結合創新型神經導管與大面積低功率雷射光治療對於截斷大鼠坐骨神經之神經再生影響評估

Effects of a novel nerve conduit combined with a large-area irradiation of low-level laser phototherapy on neural regeneration of the transected sciatic nerve in rats

李憶妤(Yi-Yu Lee)

指導教授 ： 劉百栓

中臺科技大學/健康科學院/醫學影像暨放射科學系暨研究所/碩士(2012年)

https://doi.org/10.6822/CTUST.2012.00053

摘要

本研究開發了一種新的可生物降解性的神經導管，此神經導管是具可吸收性的天然高分子材料--明膠（Gelatin）作為神經接合導管基材。將明膠並添加三鈣磷酸鹽（TCP）以強化神經導管的機械強度；最後將此神經接合導管浸泡於交聯劑—1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)溶液中，使其與明膠產生交聯反應，以減緩神經接合導管的降解速率（簡稱EGT神經導管）。在本篇研究中，將EGT神經導管植入神經受損的大鼠體內中結合大面積低功率雷射，波長為660 nm及功率為50 mW，其雷射探頭組成由鋁鎵銦磷組成之二極體雷射照射，治療一長斷端1.5公分的神經受損的研究。
EGT神經導管可以觀察到神經導管皆呈現完整的中空同心圓狀，外觀則較粗糙、顏色接近象牙白。吸水率測試試驗顯示了EGT神經導管有較高的穩定性，並不會因為管壁吸水而造成導管崩解或塌陷。在本篇研究中，關於體外酶降解試驗中，EGT導管增加了結構穩定度。其結果顯示了使用EDC交聯明膠基質並且添加三鈣磷酸鹽陶瓷粉末其機械強度可以提供一神經通道足以作為神經導管。將大鼠隨機放入下列三組：EGT/Sham、EGT/Laser、Autografts。隨機分別放入：EGT/Sham、EGT/Laser、Autografts。其中EGT/Sham組為將坐骨神經切斷後縫合EGT神經導管，且接受模擬照射低功率雷射組；EGT/Laser組為將坐骨神經切斷後縫合EGT神經導管並且接受大面積低功率雷射治療組；Autografts組為自體移植對照組，將動物的坐骨神經切斷後，立即將神經的近端與遠端縫合。EGT/Laser組立即以大面積低功率雷射照射治療，術後第一天傷口尚未縫合前進行雷射照射30分鐘，第二天起連續照射9天，每日照射5分鐘，而EGT/Sham組與EGT/Laser組使用相同方式照射大面積雷射，但大面積雷射刺激探頭則為關閉狀態。
神經導管植入大鼠體內12週後，EGT/Laser組與Autografts組之坐骨神經功能指數(P < 0.05)皆高於EGT/sham組。電生理測量方面，EGT/Laser組與Autografts組之複合肌肉電位(CAMP)的平均峰值與波下面積值皆顯著高於EGT/Sham組(P < 0.05)。與EGT/Sham組相比之下，EGT/Laser組和Autografts組明顯可以減少肌肉萎縮。組織形態學評估顯示，EGT/Laser組和Autografts組的神經再生比EGT/Sham更為快速，而雷射治療組表明雷射可以加速神經再生、刺激軸突發芽與繁殖並使髓鞘的厚度，比無治療雷射組修復的更為良好。本篇研究結果表明了周邊神經的損傷利用大面積低功率雷射治療結合EGT神經導管可以改善運動功能，增強電生理反應，減少肌肉萎縮，及加速神經的再生與修復。

關鍵字

機械強度 ； 大面積低功率雷射 ； 周邊神經修復 ； 神經接合導管 ； 生物降解

並列摘要

This paper proposes a novel biodegradable nerve conduit comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin, annexed with β-tricalcium phosphate (TCP) ceramic particles (EDC-Gelatin-TCP, EGT). In this study the EGT-implant site in rats was irradiated using a large-area 660 nm aluminum-gallium-indium phosphide (AlGaInP) diode laser (50 mW) to investigate the feasibility of laser stimulation in the regeneration of a 15-mm transected sciatic nerve.
The proposed EGT conduit has a cylindrical shape, ivory-like color, and a rough, compact outer surface. A water uptake test indicates that the unique properties of EGT noticeably increase the stability of the artificial nerve graft in water; and the hydrated conduit does not collapse or stenose. The cross-linked structure of the EGT conduit resists enzymatic hydrolysis, which led to improved structural properties in studies on in vitro degradation. Results show that the adherence of TCP ceramic particles to the EDC-cross-linked gelatin matrix provided a framework with mechanical strength sufficient to serve as a nerve conduit. The animals were divided into three groups: a sham-irradiated group (EGT/Sham); an experimental group undergoing low-level laser (LLL) therapy (EGT/Laser); a control group undergoing autologous nerve grafts (autografts). LLL therapy was applied for 30 min immediately following surgery, focusing on the area of nerve damage. The surgical site was then treated transcutaneously for 5 min daily for 9 consecutive days.
Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (SFI) (P < 0.05) and improved toe spreading development in the EGT/Laser and autograft groups than in the EGT/Sham group. In electrophysiological measurement, both the mean peak amplitude and the area under the compound muscle action potential (CMAP) curves in the EGT/Laser and autograft groups showed significantly improved functional recovery than the EGT/Sham group (P < 0.05). Compared with the EGT/Sham group, the EGT/Laser and autograft groups displayed a reduction in muscular atrophy. Histomorphometric assessments revealed that the EGT/Laser group had undergone more rapid nerve regeneration than the EGT/Sham group. The laser-treated group also presented greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the laser treatment, indicating improved nerve regeneration.
Thus, motor function, electrophysiologic reaction, muscular reinnervation, and histomorphometric assessments demonstrate that LLL therapy can accelerate the repair of a transected peripheral nerve in rats after being bridged with EGT conduit.

並列關鍵字

peripheral nerve injury ； neural regeneration ； Low-level laser therapy ； sciatic nerve

參考文獻

1. Inserra MM, Bloch DA, Terris DJ. Functional indices for sciatic, peronal, and posterior tibial nerve lesions in the mouse. Microsurgery 1998; 18:119-124.

2. Rochkind S, Nissan M, Alon M, Shamir M, Salame K. Effects of laser irradiation on the spinal cord for the regeneration of crushed peripheral nerve in rats. Lasers Surg Med 2001; 28:216-219.

3. Rochkind S, Quaknine GE. New trend in neuroscience: low-power laser effect on peripheral and central nervous system (basic science, preclinical and clinical studies). Neurol Res 1992; 14:2-11.

4. Rodriguez FJ, Valero-Cabré A, Navarro X. Regeneration and functional recovery following peripheral nerve injury. Drug Discov Today Dis Models 2004; 1:177-185.

5. IJkema-Paassen J, Jansen K, Gramsbergen A, Meek MF. Transection of peripheral nerves, bridging strategies and effect evaluation. Biomaterials 2004; 25:1583-1592.