Sugano M, Negishi Y, Endo-Takahashi Y, Hamano N, Usui M, Suzuki R, Maruyama K, Aramaki Y, Yamamoto M
Department of Periodontology, Showa University School of Dentistry, Tokyo, Japan; Department of Drug Delivery and Molecular Biopharmaceutics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan.
J Periodontal Res. 2014 Jun;49(3):398-404. doi: 10.1111/jre.12119. Epub 2013 Jul 24.
Periodontitis is the most common inflammatory disease caused by oral biofilm infection. For efficient periodontal treatment, it is important to enhance the outcome of existing regenerative therapies. The physical action of an ultrasound may be able to deliver a therapeutic gene or drugs into the local area of the periodontium being treated for periodontal regeneration. Previously, we developed "Bubble liposomes" as a useful carrier for gene or drug delivery, and reported that delivery efficiency was increased with high-frequency ultrasound in vitro and in vivo. Hence, the aim of the present study was to examine the possibility of delivering genes into gingival tissues using Bubble liposomes and ultrasound.
We attempted to deliver naked plasmid DNA encoding luciferase or enhanced green fluorescent protein (EGFP) into the lower labial gingiva of Wistar rats using Bubble liposomes, with or without ultrasound exposure. Ultrasound parameters were optimized for intensity (0-4.0 W/cm(2) ) and exposure time (0-120 s) to establish the most efficient conditions for exposure. The efficacy and duration of gene expression in the gingiva were investigated using a luciferase assay and fluorescence microscopy.
The strongest relative luciferase activity was observed when rats were treated under the following ultrasound conditions: 2.0 W/cm(2) intensity and 30 s of exposure time. Relative luciferase activity, 1 d after gene delivery, was significantly higher in gingiva treated using Bubble liposomes and ultrasound than in gingiva of the other treatment groups. Histological analysis also showed that distinct EGFP-expressing cells were observed in transfected gingiva when rats were treated under optimized conditions.
From these results, the combination of Bubble liposomes and ultrasound provides an efficient technique for delivering plasmid DNA into the gingiva. This technique can be applied for the delivery of a variety of therapeutic molecules into target tissue, and may serve as a useful treatment strategy for periodontitis.
牙周炎是由口腔生物膜感染引起的最常见的炎症性疾病。为了实现有效的牙周治疗，提高现有再生疗法的效果至关重要。超声的物理作用或许能够将治疗性基因或药物输送到接受牙周再生治疗的牙周局部区域。此前，我们开发了“气泡脂质体”作为一种用于基因或药物递送的有效载体，并报道在体外和体内高频超声可提高递送效率。因此，本研究的目的是探讨使用气泡脂质体和超声将基因递送至牙龈组织的可能性。
我们尝试使用气泡脂质体，在有或无超声照射的情况下，将编码荧光素酶或增强型绿色荧光蛋白（EGFP）的裸质粒DNA递送至Wistar大鼠的下唇牙龈。对超声参数的强度（0 - 4.0 W/cm²）和照射时间（0 - 120秒）进行优化，以确定最有效的照射条件。使用荧光素酶测定和荧光显微镜研究牙龈中基因表达的效率和持续时间。
在以下超声条件下处理大鼠时观察到最强的相对荧光素酶活性：强度为2.0 W/cm²，照射时间为30秒。基因递送1天后，使用气泡脂质体和超声处理的牙龈中的相对荧光素酶活性显著高于其他处理组的牙龈。组织学分析还表明，在优化条件下处理大鼠时，在转染的牙龈中观察到明显表达EGFP的细胞。
基于这些结果，气泡脂质体和超声的组合提供了一种将质粒DNA有效递送至牙龈的技术。该技术可应用于将多种治疗性分子递送至靶组织，并可能成为牙周炎的一种有效治疗策略。
