixation devices. However, the aseptic inflammatory reaction after implantation, the poor mechanical strength and the difficulty in processing internal fixation devices are the bottleneck problems that hinder its clinical application. In order to solve the above problems, poly (L-lactic acid) / nano-hydroxyapatite (PLLA/nHAP) composite was selected as the internal fixation material. Nano-hydroxyapatite (nHAP), was prepared on a large scale in a medium reactor, and surface grafting and surface modification were used to prepare nano-hydroxyapatite (nHAP),. Poly (L-lactic acid) grafted nano-hydroxyapatite (PLLA-g-nHAP) and silanized hydroxyapatite (M-nHAPs) were prepared and characterized. The dispersion of modified nHAP and the interfacial compatibility with PLLA were improved. The mechanical tests show that the mechanical properties of the composites can be greatly improved by surface modification of silane coupling agent. The maximum bending strength and modulus of the composites can reach 128.43 MPA and 3.61 GPA respectively. The processing temperature of PLLA is close to the decomposition temperature, and the conventional processing method can easily lead to the decrease of molecular weight and affect the performance of the process. In this study, the internal fixation screw was prepared by using the combination of mixing and injection molding. In order to solve the problem that it is difficult to measure the mechanical properties of products with complicated shape, this paper attempts to use finite element analysis method to analyze the use of bone screws. By establishing the model, it is predicted that the PLLA/M-nHAP (20w%) composite screw can be used in human body under the shear stress of 150N.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.6

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