Fe3O4纳米粒子的细胞相容性

背景：无论是作为化疗药物载体还是作为肿瘤热疗介质,Fe₃O₄纳米粒子与肿瘤细胞微观结构的作用都有待于深入研究。 目的：分析Fe₃O₄纳米粒子的细胞相容性,探讨其在骨肉瘤化疗中作为药物载体的应用和存在的问题。 方法：参照GB/T16886.5-2003 (医疗器械生物学评价 第5部分：体外细胞毒性试验)的评价标准和要求,偶联十六烷基三甲基溴化铵、聚乙二醇、油酸钠Fe₃O₄纳米粒子胶体溶液,分别与大鼠原发骨肉瘤细胞和人成纤维细胞共培养的方式对其进行细胞毒性测试。 结果及结论：偶联油酸钠Fe₃O₄纳米粒子细胞相容性良好,参照GB/T16886.5-2003标准属于安全范围。偶联十六烷基三甲基溴化铵Fe₃O₄纳米粒子细胞相容性差,不适宜作为化疗药物载体进入人体。偶联聚乙二醇Fe₃O₄纳米粒子有一定的细胞相容性,作为磁靶向热化疗载体还需研究。     

Fe3O4磁性微粒的制备及表征

背景：磁性微粒作为一种磁性载体在固定化酶、免疫检测、靶向载药治疗及细胞分离等生物医学领域得到了广泛的应用。 目的：制备分散稳定性好,相对磁性强的纳米级Fe₃O₄微粒。 方法：以氯化亚铁、氯化铁、氢氧化钠为主要原料,采用化学共沉淀法合成Fe₃O₄磁性粒子。 结果与结论：用正交设计法优化了Fe₃O₄微粒的合成工艺条件,得到制备Fe₃O₄粒子的最佳实验条件为Fe²⁺/Fe³⁺的物质的量之比为2∶1、共沉淀时的pH值为11、熟化温度为90 ℃、表面活性剂聚乙二醇的用量为40 mL,此时制得的Fe₃O₄粒子粒径最小,为78 nm,Fe₃O₄溶液的分散稳定性最好,相对磁性最强。从Fe₃O₄的扫描电镜图可以看出,Fe₃O₄微粒晶体颗粒为纳米级。     

载TK基因PEG-PEI Fe3O4纳米磁流体体外肿瘤细胞抑制的研究

目的:研究载TK基因PEG-PEI Fe3O4纳米磁流体体外肿瘤细胞抑制特性.方法:以RT-PCR方法鉴定其在各细胞系中mRNA水平上的表达状况.采用MTT法研究载TK基因纳米颗粒体外抑制肿瘤细胞的生长作用.结果:PEG-PEI Fe3O4纳米磁流体能有效的转染pAFP-TK进入AFP阳性的HepG2细胞,并在细胞内得以正常表达.MTT法显示,AFP阳性的细胞在转染pAFP-TK后对GCV的敏感性大大提高,细胞存活率明显下降.结论:PEG-PEI Fe3O4纳米磁流体能高效转染pAFP-TK质粒进入细胞,并在AFP阳性肝癌细胞中获得特异性表达,加用GCV后,还可高效杀伤AFP阳性肝癌细胞.     

二巯基丁二酸修饰的Fe3O4纳米颗粒对人血管内皮细胞的作用研究

目的研究二巯基丁二酸修饰的Fe3O4纳米颗粒(dimercaptosuccinic acid-magnetite nanoparticles,DMSA-Fe3O4)对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)功能的影响。方法利用动态光散射法表征DMSA-Fe3O4的粒径及表面电荷;采用普鲁士蓝染色、邻二氮菲铁定量和透射电镜观察方法研究HUVECs对DMSA-Fe3O4的摄取规律;利用细胞计数试剂盒(Cell Counting Kit-8,CCK-8)检测DMSA-Fe3O4对内皮细胞活性的影响;通过酶联免疫吸附试剂盒测定DMSA-Fe3O4对内皮细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)分泌量的影响。结果HUVECs能够大量吞噬DMSA-Fe3O4,其吞噬量具有孵育时间和剂量依赖性;短时间内所测剂量范围DMSA-Fe3O4对细胞活性无显著影响,但长时间高剂量条件使细胞活性明显降低。此外,在高剂量DMSA-Fe3O4暴露下(200μg/mL),内皮细胞分泌VEGF的量约为对照组的3倍。结论DMSA-Fe3O4易于被HUVECs吞噬;高浓度DMSA-Fe3O4与HUVECs长时间培养使细胞活性降低,并刺激内皮细胞分泌VEGF。     

超顺磁性Fe2O3与Fe3O4用于磁共振胃肠造影剂的粒度比较

目的探讨应用超顺磁性Fe2O3与Fe3O4制备磁共振造影剂的可能性。方法根据超顺磁性理论推导出两种微粒显示超顺磁现象的临界尺寸理论值。根据磁学理论,分析了磁共振造影剂稳定的机理,推导出在磁共振磁场中,两者在造影剂中稳定悬浮的极限尺寸。结果超顺磁性Fe2O3与Fe3O4显示超顺磁现象的临界尺寸理论值分别为24．8nm和31．6nm,在1．5T磁共振磁场中的临界值为7．1nm和11．1nm;在造影剂中稳定悬浮的极限尺寸为13．3nm和14nm。结论超顺磁性Fe2O3与Fe3O4在造影剂中,既能稳定悬浮又具有超顺磁性的临界尺寸为7．1nm、11．1nm。     

不规则形貌纳米 Fe3O4 介导的磁场机械力杀伤肿瘤细胞

目的 考察Fe₃O₄纳米颗粒在低频振动磁场(low-frequency vibrating magnetic field, VMF)驱动下通过磁场机械力杀伤肿瘤细胞的效果。方法 通过共沉淀法合成一种磁性强、具有不规则形貌的立方相Fe₃O₄纳米颗粒。将其置于本课题组自制的VMF中,研究其介导的磁场机械力对肿瘤细胞的杀伤效果。结果 单纯施加VMF对细胞活力无影响;加入Fe₃O₄纳米颗粒后,细胞活力随VMF处理时间和Fe₃O₄纳米颗粒浓度的增加而降低,受损细胞释放的乳酸脱氢酶也随磁场处理时间延长而增加。结论 不规则形貌Fe₃O₄纳米颗粒在VMF下可将机械力转移到肿瘤细胞,破坏细胞结构,导致细胞死亡;所采用的VMF装置结构简单、使用安全、操作方便。所采用的磁性粒子及其杀伤肿瘤细胞的方法,有临床转化潜力。     

生物相容性Fe3O4@SiO2纳米粒子的合成及性能

背景：Fe₃O₄纳米粒子具有良好的磁学特性,SiO₂具有良好的生物相容性,Fe₃O₄@SiO₂复合纳米粒子有望成为靶向治疗的载体。 目的：采用反相微乳液法合成生物相容性的Fe₃O₄@SiO₂纳米粒子。 方法：首先,以FeCl₃•6H₂O、FeCl₂•4H₂O、油酸、氨水等为原料,采用一壶化学共沉淀法合成油酸修饰的疏水性Fe₃O₄纳米粒子。随后,将油酸包裹的Fe₃O₄纳米粒子分散于环己烷中,然后将Triton-X100、正己醇及水在搅拌条件下加入到上述溶液,形成稳定的反相微乳液;在反相微乳液中,以氨水为催化剂,使正硅酸四乙酯水解、缩合,从而获得Fe₃O₄@SiO₂复合纳米粒子。 结果与结论：①透射电镜、X射线衍射显示：采用一壶化学沉淀法合成的Fe₃O₄具有尖晶石结构,平均粒径约为3.5 nm;微乳液法能将SiO₂成功包覆于Fe₃O₄表面,形成平均粒径为40 nm的均一Fe₃O₄@SiO₂复合纳米粒子。②磁性能分析显示：Fe₃O₄纳米粒子包裹后饱和磁化强度下降,但包裹前后矫顽力趋于零,均显示超顺磁性。③MTT结果显示纳米粒子与人脐静脉细胞融合细胞(EA.hy926)共培养24 h时Fe₃O₄@SiO₂组吸光度高于对照组(P < 0.05);细胞培养48,72 h,两组比较差异无显著性意义(P > 0.05)。结果表明经反相微乳液法合成的Fe₃O₄@SiO₂纳米粒子是一种优良的生物材料,其具有稳定、易分散及超顺磁性等特性。     

载顺铂超顺磁γ-Fe2O3纳米粒子的制备与表征*☆

背景：将化疗药物联接在磁性纳米载体上,在外加磁场的引导下使所载药物定向集中于靶向治疗部位,在增强疗效同时还可降低毒性不良反应。 目的：制备海藻酸钠改性的磁性纳米粒子及其负载顺铂药物,分析产物的磁学性质。 方法：通过Fe2+在乙醇胺水溶液中一步合成磁性纳米粒子,用海藻酸钠作偶联剂使磁性纳米粒子与顺铂相连,制备磁性纳米粒子药物。 结果与结论：X射线衍射花样证明产物为γ-Fe2O3纯相,透射电子显微镜表明磁性纳米粒子直径平均约10 nm,载顺铂后药物包覆于纳米粒子周围,磁化曲线显示纳米粒子为超顺磁性,核磁共振得到纳米粒子的弛豫率为0.116 02 mmol/ms。表明所制备磁性纳米粒子及其载顺铂超顺磁性纳米粒子药物性质稳定,具有作为磁性纳米粒子药物的特性。 关键词：磁性纳米粒子药物;顺铂;超顺磁性;Fe2O3;生物材料与药物控释 doi:10.3969/j.issn.1673-8225.2012.12.011     

新型脊髓纳米组织工程支架的组织相容性

背景：纳米技术可改善脊髓组织工程生物材料的性能。 目的：分析新型脊髓纳米组织工程支架的组织相容性。 方法：以胶原为原料制备纤维定向排列及非定向排列的纳米纤维膜,培养及鉴定SD大鼠脊髓源性神经干细胞。将两种纳米纤维膜与SD乳鼠脊髓源性神经干细胞共培养,以正常培养的神经干细胞为对照,通过MTT实验检测纳米纤维膜的细胞相容性;以扫描电镜检测细胞在纳米纤维膜表面的黏附及增殖情况;将纳米纤维膜植入SD大鼠体内,通过组织学检查确定其降解情况及组织相容性;通过免疫组织化学实验确定神经干细胞在体内的存活及移动情况。 结果与结论：两种纳米纤维膜表面的神经干细胞黏附及增殖情况良好,MTT实验结果表明纳米纤维膜的细胞相容性佳,电镜结果表明细胞在纳米纤维膜表面黏附良好,增殖情况佳;在体内纳米纤维膜降解情况良好,组织相容性佳;BrdU标定的神经干细胞在SD大鼠体内存活并移动情况良好。结果表明新型纳米组织工程支架具有良好的细胞及组织相容性。     

偏磷酸钙纳米粒子的细胞相容性

背景：偏磷酸钙具有优异的细胞相容性能和降解性能及细胞亲和性,人骨髓间充质干细胞可以在多孔偏磷酸钙孔洞内生长和增殖,但有关偏磷酸钙纳米粒子的研究较少。 目的：制备纳米级偏磷酸钙微粒,通过流式细胞术快速检测不同浓度纳米级偏磷酸钙微粒对人骨髓间充质干细胞凋亡的影响。 方法：采用湿法球磨法制备偏磷酸钙纳米粒子,通过扫描电镜和透射电镜观察纳米粒子的形貌,通过X射线衍射分析确定纳米粒子的晶体结构。将偏磷酸钙纳米粒子混入CYAGON OricellTM 基础培养基,使得偏磷酸钙纳米粒子的质量浓度分别为10,1,0.1 mg/L,将其与人骨髓间充质干细胞共培养7 d,通过流式细胞术分析偏磷酸钙纳米粒子质量浓度与细胞凋亡的关系。 结果与结论：采用湿法球磨法成功制备了偏磷酸钙纳米粒子,直径为10-30 nm,粒径分布较均匀,分散性较好,但晶体形状不规则;X射线衍射分析晶相检测其主晶相为β-Ca(PO3)2晶体。10 mg/L质量浓度组细胞G0/G1和G2/M比例高于1,0.1 mg/L质量浓度组(P < 0.01);10 mg/L质量浓度组细胞早期、中晚期、总细胞凋亡率高于1,0.1 mg/L质量浓度组(P < 0.01);说明偏磷酸钙纳米粒子对人骨髓间充质干细胞的增殖有影响,当其质量浓度从1 mg/L增加至10 mg/L后,细胞凋亡率显著增加。     

磁性四氧化三铁纳米颗粒作用于前成骨细胞的生物相容性

BACKGROUND: Investigations on toxic mechanism and safety of magnetic ferrosoferric oxide (Fe3O4) nanoparticles are extremely necessary when these nanoparticles as an emerging material for bone tissue engineering are implanted into the living body. OBJECTIVE: To investigate the biocompatibility of magnetic Fe3O4 nanoparticles with preosteoblasts. METHODS: Mouse preosteoblasts were cultured in 0, 200, 400, 800 mg/L magnetic Fe3O4 nanoparticles. After 24 hours, alkaline phosphatase activity, osteocalcin level, cell proliferation rate, cellular morphology, cytoskeleton variation, cell apoptosis and autophagy-related genes, such as Caspase-3, LC3A, LC3B, were detected by alkaline phosphatase assay kit, ELISA kit, cell counting kit-8 kit, inverted microscope, laser confocal microscopy and real-time PCR, respectively. RESULTS AND CONCLUSION: After 24 hours of culture, there ware no significant differences between 200 mg/L group and control group. However, in the groups of 400 and 800 mg/L, the ratio of alkaline phosphatase activity to total protein and osteocalcin level increased, the cell proliferation rate decreased, cellular morphology and cytoskeleton changed remarkably, LC3B expression was up-regulated compared with the control group. Additionally, there were also no significant differences in the expression of Caspase-3 and LC3A between 400 and 800 mg/L groups and control group. Therefore, magnetic Fe3O4 nanoparticles at high level contributes to cytotoxicity and up-regulation of LC3B expression, and affects cellular morphology, cytoskeleton and cell proliferation rate, although these nanoparticles can increase the osteoblastic differentiation.        

银纳米颗粒及载银抗菌涂层的研究与进展

BACKGROUND: Current numerous studies have confirmed that silver nanoparticles have been extensively applied due to their good anti-bacterial performances.     

一氧化氮及一氧化氮合酶抑制剂对髓核细胞线粒体功能的影响

BACKGROUND: Nitric oxide can interfere with the function of mitochondria, and accelerate the intervertebral disc damage and degeneration by interfering with the release of inflammatory cytokines. Nitric oxide is an important inflammatory cell medium leading to degeneration of intervertebral disc induced by pressure and other external factors. OBJECTIVE: To investigate the regulatory effect of nitric oxide and nitric oxide synthase inhibitor niacinamide on mitochondrial function and its association with biological behavior of rabbit nucleus pulposus. METHODS: Cultured nucleus pulposus cells of rabbit lumbar intervertebral disc were randomly divided into six groups: normal blank control group, 10 μmol/L sodium nitroprusside group, 100 μmol/L sodium nitroprusside group, 200 μmol/L sodium nitroprusside group, 0.05 g/L nicotinamide group (100 μmol/L sodium nitroprusside+0.05g/L nicotinamide), and 0.5 g/L nicotinamide group (100 μmol/L sodium nitroprusside and 0.5 g/L nicotinamide). Different doses of nitric oxide donor sodium nitroprusside and nicotinamide were added in the medium of each group. Three days after intervention, cell proliferation activity, intracellular ATP concentration, cell nitric oxide synthase activity, cellular reactive oxygen species level, and mitochondrial membrane potential were detected respectively. RESULTS AND CONCLUSION: (1) After 3 days of rabbit nucleus pulposus cells intervened by different concentrations of sodium nitroprusside, intracellular nitric oxide synthase content increased with sodium nitroprusside volume increase, and ATP concentration decreased along with sodium nitroprusside volume increase; there were significantly differences between the normal control group and sodium nitroprusside groups (P < 0.01). (2) Reactive oxygen species could be increased in the sodium nitroprusside group. Niacinamide groups indicated a dose-dependent manner to improve the increase of cellular reactive oxygen species levels with sodium nitroprusside intervention (P < 0.01). (3) In the sodium nitroprusside groups, nucleus pulposus cell membrane potential decreased. In the niacinamide groups, sodium nitroprusside- induced decline in mitochondrial membrane potential was reduced (P < 0.01). (4) Niacinamide groups also indicated a dose-dependent manner to improve the proliferative activity of nucleus pulposus cells as compared with sodium nitroprusside groups (P < 0.01). Significant differences were determined between the two groups (P < 0.01). (5) Results suggest that the excess nitric oxide can damage mitochondrial metabolic function of rabbit nucleus pulposus cells and cause cell energy metabolism. Niacinamide can reverse these damages by inhibiting nitric oxide synthesis, thereby contributing to the prevention against intervertebral disc degeneration. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

吸入上转换纳米颗粒对小鼠肺肝均有一过性损害

BACKGROUND: Lots of in vitro experiments have explored the toxicity of upconversion nanoparticles, but its toxicity in vivo is little reported. OBJECTIVE: To investigate the toxicity of upconversion nanoparticles in mouse organs. METHODS: After tracheotomy, 36 Balb/c mice were randomly divided into three groups, followed by instilled with 28 mg/kg upconversion nanoparticle (experimental group), the same volume of normal saline (control group), and nothing (sham operation group), respectively. The functional changes of the lung, liver and kidney were detected at 1 day, 1 and 2 weeks postoperatively, and meanwhile, the morphological changes of the lung, liver, kidney, and heart were observed. RESULTS AND CONCLUSION: At 1 day postoperatively, the pH values in the experimental group were lower than those in the control and sham operation groups (P < 0.05), while the glutamic-pyruvic transaminase level was higher than that in the control and sham operation groups (P < 0.05). The oxygen partial pressure in the sham operation group was higher than that in the other two groups at 1 day postoperatively (P < 0.05). The oxygen partial pressure and glutamic-pyruvic transaminase level did not significantly differ among groups at 1 and 2 weeks postoperatively. The carbon dioxide differential pressure and kidney function showed no significant differences among groups at different time points after surgery. At postoperative 1 day, in the experimental group, hyperplasia and inflammation were most obvious, distorted alveolar cavity and congestion of blood vessels were visible. In the control group, obvious hyperplasia and inflammation were found, the alveolar cavity was crimped and the gap between alveoli was broadened. The sham operation group had normal alveoli with no inflammations. Lung lesions in the experimental and control groups became mild with time at postoperative 1 and 2 weeks. One day postoperatively, hepatocyte swelling and vacuolar degeneration were severer in the experimental group. Moderate hepatocyte swelling and vacuolar degeneration occurred in the control group. The sham operation group showed mild hepatocyte swelling and vacuolar degeneration. The morphology of the liver in each group returned to normal at 2 weeks postoperatively. Fortunately, the heart and kidney structure showed no overt changes in each group. These findings suggest that upconversion nanoparticles cause transient damage to the mouse lung and liver.     

聚乙二醇修饰载血管紧张素转化酶RNA壳聚糖纳米粒治疗高血压

BACKGROUND: Traditional antihypertensive drugs always have a short half-life period, and show unsatisfactory treatment outcomes. Chitosan, as a gene vector, can carry target genes into the designated location. Polyethylene glycol (PEG) combined with DNA to form the nanoparticles, which can provide surface protection, stabilize the nanoparticles and lengthen the nanoparticle’s half-life. OBJECTIVE: To investigate the antihypertensive effect and the histological changes of heart after PEG-modified chitosan nanoparticles loaded with angiotensin converting enzyme (ACE)-shRNA injected into the rat models of spontaneous hypertension. METHODS: There were five groups: 32 rats with hypertension were randomized into model, chitosan experimental and positive drug groups (n=8 per group); another 8 healthy rats served as controls. The rats in the model and control groups were given the injection of the same amount of normal saline via tail vein, the rats in the chitosan group received the injection of 1 mg/kg chitosan via the tail vein, those in the experiment group received the injection of 1 mg/kg PEG-modified chitosan nanoparticles loaded with ACE-shRNA, and the positive drug group rats were treated with 0.5 mg/kg benazepril hydrochloride via gastric lavage at 1 and 10 days, respectively. RESULTS AND CONCLUSION: The blood pressure in the experimental group at 3 days after treatment was significantly lower than that at 1 day (P < 0.05). Aorta, renal and cardiac biopsies showed positive for green fluoresce in the experimental group, which was consistent with the in vivo distribution of ACE. At 3 days after treatment, compared with the model group, in the experimental group, ACE mRNA expression and levels of myocardial hypertrophy-related indicators were significantly decreased, and myocardial hypertrophy was significantly improved (P < 0.05). These results revealed that PEG-modified ACE-shRNA chitosan nanoparticles can reduce the blood pressure and repair the injured heart of rat models of hypertension, which may be associated with ACE.     

壳聚糖纳米粒包裹反义内皮素转换酶核酸表达质粒与哮喘气道高反应性

背景：有研究报道体外实验环境下,反义内皮素核酸纳米载体经12-烷基化壳聚糖纳米粒包裹之后可以表达目标核酸,产生RNA干扰效应,达到有效抑制变应原诱导炎症因子内皮素过度生成的效果。目的：观察12-烷基化壳聚糖纳米粒包裹反义内皮素转换酶核酸表达质粒对哮喘模型小鼠气道高反应性的影响。方法：将40只Balb/c小鼠随机均分为4组,壳聚糖纳米组、生理盐水组及质粒组腹腔注射卵清蛋白致敏(0,14 d)、雾化吸入卵清蛋白激发(24,25,26 d),诱导哮喘模型;对照组给予生理盐水致敏、激发。首次激发前24 h,对照组、壳聚糖纳米组、生理盐水组、质粒组分别经气道灌注生理盐水、包裹反义内皮素转换酶核酸的12-烷基化壳聚糖纳米粒、生理盐水及反义内皮素转换酶核酸。末次激发后48 h,检测小鼠气道反应性;28 d后,进行支气管肺泡灌洗液细胞学、肺组织病理学、脾细胞培养上清液细胞因子检测。结果与结论：与对照组比较,壳聚糖纳米组、生理盐水组、质粒组细胞总数、嗜酸性粒细胞百分比、嗜酸性粒细胞绝对计数、白细胞介素4水平、内皮素水平及气道反应性均升高(P < 0.05),肺部炎症程度较重;壳聚糖纳米组上述指标均低于生理盐水组、质粒组(P < 0.05),炎症程度轻于生理盐水组、质粒组。表明12-烷基化壳聚糖纳米粒包裹反义内皮素转换酶核酸表达质粒可降低哮喘内皮素合成量,抑制气道高反应性。  中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

5-氟尿嘧啶聚乳酸载药纳米微粒对胃癌细胞株的体外杀伤作用

背景：5-氟尿嘧啶在胃癌治疗中占据重要地位,但是长期服用容易出现骨髓抑制、白细胞减少等不良反应。聚乳酸及共聚物载药微粒材料生物相容性较高,分解物不会在机体内发生聚集。目的：探讨聚乳酸载药纳米微粒对胃癌细胞株的体外杀伤作用机制。方法：选取10只小鼠进行实验,利用超声乳化方法制备5-氟尿嘧啶聚乳酸载药纳米微粒,并采用噻唑蓝比色法配制1×10^-7,1×10^-6,1×10^-5,1×10^-4 mol/L的5-氟尿嘧啶聚乳酸载药纳米微粒,检测其对小鼠胃癌细胞的体外杀伤效应,并且计算出药物的抑制率浓度以及对胃癌细胞的生长抑制能力等以及凋亡的诱导作用。结果与结论：透射电镜下观察5-氟尿嘧啶聚乳酸载药纳米微粒：形态完好,分布相对均匀,不出现粘连等现象,用药24 h药物浓度可达到50%,72 h后能够达到62.9%;不同浓度下单一5-氟尿嘧啶和5-氟尿嘧啶聚乳酸载药纳米微粒和小鼠胃癌细胞联合培养48 h后,细胞的活性随着药物浓度的提高出现下降趋势,并且5-氟尿嘧啶聚乳酸载药纳米微粒细胞抑制能力显著高于5-氟尿嘧啶(P < 0.05);5-氟尿嘧啶聚乳酸载药纳米微粒的IC₅₀显著低于5-氟尿嘧啶(P < 0.05)。结果证实聚乳酸纳米微粒具有优良的药物载体作用,载药量较大,在机体内提高药物浓度,并且不降低5-氟尿嘧啶成分的生物学活性,可为胃癌治疗提供新思路。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

构建叶酸修饰的乳腺癌靶向纳米超声造影微粒

BACKGROUND: Studies have testified that nano-ultrasound contrast agents have a strong permeability, making it possible to image the targeted tissues outside blood vessels and overcome the limitation that micron contrast agents are only available for the blood pool imaging. OBJECTIVE: To construct the folate-modified nanoparticles targeting breast cancer as ultrasound contrast agents, as well as to observe their ability to specifically bind to cells and imaging effect in vitro. METHODS: Both contrast agents, pegylated lactic acid-glycolic acid copolymer wrapping liquid fluorocarbon formed nanoparticles (mPP/PFOB) and folate modified pegylated lactic acid-glycolic acid wrapping liquid fluorocarbon formed nanoparticles (mPPF/PFOB), were constructed by phacoemulsification-evaporation method. (1)Biocompatibility detection: HFF-1 and MCF-7 cells in the logarithmic phase were cultivated with various concentrations (0, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2 and 1 g/L) of mPP/PFOB or mPPF/PFOB for 24 hours respectively, and then the cell viability was measured. (2)Targeting ability detection in vitro: HFF-1 and MCF-7 cells in the logarithmic phase were divided into three groups. Cy5-labled mPP/PFOB and mPPF/PFOB were added into groups A and B, respectively; the cells in group C were pretreated with folate for 2 hours, and sequentially Cy5-labled mPPF/PFOB was added into group C. Fluorescence intensity was detected by flow cytometry after 0.5 hours of culture. The distribution of contrast agents in cells was observed using confocal microscopy after 20 minutes of culture. (3)Ultrasound imaging in vitro: there were three groups: saline was as group A; the suspension of saline and mPPF/PFOB nanoparticles was prepared as group B; MCF-7 cells were resuspended with the mixture of saline and mPPF/PFOB nanoparticles to prepare the suspension of nanoparticles and cells as group C. In each group, the suspension was added into latex gloves, that were then tightened and immersed in water. Finally, the ultrasound was use to detect the ultrasound imaging effect in vitro. RESULTS AND CONCLUSION: Neither nanoparticles were with significant cytotoxicity. The flow cytometry showed that the mean fluorescence intensity in MCF-7 cells of group B was significantly higher than that of groups A and C. But there were no significant differences in the mean fluorescence intensity in HFF-1 cells among the three groups. It was observed that mPPF/PFOB mainly gathered around the MCF-7 cell membrane, while mPP/PFOB randomly distributed in the cytoplasm. After mPPF/PFOB binding to MCF-7 cells, they could enhance ultrasound echo in vitro. These findings indicate that the targeted nanoparticles mPPF/PFOB have good biocompatibility and can specifically bind to breast cancer MCF-7 cells in vitro and enhance the imaging capability.     

球形多孔微载体支持下高密度培养人肝细胞L-02的定时形态变化

背景：微载体培养技术作为一项体外高浓度细胞培养技术,近年来已在肝细胞的体外培养中得到应用。 目的：对壳聚糖球形多孔微载体培养的人肝细胞L-02进行定时的形态学观察。 方法：以自制的壳聚糖球形多孔微载体样本为支架来培养人肝细胞L-02设为实验组;无壳聚糖球形多孔微载体支持下人肝细胞的培养设为对照组。对两组细胞进行定时的细胞计数,对实验组进行形态学观察,包括倒置相差生物显微镜观察和扫描电子显微镜观察。 结果与结论：两组培养的细胞数量均呈现前3 d增长,在培养第3天细胞数量达到最高值;实验组3个样本培养的细胞数明显高于对照组无微载体培养的细胞数量(P < 0.05),实验组各样本之间细胞数差异无显著性意义(P > 0.05)。倒置相差生物显微镜下动态观察,可见前3 d微载体表面黏附生长的肝细胞则逐渐增多,培养第3天可见大部分微载体表面有许多肝细胞黏附成团,总的存活率均在90%以上,且肝细胞保持着良好的形态学结构;扫描电子显微镜观察,微载体表面、切面和内部均可看到有许多球状肝细胞紧密黏附。结果说明,以自制的壳聚糖球形多孔微载体作为一种支架,在体外三维环境下可以进行高浓度细胞培养。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

新型复合壳聚糖季铵盐纳米粒子抗感染骨水泥的生物学特性

BACKGROUND: Postoperative infection in patients underlying total knee arthroplasty is a long-standing puzzle. Current bone cement with antibiotics cannot effectively treat kidney function deficiency and bacterial resistance. OBJECTIVE: To develop a novel kind of bone cement prepared by quaternary ammonium salt chitosan nanoparticles. METHODS: There were three groups including QCSNP-15, Palacos R and Palacos R+G groups. Morphology of the bone cement in each group was observed using scanning electron microscope, the setting time of bone cement was measured, and the in vitro compression strength, cytotoxicity and antibacterial activity tests were performed. RESULTS AND CONCLUSION: Scanning electron microscope observed that QCSNP-15 was made of quaternary ammonium salt chitosan nanoparticles and methyl methacrylate copolymer, and these nanoparticles distributed onto the material surface. The setting time of QCSNP-15 was longer than that of the Palacos R+G bone cement. The compressive strength of QCSNP-15 was significantly lower than that of the Palacos R bone cement (P < 0.05), but was larger than 70 MPa stipulated by ISO 5833. Osteoblasts MC3T3-E1adhered well on the QCSNP-15, and pseudopodia fully expanded. Similar findings were observed on the Palacos R+G bone cement. The attachment rate of osteoblasts of the QCSNP-15 at 3 hours was significantly lower than that of the Palacos R+G bone cement (P < 0.05). The antibacterial activity did not significantly differ between QCSNP-15 and Palacos R+G bone cements, even after 2-week immersion in the PBS. These findings suggest that QCSNP-15 exhibits appropriate setting time, good biomechanical property and antibacterial activity in vitro with no obvious cytotoxicity.