生物可降解性控制四環黴素和洛伐他汀釋放之奈米微粒 在促進牙周缺損修復之應用: 動物實驗

Controlled-release of tetracycline and lovastatin by PLGA-chitosan nanoparticles enhances osteogenesis in a periodontal defect: Animal Study

李建成(Chein-Chen Lee)

指導教授 ： 陳漪紋

國立臺灣大學/醫學院/臨床牙醫學研究所/碩士(2016年)

https://doi.org/10.6342/NTU201601185

摘要

洛伐他汀(lovasatin)為一種HMG-CoA還原酶的抑製劑,此催化作用受阻可 以有效降低體內膽固醇的合成的。因此此類藥物已被廣泛用來降低膽固醇、治療 高脂血症和預防心血管疾病。近年來,已經有學者報告洛伐他汀(lovasatin)做為 宿主免疫調節劑,於慢性牙周炎的治療效果。四環黴素為一種廣效性的抗生素, 當它使用於subantimicrobial低劑量時,可以抑制基質金屬蛋白酶(matrix metalloproteinases, MMPs),此蛋白酶在牙周組織的破壞過程扮演重要角色。在本 次研究中,透過“雙重乳化”技術製備出可以控制四環黴素和洛伐他汀釋放之生物可 降解性奈米顆粒,其對慢性牙周炎的治療具輔助性效果。本次動物實驗的目的是 在研究此生物可降解性奈米顆粒的生物相容性以及對於牙周組織再生的效果。
本實驗係使用 6 隻一歲大的米格魯,體重介於 7 公斤到 10 公斤。分別將其上 顎兩側之第三門齒拔除,經過五週的癒合時間以後。以手術的方式於上顎兩側犬 齒近心側的無牙脊製備好一固定大小,長寬高分別為 4x5x5 釐米的三壁骨內缺損, 確定其牙根表面的骨頭完全移除,牙根已裸露後,一共分成 2 組。實驗組包含六隻狗(n=6),缺損內使用四環黴素和洛伐他汀釋放之生物可降解性奈米顆粒;對照 組也包含六隻狗(n=6)的缺損內則沒有放置任何材料。實驗動物在術前,術後以及 犧牲前會接受錐形電腦斷層檢查(cone beam CT)。經過 8 週的癒合期,將動物犧牲 後,標本用放射線影像以及高解析斷層掃描分析齒槽骨新生程度,再以組織切片判讀觀察牙周附連組織再生的程度。

關鍵字

牙周缺損再生 ； 洛伐他汀 ； 奈米微粒 ； 動物實驗 ； 微電腦斷層

並列摘要

Chronic periodontitis is characterized by inflammation of periodontal tissues, leading to bone resorption and tooth loss. The goal of treatment is to regenerate periodontal tissues including bone and cementum as a consequence of disease. Statin(levostatin), an inhibitor of HMG-CoA reductase, has been used as an anti hyperlipidemic agent to prevent cardiovascular disease for years. Previous studies suggested that lovastatin has a significant role in new bone formation; therefore, the local delivery of lovastatin might enhance its therapeutic effects. The local delivery of tetracycline was proven to be effective in controlling localized periodontal infection without apparent side effects. With a subantimicrobial dosage, tetracycline was regarded as an inhibitor of matrix metalloproteinases(MMPs) which play an important role in periodontal destruction. A number of local delivery devices have been developed recently, including poly(D,L-lactide-co-glycolide acid) (PLGA) nanoparticles.
In this study, the biodegradable nanoparticles was prepared through “double emulsion” technique with controlled release of tetracycline and lovastatin as an adjunctive therapy of periodontitis. The aim of this animal study was to investigate the effect of the biodegradable nanoparticles in periodontal tissue regeneration.
6 healthy 1-year-old beagle dogs had their I2, I3 extracted before the experiment. After 8 weeks of uneventful healing period, 4x5x5mm three-wall intrabony defect was created at the mesial side of the upper canine. In experiment group, the defect was filled with gelatin gel containing PLGA-chitosan-lovastatin-tetracycline(0.3%) nanoparticles; whereas no material was placed in control group. Cone-beam CT was taken at pre-surgery, immediate after surgery and before sacrifice. MicroCT assessment of the enbloc specimen was analyzed and histology was studied. . The results show that healing in all surgical sites progressed normally without any complication or exposure of material in either experiment or control group. The volumetric analysis from Micro-CT revealed significantly increased new bone formation in defects filled with nanoparticles in dogs. Also, PLGA-chitosan-lovastatin-tetracycline(0.3%) nanoparticles
was completely replaced by new bone. Histometric analysis shows there were no apperant inflammatory response or foreign body reaction in the experimental group. Additionaly, new bone, new cementum, and new connective tissue attachment were significantly enhanced in experimental sites. This pilot study shows that the PLGA-chitosan-lovastatin-tetracyclin (0.3%) nanoparticles has high biocompatibility and may potentially enhance periodontal tissue regeneration in three wall defects in dogs. This novel local delivery device might be useful as an adjunctive treatment in periodontal regenerative therapy.

並列關鍵字

PLGA-chitosan-lovastatin-tetracyclin nanoparticles ； chronic periodontitis ； animal study ； MicroCT

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