利用積層製造之鐵磁性聚乳酸複合材料骨釘對於促進骨再生之效果

The Bone Regeneration Effect of 3D Printed Ferromagnetic Magnetite-based Polylactide Composite Bone Screw

曾知雋(Jy-Jiunn Tzeng)

指導教授 ： 黃豪銘

臺北醫學大學/口腔醫學院/生醫材料暨組織工程研究所/碩士(2014年)

摘要

追求傷患部的加速復元是永無止盡的課題，促進骨缺損部位的加速修復更是生醫材料與組織工程領域的重點研究之一。本研究以具可充磁特性之聚乳酸複合材料，配合射出成形及積層製造方法製做骨釘，並以實驗動物模式評估其促進骨復元的效果。此外，由於過去的研究發現植體表面微細螺紋（Micro-thread）結構有助於促進骨生長，因此在本實驗中，我們利用前述材料以積層製造法製作骨釘，並評估其層狀堆積時，於產物表面自然形成的沉積紋路對骨再生的影響。在材料方面，本研究利用具有可磁化及具生物相容性之含有20wt%四氧化三鐵的聚乳酸為材料，以含0wt%四氧化三鐵的聚乳酸材料為對照組，製成骨釘。在實驗方法上，於骨釘製作完成之後，首先對四氧化三鐵聚乳酸複合材料進行磁性檢測，確認其確能隨著四氧化三鐵含量的增加，提供較高的靜磁場。接著進行材料性質檢測實驗，以瞭解射出成形之骨釘與積層製造骨釘，在成份上含有與不含四氧化三鐵時，其物理性質與促進顯影效果上的差異，並以有限元素分析結果觀察微細螺紋結構的有無其應力分佈的情形。經由本研究計劃之動物實驗，觀察混有鐵磁性奈米粒子之聚乳酸骨釘能提供靜磁場刺激源，且對促進骨修復具有的正面效果，並同時有效地增進電腦斷層掃描時的顯影性。

關鍵字

加法製造 ； 四氧化三鐵奈米粒子 ； 聚乳酸 ； 骨再生

並列摘要

To accelerate the patient’s recovery is one of the main targets in biomaterial and tissue engineering field. Thus, to encourage the bone healing is definitely important. In the past, researchers found that under the static magnetic field, the bone could heal faster. Polylactide is a biodegradable material that used in bone screws and overcomes the shortcoming of traditional metal materials, but this material is hard to observe with the computed tomography. The ferromagnetic particle under the nano size could be biocompatible, non-toxic and radiopaque. Based on these, we combine the ferromagnetic particle with polylactide and make it into composite. This material can be degraded and metabolized by human body.
Additive manufacturing (also known as 3D-printing, rapid prototyping) has substantial progress in recent years, and has been widely spread to many fields. Scientists noticed the high accuracy and low limitation of additive manufacturing can be appropriate used in medicine. For example, it can be used to mimic human tissues or organs, to create the scaffold for cell growth, or even to build prosthetics to replace malfunctioning body parts.
In this research, we adopt the 3D-printing technique to produce the biodegradable bone screws with the magnetite-based polylactide composite. In the bone screw strength test, we find the screws produced by 3D-printer are weaker than the screws made by injection molding. The screws made with pure polylactide are stronger than the screws which contained ferromagnetic particles. In animal study, we find the implant side with screws that contain ferromagnetic particles has more regenerated bone volume. The static magnetite field from the ferromagnetic nano particles within the polylactide plays an important role in the promotion of bone healing process.
　　Although the bone screws fabricated by injection molding are stronger than the 3D-printed screws, the 3D-printed screws still have its advantage, such as more adjustability and lower cost for a small amount of production. From the animal study, we confirm the affection of different materials on the healing process.

並列關鍵字

Additive Manufacturing ； Fe3O4 nona-particle ； Polylactide ； Bone Regeneration

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