hbFGF基因及hBMP-7基因修饰的组织工程化复合物联合应用促进牙槽骨再生动物实验研究

目的 观察人碱性成纤维细胞生长因子(hbFGF)基因及人骨形成蛋白-7(hBMP-7)基因修饰的组织工程化复合物联合应用对牙槽骨缺损再生的影响.方法 利用hbFGF基因转染Beagle犬牙龈成纤维细胞(GFs),并将其接种于脱细胞真皮基质(ADM)形成组织工程化复合物,同时以hBMP-7基因转染Beagle犬骨髓基质细胞(BMSCs),将其与胶原膜BME-10X复合,共同植入Beagle犬的人工牙周组织缺损区,通过组织学观察和测量分析,评价其对牙槽骨再生的影响.结果 术后6、12周,光镜下观察可见转染GFs复合ADM组和未转染GFs复合ADM组均较单纯BMSCs复合BME-10X组有更多的新生牙槽骨、新生牙周膜和新生牙骨质样组织生长;术后12周各组相对于术后6周的各组有更多的新生牙槽骨、新生牙周膜和新生牙骨质样组织.新生牙骨质与新生牙槽骨测量显示,转染hbFGF的GFs/ADM复合物的联合应用能显著提高hBMP-7基因修饰的组织工程化复合物修复牙周组织缺损的程度.结论 转染bFGF的GFs/ADM复合物有助于促进hBMP-7基因修饰的组织工程化复合物对牙周组织缺损的修复.     

新型多孔磷酸钙支架对骨髓间充质干细胞生物学行为的影响

目的评价新型多孔磷酸钙（CPC）作为骨组织工程支架对Beagle犬骨髓间充质干细胞（BMSCs）黏附、增殖及成骨分化等生物学行为的影响。方法将Beagle犬BMSCs接种于新型多孔CPC三维支架表面,以磷酸三钙（TCP）和聚乳酸-聚羟基乙酸共聚物（PLGA）为对照组,通过观察细胞形态、绘制细胞生长曲线、测定碱性磷酸酶（ALP）活性、进行茜素红染色并半定量测定骨钙素等方法,检测BMSCs在支架材料上的黏附、增殖及成骨分化情况。结果细胞形态和生长曲线结果显示BMSCs在新型多孔CPC三维支架材料表面分布均匀,生长及增殖活跃。ALP活性半定量结果表明,CPC、TCP组ALP表达强度明显高于PLGA组（P＜0.05）,CPC组与TCP组间的差异无统计学意义（P＞0.05）。骨钙素染色与半定量检测结果均显示：各观察点PLGA组钙盐沉积量明显少于CPC和TCP组（P＜0.05）,而TCP和CPC组间的差异无统计学意义（P＞0.05）。结论本实验所用多孔CPC材料具有与TCP类似但优于PLGA的良好生物相容性,利于BMSCs的黏附、增殖及成骨分化,可作为支架材料与BMSCs共同培养,构建具有成骨能力的组织工程化骨。     

中文文摘

1．骨保护素基因修饰联合细胞移植技术促进牙周组织再生的实验研究／周巍…／／华西口腔医学杂志．-2010，28（3）．-324～329 将真核分泌表达穿梭载体pSecTag2／B—opg瞬时转染第3代自体犬BMSCs后，采用免疫化学和Western blot的方法检测OPG蛋白的表达，倒置相差显微镜和扫描电镜观察转染后的BMSCsOPG在聚乳酸一羟基乙酸共聚物（PLGA）支架上的黏附、聚集情况。     

BMSCs复合PRF修复牙槽骨缺损中OPG和RANKL的表达及意义

目的：探讨骨髓间充质干细胞（BMSCs）复合富血小板纤维蛋白（PRF）修复牙槽骨缺损中骨保护素（OPG）和核因子B受体活化因子配体（RANKL）的表达及意义。方法：取健康雄性2月龄新西兰兔36只,随机分为A、B、C、D 4组,均在全麻下微创拔除下颌左侧中切牙。 A组植入BMSCs与PRF复合物,B组植入PRF,C组植入BMSCs,D组为空白对照组。按术后4,8,12周3个时间点（每个时间点9只）处死动物并立即于骨缺损部位取材,免疫组织化学方法检测OPG和RANKL的表达。结果：4,8,12周时A组、B组、C组OPG的表达高于D组（P＜0．05）;4,8,12周时A组、B组、C组RANKL的表达高于D组（P＜0．05）;析因分析显示自体BMSCs复合PRF修复牙槽骨缺损中OPG,RANKL的表达高于单独使用BMSCs或PRF（P＜0．05）。结论：自体BMSCs复合PRF修复牙槽骨缺损会增加OPG,RANKL的表达,有助于牙槽骨改建。     

新型多孔磷酸钙复合骨髓基质干细胞组织工程实验研究

目的观察新型生物材料多孔磷酸钙的生物相容性及复合骨髓基质干细胞（BMSCs）异位成骨情况。方法体外培养第2代Beagle犬BMSCs,转染绿色荧光蛋白（GFP）后与多孔磷酸钙（CPC）复合培养,获得最佳复合浓度,倒置和荧光显微镜、扫描电镜下观察BMSCs黏附和生长情况,复合体植入裸鼠皮下8周观察异位成骨。结果BMSCs转染GFP与多孔CPC复合培养1 d,细胞从材料中爬出,形态正常,7 d可见细胞伸出伪足,分泌基质;复合体可异位成骨。结论多孔CPC生物相容性好,是一种较理想的骨组织工程支架材料。     

应用细胞片层技术构建组织工程骨修复犬下颌骨缺损的实验研究

目的应用骨髓间充质干细胞（BMSCs）细胞片层构建组织工程骨修复犬下颌骨缺损,探讨细胞片层在成骨中的作用。方法采用密度梯度离心法分离和培养BMSCs,将BMSCs向成骨细胞诱导培养后,制备细胞片层。将细胞片层包裹到聚乳酸羟基乙酸共聚物（PLGA）支架表面,将其植入犬左侧下颌骨全层缺损中,对侧下颌骨植入无细胞片层包裹的支架复合体作同体对照。将16只犬分为4组,每组4只。术后4、8、12、16周分别处死1组,取材行大体及组织学观察。结果实验侧成骨好于对照侧,术后16周,实验侧骨缺损大部分被新生骨替代,舌侧形成与正常骨相似的密质骨,与正常骨断端骨性愈合。实验侧新生骨光密度值大于对照侧,两者差异有统计学意义（P<0.05）。实验侧可见较多哈弗氏系统及红骨髓,大量板层骨;对照侧哈弗氏系统较少。结论利用细胞片层技术可以构建出含板层骨结构的组织工程骨。     

人转化生长因子β1基因转染牙龈成纤维细胞促进牙周组织再生的动物实验

目的 评价人转化生长因子β1(human transform growth factor-β1,hTGF-β1)基因转染犬自体牙龈成纤维细胞(gingival fibroblast,GF)在治疗人工Ⅱ度根分叉骨缺损中作为组织工程种子细胞所发挥的作用.方法 将hTGF-β1基因转染后的犬自体GF作为组织工程种子细胞,与海螵蛸骨天然纳米羟基磷灰石(cuttlebone-transformed nanometer hydroxyapatite,CBHA)体外复合,制备犬下颌前磨牙区的Ⅱ度根分叉人工骨缺损模型,应用随机化完全区组设计方法将36颗犬前磨牙分为以下4组:①阴性对照组:不作任何处理直接缝合;②阳性对照组:置入牙周韧带细胞(periodontal ligament cell,PDLC)-CBHA复合物;③转染GF组:置入hTGF-β1基因转染犬GF-CBHA复合物;④未转染GF组:置入犬GF-CBHA复合物.每组9颗牙.对各组进行组织学观察和测量,并作示踪实验.结果 与阴性对照组比较,转染GF组、阳性对照组均可显著促进根分叉区牙周组织的再生(P＜0.01),两组的新生牙骨质高度(NC)、新生牙槽骨高度(NB)及新生结缔组织高度(NCT)分别为:(2.97±0.50)、(4.29±0.26)及(4.73±0.06)mm;(3.09±0.26)、(4.46±0.25)及(4.69±0.10)mm,且两组之间差异无统计学意义(P＞0.05).未转染GF组虽可促进牙槽骨再生[NB=(3.46±0.32)mm],但牙根有一定程度的吸收;示踪实验显示:转染后的GF在新生牙槽骨及牙周膜组织中均可发现.结论 hTGF-β1基因转染后的犬自体GF作为组织工程种子细胞,与CBHA体外复合后在人工Ⅱ度根分叉骨缺损的治疗中有显著的促牙周组织再牛的作用,参与了新牛牙槽骨及牙周膜的形成.     

转化生长因子-β1基因治疗对种植体周骨质疏松的影响

目的探讨转化生长因子- β1（TGF- β1）基因治疗对种植体周围骨质疏松和骨缺损的影响。方法构建pCDNA3.1（+）- TGF- β1真核表达载体，转染大鼠骨髓间充质干细胞（BMSCs），并与聚乳酸- 羟基乙酸（PLGA）体外黏附。制备骨质疏松大鼠股骨植入钛种植体模型，将24只Wister大鼠随机分为实验组、对照组和空白对照组，实验组为在种植体周骨缺损处植入TGF- β1基因修饰BMSCs复合PLGA；对照组为BMSCs复合PLGA。术后第4和8周取标本行免疫组化和组织学分析，观察种植体周骨组织中TGF- β1的表达和组织学变化。结果术后第4周，实验组骨缺损区的TGF- β1表达较对照组和空白对照组明显；第8周实验组骨缺损区被新生骨充填，骨质较对照组和空白对照组明显改善。结论TGF- β1基因修饰BMSCs体内回植后，可在种植体周围骨组织内表达TGF- β1，并可以影响种植体周骨缺损的修复和骨质疏松状况。     

犬骨髓间充质干细胞复合磷酸钙骨水泥修复骨缺损的实验研究

目的:评价骨髓间充质干细胞复合磷酸钙骨水泥支架材料修复下颌骨缺损的效果。方法:分离培养犬骨髓间充质干细胞(BMSCs)。成骨诱导培养14 d后,分别采用茜素红染色与碱性磷酸酶染色,观察其诱导效果。将细胞与磷酸钙骨水泥(CPC)支架材料复合,用于动物实验。在4只Beagle犬的下颌骨每侧制作3处大小一定的骨缺损。随机将骨缺损分为3组进行处理:BMSCs-CPC组(移植复合种子细胞的支架材料)、CPC组(只移植支架材料)和空白组(不做任何处理)。分别于移植后第4、8周处死2只犬,行大体、X线、骨缺损修复区组织形态观察与计量分析。采用SPSS 13.0软件包对数据进行统计学分析。结果:术后各组均有不同程度的骨再生。BMSCs-CPC组、CPC组中骨组织再生情况优于空白组。BMSCs-CPC组支架材料降解程度与新骨形成情况优于CPC组。术后第4、8周,BMSCs-CPC、CPC组新生骨面积百分比均显著高于空白对照组(P<0.05),BMSCs-CPC组新生骨面积百分比显著高于CPC组(P<0.01);BMSCs-CPC组中剩余支架材料面积百分比显著低于CPC组(P<0.01)。结论:BMSCs种子细胞复合CPC支架材料是一种有效的、促进新骨再生的骨缺损修复方法,有利于颌骨高度及宽度的保存。     

冻存骨髓基质细胞和胶原膜在裸鼠体内的成骨研究

目的：研究经超低温冻存后的骨髓基质细胞（bone marrow stromal cells,BMSCs）和支架材料胶原膜BME-10X复合体植入裸鼠体内的成骨情况.方法：体外分离培养Beagle犬 BMSCs,冻存二代生长状况良好的BMSCs.12个月后,复苏冻存的BMSCs,并在体外构建BMSCs和0.5 cm×0.5 cm大小的BME-10X复合体.将胶原膜＋BMSCs＋矿化诱导培养液、胶原膜＋BMSCs＋基础培养液、单纯胶原膜＋矿化诱导培养液培养5 d后,植入裸鼠体内,并于术后第4、8、12周取出标本,进行大体观察和组织病理学分析.结果：单纯胶原膜＋诱导培养液组在植入胶原膜后,胶原膜边界清晰,膜边缘及内部基本没有细胞生长;在胶原膜＋BMSCs＋基础培养液组,术后第4周可见,胶原膜内有细胞长入,并有细小的条索状新生胶原形成,随着时间的延长,支架胶原逐渐分解,新形成的条索状胶原纤维变粗大;在胶原膜＋BMSCs＋矿化诱导培养液组,植入后也可见支架胶原的分解和更多的细胞生长,大量新生的胶原形成类骨质样组织.结论：冻存BMSCs复苏后进行体外培养扩增与诱导分化,并在在体内环境下复合胶原支架材料,仍然具有较强成骨能力.     

Effect of autologous bone marrow stromal cells transduced with osteoprotegerin on periodontal bone regeneration in canine periodontal window defects

The purpose of this investigation was to evaluate the effect of osteoprotegerin (OPG)-modified autologous bone marrow stromal cells (BMSCsOPG) combined with guided tissue regeneration on bone regeneration of periodontal window defects. pSecTag/2B-OPG was transduced into BMSCs by Lipofectamine 2000. The expression of OPG protein in the BMSCs was detected by immunocytochemistry and Western blotting. Periodontal window defects (4 x 4 x 3 mm) were surgically created in the buccal aspect of the mandibular premolars and randomly assigned to receive BMSCsOPG-PLGA (cells + material + OPG), BMSCs-PLGA (cells + material), PLGA (material), or root planing only (negative control). The animals were euthanized at 6 weeks postsurgery for histologic analysis, and histologic measurements were then performed. Results showed that the height of new alveolar bone and cementum and the formation of new connective tissue were significantly greater in the experimental group than in the control groups after 6 weeks (P <.05), whereas there was no significant difference between the material control and negative control (P > .05). These findings suggest that delivery of BMSCsOPG-PLGA may be a viable approach to promote bone regeneration of periodontal bone defects.     

Participation of periodontal ligament cells with regeneration of alveolar bone

BACKGROUND: It is important to clarify the participation of periodontal ligament (PDL) cells in the regeneration of alveolar bone to establish a reliable approach for obtaining periodontal regeneration. The aim of this study was to determine whether PDL cells play an important role in alveolar bone repair during the course of periodontal regeneration. METHODS: In an in vitro study, the expression of the osteoblast phenotype, such as alkaline phosphatase activity and parathyroid hormone-dependent 3',5'-cyclic adenosine monophosphate accumulation, was investigated in dog PDL cells (DPLC) and dog bone cells isolated from mandibles (DBC). In a related study, the roots of mandibular third premolars extracted from aged dogs were divided into a PDL(+) group, in which the PDL was preserved, and a PDL(-) group, in which the PDL was removed. These roots were respectively transplanted into surgically created bone cavities with buccal and interproximal bone defects in an edentulous area, prepared in advance by extraction of mandibular fourth premolars. These bone defects with the transplanted roots were completely covered with submerged physical barrier membranes. New bone formation and new connective tissue attachment, which require new cementum and insertion of functionally oriented new collagen fibers of periodontal ligament, were histomorphometrically assessed, and were compared between the PDL(+) and PDL(-) groups 6 weeks after transplantation. RESULTS: Both cultured DPLC and DBC exhibited the osteoblast phenotype. New connective tissue attachment was observed only in the PDL(+) group. However, alveolar bone was almost completely regenerated to the original bone height in both the PDL(+) and PDL(-) groups, and the amount of newly formed bone was not significantly different between the 2 groups. CONCLUSIONS: DPLC retain the capability to differentiate into an osteoblast lineage and may act in the regeneration of periodontal ligament with new cementum formation, whereas these cells may have a limited influence on alveolar bone formation during the course of periodontal regeneration.     

复合膜引导牙周组织再生

目的：观察基因重组人骨形成蛋白-2、胶原、聚乳酸／聚羟基乙酸共聚体（rhBMP-2／Co／PLGA）复合膜引导牙周组织再生的效果。方法：在杂犬的第四前磨牙及第-磨牙颊侧部位,制备急性牙周组织缺损模型,将复合膜材料植入实验部位,设对侧为同体对照。术后8周处死动物,切取双侧下颌骨标本,行软x线照相和组织学观察。结果：实验侧可见大量新生牙槽骨、牙骨质和牙周膜纤维形成;对照侧主要是牙龈上皮和上皮下结缔组织增生。结论：rhBMP-2／Co／PLGA复合膜符合GTR的要求,能够引导牙周组织再生。     

A histopathologic investigation on the effects of electrical stimulation on periodontal tissue regeneration in experimental bony defects in dogs

BACKGROUND: One endpoint of periodontal therapy is to regenerate the structure lost due to periodontal disease. In the periodontium, gingival epithelium is regenerated by oral epithelium. Underlying connective tissue, periodontal ligament, bone, and cementum are derived from connective tissue. Primitive connective tissue cells may develop into osteoblasts and cementoblasts, which form bone and cementum. Several procedural advances may support these regenerations; however, the regeneration of alveolar bone does not always occur. Therefore, bone stimulating factors are a main topic for periodontal reconstructive research. The present study was designed to examine histopathologically whether the application of an electrical field could demonstrate enhanced alveolar and cementum regeneration and modify tissue factors. METHODS: Seven beagle dogs were used for this experiment. Mandibular left and right sides served as control and experimental sides, respectively, and 4-walled intrabony defects were created bilaterally between the third and fourth premolars. The experimental side was treated with a capacitively coupled electrical field (CCEF) (sinusoidal wave, 60 kHz, and 5 V peak-to-peak), applied for 14 hours per day. The following measurements were performed on the microphotographs: 1) the distance from the cemento-enamel junction to the apical notch (CEJ-AN) and from the crest of newly formed bone (alveolar ridge) to the apical notch (AR-AN); 2) the thickness of new cementum in the apical notch region; and 3) the length of junctional epithelium. The following histopathologic parameters were assessed by a semiquantitative subjective method: 1) inflammatory cell infiltration (ICI); 2) cellular activity of the periodontal ligament; 3) number and morphology of osteoclasts; 4) resorption lacunae; and 5) osteoblastic activity. RESULTS: The results showed that the quantity of new bone fill and the mean value of the thickness of the cementum were significantly higher for the experimental side (P < 0.01). The location of the base of the pocket was positioned more coronally with respect to the apical point of the coronal notch in the experimental side (statistically significant P < 0.01). The length of the junctional epithelium and the number of osteoclasts were higher in the stimulated side than the coronal side; these findings were also statistically significant (P < 0.01). The comparison of the electrically stimulated versus non-stimulated mandibles with the semiquantitative subjective method demonstrated statistically significant differences in defined histopathologic parameters, except for osteoclast morphologies (P > 0.05). CONCLUSIONS: This study demonstrated that the CCEF method has the potential to produce reconstructive effects and bone deposits. Further investigations with respect to the theoretical determination of local field parameters of the periodontal tissue complex, such as permittivity, conductivity, strength of the field electrical stimulation applied to the periodontal field current density, wavelength, and signal frequency appropriate for this field, should be undertaken. Using different electromotive forces alone or in combination with bone graft materials, guided tissue regeneration techniques, and dental implants may achieve a new dimension in periodontal therapy in the near future.     

环孢素A联合牙龈卟啉单胞菌脂多糖局部应用对大鼠牙周组织缺损修复影响研究

目的    探讨环孢素A（CsA）联合牙龈卟啉单胞菌脂多糖（P.g-LPS）局部应用对大鼠牙周组织缺损修复的影响。方法    　成功构建18只SD大鼠牙周急性缺损模型,随机均分为3组,分别在缺损对应口腔内局部注射生理盐水（对照组）、CsA 2 mg/kg（CsA组）或CsA 2 mg/kg+P.g-LPS 1μg （CsA+P.g-LPS组）,30 d后处死全部大鼠,切取双侧下颌骨制作标本切片,HE染色观察CsA单独应用及与低剂量P.g-LPS联合应用对大鼠牙周组织缺损修复的影响。结果    CsA 2 mg/kg单独及与低剂量P.g-LPS联合应用,对大鼠牙周组织缺损的修复均有一定促进作用,但与对照组相比,差异均无统计学意义（P > 0.05）。结论    在模拟人体牙周炎恢复期低毒素、微炎症状态的牙周情况下局部应用CsA,既不会促进微炎症状态下的缺损修复,也不会与微炎症表现出协同作用而导致牙周组织的损害。     

The effects of a bioabsorbable barrier membrane containing safflower seed extracts on periodontal healing of 1-wall intrabony defects in beagle dogs

BACKGROUND: Recently, there has been much research done into the regenerative potential of materials used in oriental medicine. In several studies, evidence was found that these materials have an effect on bone regeneration. Among these materials, safflower seeds are of particular interest as they have been used for the treatment of blood stasis, bone fracture, and osteoporosis in traditional Korean medicine. In addition, they are known to have anti-inflammatory effects. The objective of this study is to evaluate the periodontal tissue regenerative effects of a bioabsorbable barrier membrane (polylactide glycolic acid electro-spun non-woven membrane) containing safflower seed extracts applied to surgically created 1-wall intrabony defects in beagle dogs. METHODS: One-wall intrabony defects were surgically created bilaterally at the mesial and distal sides of the mandibular second premolars and mesial side of the fourth premolars. These defects were randomly assigned either to the surgical control group which received a flap operation only or to one of two experimental groups consisting of defects which received a guided tissue regenerative procedure with either a bioabsorbable membrane (PLGA) or a bioabsorbable membrane containing safflower seed extracts (SSE/PLGA). The dogs were sacrificed 8 weeks after the operation, and a comparative histological examination was done. RESULTS: The new cementum formation was 2.49+/-0.41 mm in the surgical control group, 3.22+/-0.35 mm in the PLGA group, and 3.67+/-0.82 mm in the SSE/PLGA group. The extent of new cementum formation in barrier groups was significantly different from the surgical control group (P <0.05). The amount of intrabony cementum was 1.75+/-0.06 mm, 2.40+/-0.33 mm, and 2.70+/-0.81 mm for the surgical control group, the PLGA group, and the SSE/PLGA group, respectively; the amount of infrabony cementum in the barrier groups was significantly different from the surgical control group (P<0.05). The value of the suprabony cementum was 0.73+/-0.48 mm, 0.82+/-0.21 mm, and 0.97+/-0.09 mm for the surgical control group, the PLGA group, and the SSE/PLGA group, respectively, with no significant differences being observed among the treatments. The amount of new alveolar bone formation was 1.74+/-0.25 mm, 2.36+/-0.30 mm, and 2.64+/-0.74 mm for the surgical control group, the PLGA group, and the SSE/PLGA group, respectively, with a significant difference exhibited between the surgical control group and other groups (P <0.05). Superficial root resorption was often observed, but ankylosis was not present. CONCLUSION: Our results suggest that surgical application of polylactide glycolic acid non-woven membrane with or without safflower seed extract could promote the regeneration of alveolar bone and cementum in intrabony periodontal defects.     

Healing of periodontal lesions in monkeys following the guided tissue regeneration procedure A histological study

Abstract The purpose of the present investigation was to study histologically the healing of periodontal lesions in monkeys during the first 9 weeks following periodontal reconstructive surgery according to the principle of guided tissue regeneration. Horizontal interproximal lesions and through-and-through bifurcation defects were surgically produced in 2 adult monkeys. Following removal of granulation tissue and root planing, notches indicating the level of the reduced bone level were prepared in the root surfaces. Sterile teflon membranes were then adjusted to cover the defects, and the gingival flaps were sutured in a coronally displaced position. Sacrifice of the animals was scheduled to allow for observation periods of 1, 3, 4 and 9 weeks. Evaluation of histological specimens revealed a continuous growth of new connective tissue during a period of 4 weeks. The coronal growth of new tissue did not increase significantly between 4 and 9 weeks. New cementum had formed in the most apical part of one notch after 1 week of healing, and following 3 and 4 weeks, new cementum with inserting periodontal ligament fibers were observed in all notches and to a varying degree, also more coronally on the root surfaces of both interproximal and bifurcation defects. Limited regrowth of alveolar bone was observed in the 9-week specimens. Judged from the course of the blood vessels within the newly formed connective tissue in the defects, the tissue in the central part of the defects had originated from the alveolar bone, whereas the tissue adjacent to the root surfaces seemed to have its origin in the residual periodontal ligament.     

生长因子与牙周组织再生

促进功能性牙周组织再生,重建牙槽骨、牙骨质和牙周膜的生理结构是牙周病治疗的最终目的。生长因子在牙周组织再生过程中起着重要作用,本文就牙周组织再生中生长因子的作用及其临床应用、控释技术等作一综述。     

Local osteoprotegerin gene transfer to periodontal tissue inhibits lipopolysaccharide-induced alveolar bone resorption

Background and Objective:  Osteoclastogenesis is primarily activated by receptor activator of nuclear factor κB ligand (RANKL) and is inhibited by osteoprotegerin (OPG). A previous study demonstrated that local OPG gene transfer to periodontal tissue inhibited RANKL-mediated osteoclastogenesis and experimental tooth movement. In the present study, we tested the hypothesis that local OPG gene transfer to the periodontium can neutralize RANKL activity induced by lipopolysaccharide injection, thereby inhibiting osteoclastogenesis and diminishing alveolar bone resorption in experimental periodontal disease.
Material and methods:  Seven-week-old male Wistar rats received an injection of lipopolysaccharide or phosphate-buffered saline in the palatal gingiva of the upper first molars on both the right and left sides. An inactivated haemagglutinating virus of Japan (HVJ) envelope vector containing a mouse OPG expression plasmid [pcDNA3.1(+)-mOPG] or mock vector was injected periodically into the palatal periodontal tissue of the upper first molars.
Results:  Lipopolysaccharide injection induced severe periodontal bone resorption. Local OPG gene transfer induced OPG production, and osteoclastogenesis was inhibited. Local OPG gene transfer significantly decreased alveolar bone resorption.
Conclusion:  Osteoprotegerin gene transfer to periodontal tissue inhibited osteoclastogenesis and alveolar bone resorption in lipopolysaccharide-induced experimental periodontal disease.