Objective: To investigate the therapeutic effect of methotrexate loaded vesicles on experimental periodontitis in mice. Methods: Extracellular vesicles (EVs) were isolated from human umbilical cord mesenchymal stem cells (hUC-MSC). Methotrexate loaded vesicles (MTX-EVs) were constructed, whose morphology and size were analyzed by using scanning electron microscopy and particle size analyzer. Western blotting was used to identify their surface specific proteins. C57BL/6J male mice of 4-5 weeks (provided by Experimental Animal Center of The Fourth Military Medical University) were selected, among which 8 were randomly selected by blind grasp method without treatment and fed normally as normal group, and others were induced to periodontitis models by local injection of lipopolysaccharide (LPS) into the periodontium. The LPS was injected once every day with a concentration of 2 g/L and a volume of 5 μl, lasting for two weeks. The mice with successfully induced periodontitis were randomly divided into 4 groups by blind grasping method, with 8 mice in each group. The LPS group was with no treatment, and the other three groups were treated with periodontal local injection of MTX, EVs or MTX-EVs, respectively. Two weeks later, enzyme-linked immunosorbent assay (ELISA) was used to detect the expressions of inflammatory cytokine interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in gingival tissue. The amount of alveolar bone resorption of four groups was detected by using micro-CT scanning and HE staining. The expression proportion of the inflammatory factor in gingival tissue was analyzed by using flow cytometry. Results: The scanning electron microscopy results showed that EVs and MTX-EVs were circular or elliptical in shape. Dynamic light scattering (DLS) particle size analysis showed that the particle size of EVs was around 200 nm, while that of MTX-EVs was around 300 nm. The ELISA results showed IL-1β levels in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (28.86±2.76), (51.50±2.04), (35.26±2.40), (45.49±2.04) and (35.77±3.49) ng/L. That is, the IL-1β concentrations in the LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were significantly lower than that in the LPS group (P<0.05); the mass concentration of IL-1β in the LPS +MTX-EVs group was significantly lower than that in the LPS+EVs group (P<0.05). The concentrations of IL-6 in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (125.44±4.12), (221.64±10.59), (178.16±16.90), (181.09±18.22) and (170.15±9.04) ng/L, among which the concentration of IL-6 in the last three groups were significantly lower than that in the LPS group (P<0.05). The mass concentration of IL-6 in the LPS+MTX-EVs group was significantly lower than those in the LPS+MTX group and LPS+EVs group (P<0.05). The concentrations of TNF-α in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were (320.27±38.68), (479.62±40.94), (342.18±25.89), (415.88±12.01) and (325.75±30.83) ng/L, among which the concentrations of last three groups were significantly lower than the LPS group (P<0.05); the mass concentration of TNF-α in the LPS+MTX-EVs group was significantly lower than those in the LPS+EVs group and LPS+MTX group (P<0.05). The micro-CT results showed that the distance of cement-enamel junction-alveolar bone crest (CEJ-ABC) of the first molar and root (M1R1) in the normal group, LPS group, LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group of mice were (0.11±0.03), (0.28±0.02), (0.23±0.03), (0.20±0.04), and (0.18±0.03) mm, respectively. Compared with the LPS group, the CEJ-ABC of the M1R1 in the LPS+MTX group, LPS+EVs group and LPS+MTX-EVs group were inhibited to varied degrees with statistically significant differences (P<0.05). Among them, LPS+MTX-EVs group had the best bone resorption inhibitioin effect compared to LPS+MTX group and LPS+EVs group, and the differences were statistically significant (P<0.05). The flow cytometry results indicated that the proportion of interferon-γ (IFN-γ) positive cells was (11.77±1.02)% in the LPS group, (6.87±0.65)% in the LPS+EVs group, and (4.15±0.92)% in the LPS+MTX-EVs group, respectively. The proportions of IFN-γ positive cells in the LPS+EVs group and LPS+MTX-EVs group were significantly lower than that in the LPS group (P<0.05), while the ratio of IFN-γ positive cells in the LPS+MTX-EVs group was found significantly lower than that in the LPS+EVs group (P<0.05). Conclusions: MTX-EVs can effectively alleviate the periodontal local inflammatory environment and reduce bone resorption of alveolar bone in periodontitis model mice.
目的： 探究甲氨蝶呤载药囊泡对小鼠实验性牙周炎的治疗作用。 方法： 分离人脐带间充质干细胞（hUC-MSC）的细胞外囊泡（EVs）。构建甲氨蝶呤（MTX）载药囊泡（MTX-EVs）并通过扫描电镜及动态光散射仪（DLS）对构建的载药囊泡进行形态大小分析，通过蛋白质印迹法对其表面特异性蛋白进行鉴定。选取4~5周C57BL/6J雄性小鼠40只，通过盲抓法随机抽取其中8只不做处理，正常饲养作为对照组（由第四军医大学实验动物中心提供），其余小鼠利用脂多糖（LPS）（2 g/L，5 μl）牙周局部注射诱导小鼠牙周炎模型，间隔1天注射1次，诱导2周。将成功诱导牙周炎模型小鼠通过盲抓法随机分为4组，每组8只。分别为LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组。牙周局部治疗2周后，酶联免疫吸附测定（ELISA）检测牙龈组织炎症因子白细胞介素（IL）-1β、IL-6及肿瘤坏死因子α（TNF-α）的质量浓度。通过显微CT（micro-CT）、HE染色评估对照组、LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组小鼠的牙槽骨吸收情况。流式细胞仪分析牙龈组织中γ干扰素（IFN-γ）阳性细胞的占比。 结果： 扫描电镜结果显示EVs和MTX-EVs呈圆形或椭圆形，DLS粒径分析证明EVs粒径在200 nm左右，MTX-EVs粒径在300 nm左右。ELISA结果显示，对照组、LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组IL-1β质量浓度分别为（28.86±2.76）、（51.50±2.04）、（35.26±2.40）、（45.49±2.04）、（35.77±3.49）ng/L；LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组IL-1β质量浓度均显著低于LPS组（均P<0.05）；LPS+MTX-EVs组IL-1β质量浓度显著低于LPS+EVs组（P<0.05）。对照组、LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组IL-6质量浓度分别为（125.44±4.12）、（221.64±10.59）、（178.16±16.90）、（181.09±18.22）、（170.15±9.04）ng/L；LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组IL-6质量浓度均显著低于LPS组（均P<0.05）；LPS+MTX-EVs组IL-6质量浓度显著低于LPS+EVs组和LPS+MTX组（均P<0.05）。对照组、LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组TNF-α质量浓度分别为（320.27±38.68）、（479.62±40.94）、（342.18±25.89）、（415.88±12.01）、（325.75±30.83）ng/L；LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组TNF-α质量浓度均显著低于LPS组（均P<0.05）；LPS+MTX-EVs组TNF-α质量浓度显著低于LPS+EVs组及LPS+MTX组（均P<0.05）。micro-CT扫描结果显示，对照组、LPS组、LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组小鼠右上颌第一磨牙第一牙根处釉质牙骨质界到牙槽嵴顶的距离分别为（0.11±0.03）、（0.28±0.02）、（0.23±0.03）、（0.20±0.04）、（0.18±0.03）mm，与LPS组相比，LPS+MTX组、LPS+EVs组及LPS+MTX-EVs组骨吸收均得到不同程度的抑制，差异均有统计学意义（均P<0.05），其中LPS+MTX-EVs组与LPS+MTX组及LPS+EVs组相比，骨吸收抑制效果最好，且差异均有统计学意义（均P<0.05）。流式细胞仪检测结果显示，LPS组、LPS+EVs组及LPS+MTX-EVs组IFN-γ阳性细胞占比分别为（11.77±1.02）%、（6.87±0.65）%及（4.15±0.92）%，LPS+EVs组及LPS+MTX-EVs组中IFN-γ阳性细胞占比均显著低于LPS组（均P<0.05），LPS+MTX-EVs组中IFN-γ阳性细胞占比显著低于LPS+EVs组（P<0.05）。 结论： MTX-EVs可有效改善牙周炎模型小鼠牙周局部炎症环境，减少小鼠牙槽骨骨吸收。.