Lin Hung-Pin, Tu Han-Ping, Hsieh Yu-Ping, Lee Bor-Shiunn
Department of Dentistry, MacKay Memorial Hospital.
Department of Dentistry, School of Dentistry, National Taiwan University.
Int J Nanomedicine. 2017 Jul 31;12:5473-5485. doi: 10.2147/IJN.S138410. eCollection 2017.
Statin at appropriate concentrations has been shown to induce odontoblastic differentiation, dentinogenesis, and angiogenesis. However, using a carrier to control statin release might reduce toxicity and enhance its therapeutic effects. The aim of this study was to prepare poly(d,l-lactide--glycolide acid) (PLGA) nanoparticles that contain lovastatin for application in direct pulp capping. The PLGA-lovastatin particle size was determined using dynamic light scattering measurements and transmission electron microscopy. In addition, the release of lovastatin was quantified using a UV-Vis spectrophotometer. The cytotoxicity and alkaline phosphatase (ALP) activity of PLGA-lovastatin nanoparticles on human dental pulp cells were investigated. Moreover, a real-time polymerase chain reaction (PCR) assay, Western blot analysis, and an enzyme-linked immunosorbent assay (ELISA) were used to examine the osteogenesis gene and protein expression of dentin sialophosphoprotein (DSPP), dentin matrix acidic phosphoprotein 1 (DMP1), and osteocalcin (OCN). Finally, PLGA-lovastatin nanoparticles and mineral trioxide aggregate (MTA) were compared as direct pulp capping materials in Wistar rat teeth. The results showed that the median diameter of PLGA-lovastatin nanoparticles was 174.8 nm and the cumulative lovastatin release was 92% at the 44th day. PLGA-lovastatin nanoparticles demonstrated considerably a lower cytotoxicity than free lovastatin at 5, 9, and 13 days of culture. For ALP activity, the ALP amount of PLGA-lovastatin (100 μg/mL) was significantly higher than that of the other groups for 9 and 13 days of culture. The real-time PCR assay, Western blot analysis, and ELISA assay showed that PLGA-lovastatin (100 μg/mL) induced the highest mRNA and protein expression of DSPP, DMP1, and OCN in pulp cells. Histological evaluation of the animal studies revealed that MTA was superior to the PLGA-lovastatin in stimulating the formation of tubular dentin in an observation period of 2 weeks. However, in an observation period of 4 weeks, it was evident that the PLGA-lovastatin and MTA were competitive in the formation of tubular reparative dentin and a complete dentinal bridge.
已表明适当浓度的他汀类药物可诱导成牙本质细胞分化、牙本质形成和血管生成。然而，使用载体来控制他汀类药物的释放可能会降低毒性并增强其治疗效果。本研究的目的是制备含有洛伐他汀的聚（d，l-丙交酯-乙交酯酸）（PLGA）纳米颗粒，用于直接盖髓术。使用动态光散射测量和透射电子显微镜测定PLGA-洛伐他汀的粒径。此外，使用紫外可见分光光度计对洛伐他汀的释放进行定量。研究了PLGA-洛伐他汀纳米颗粒对人牙髓细胞的细胞毒性和碱性磷酸酶（ALP）活性。此外，使用实时聚合酶链反应（PCR）分析、蛋白质印迹分析和酶联免疫吸附测定（ELISA）来检测牙本质涎磷蛋白（DSPP）、牙本质基质酸性磷酸蛋白1（DMP1）和骨钙素（OCN）的成骨基因和蛋白表达。最后，在Wistar大鼠牙齿中比较了PLGA-洛伐他汀纳米颗粒和矿物三氧化物凝聚体（MTA）作为直接盖髓材料。结果表明，PLGA-洛伐他汀纳米颗粒的中位直径为174.8nm，在第44天时洛伐他汀的累积释放率为92%。在培养5、9和13天时，PLGA-洛伐他汀纳米颗粒的细胞毒性明显低于游离洛伐他汀。对于ALP活性，在培养9和13天时，PLGA-洛伐他汀（100μg/mL）的ALP量显著高于其他组。实时PCR分析、蛋白质印迹分析和ELISA分析表明，PLGA-洛伐他汀（100μg/mL）在牙髓细胞中诱导DSPP、DMP1和OCN的mRNA和蛋白表达最高。动物研究的组织学评估显示，在2周的观察期内，MTA在刺激管状牙本质形成方面优于PLGA-洛伐他汀。然而，在4周的观察期内，很明显PLGA-洛伐他汀和MTA在管状修复性牙本质和完整牙本质桥的形成方面具有竞争力。
