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1.
目的:观察半乳糖基壳聚糖(GC)/5-氟尿嘧啶(5-FU)纳米粒抑制小鼠原位肝癌移植模型的疗效及机制.方法:合成GC/5-FU纳米粒,建立小鼠原位肝癌移植模型,通过动物实验观察GC/5-FU纳米粒治疗小鼠原位肝癌移植模型的疗效,通过原位末端标记法(TUNEL法)检测肝癌的凋亡.结果:GC/5-FU纳米粒成功合成,呈规则的球形,表面光滑,大小均匀,纳米粒间无粘连.实验结束时,小鼠的肝癌组织称重,进行方差分析发现GC/5-Fu的瘤重为(0.4361±0.1153)g,5-Fu组为(0.7932±0.1283)g,GC为(1.3989±0.2125)g,和对照组为(1.5801±0.2821)g,4组瘤重之间差异有显著的统计学意义(P<0.01).GC/5-FU组和5-FU组的瘤重明显小于GC组及对照组,差异有统学意义(P<0.01);GC/5-FU的瘤重又显著小于5-Fu组(P<0.01).观察各组小鼠的生存期发现对照组的中位生存时间为12d,GC组为13d,5-FU为17d,而GC/5-FU组最高为30d.GC/5-FU组的生存时间最长.通过TUNEL法观察肝癌细胞的凋亡发现GC/5-FU组的平均凋亡指数(AI)为21.34%较5-FU组的14.74%明显增高(P<0.05),均较GC组和对照组明显增高,而GC组和对照组间的AI无明显差异(P>0.05).结论:GC/5-FU纳米粒在体内对小鼠原位肝癌具有明显抑制作用,较5-FU明显增强.其机理可能与GC能通过细胞膜将5-FU从细胞外转移到细胞内,增强5-FU对肝癌细胞的凋亡.  相似文献   

2.
聚乙二醇- 聚乳酸嵌段共聚物纳米粒的研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
聚乙二醇-聚乳酸嵌段共聚物(PEG-PLA)及其端基衍生物纳米粒可以增强载药量、降低突释效应、提高药物在血液中的循环时间、提高生物利用度,并且其粒径更小,能以被动靶向的方式聚集于炎症或靶向部位。本文综述了PEG-PLA嵌段共聚物纳米粒的最新进展,包括PEG-PLA的合成、纳米粒的制备、释药特性及在药物制剂中的应用。  相似文献   

3.
目的:利用糖尿病大鼠模型,研究载有胰岛素纳米粒的降血糖作用。方法:雄性SD大鼠18只,禁食12 h后,尾静脉一次性注射5%四氧嘧啶40 mg/kg制备大鼠糖尿病模型。超声条件下,制备含胰岛素纳米粒,纳米悬液的胰岛素浓度为2 U/ml,于4℃冷藏保存。大鼠随机分为三组,口服胰岛素组(A组)、载胰岛素纳米粒组(B组)、皮下注射胰岛素组(C组)。分别于灌胃前、灌胃后0.5,1,2,4,8,12 h取血测定血糖。结果:口服载胰岛素纳米粒后能显著降低大鼠的血糖水平,起效时间晚于皮下注射胰岛素,但作用时间长久;而口服等量普通胰岛素血糖无明显变化。表明HTCC-ALG/OREC纳米粒在体内对胰岛素具有保护作用。结论:载胰岛素纳米粒具有一定的降血糖作用和缓释效果,是具有很好应用前景的口服蛋白质给药载体。  相似文献   

4.
李宁  于力方  王珊  廖杰 《现代生物医学进展》2012,12(30):5836-5837,5867
目的:观察阿霉素纳米粒对多耐受糖蛋白介导的膀胱移行细胞癌多耐药的逆转.方法:MTT法观察MDR逆转,采用流式细胞仪对细胞内阿霉素浓度进行检测.结果:阿霉素纳米对敏感株的细胞毒作用与阿霉素差异无显著性意义,耐药株对阿霉素纳米较对阿霉素纳米粒敏感4.8倍,表现细胞内阿霉素显著增高.结论:阿霉素纳米可有效逆转P-gp介导的多药耐药.  相似文献   

5.
载基因壳聚糖纳米粒的制备及免疫增强作用的初步研究   总被引:2,自引:0,他引:2  
摘 要 目的: 制备壳聚糖载基因纳米粒,并对其体外转染效率及其在小鼠体内的免疫增强效果进行初步研究。方法: 以本课题组构建的口蹄疫DNA疫苗为模型药物,采用复凝聚法制备纳米粒;用透射电镜观察形态;用纳米粒度分析仪测定粒径、多分散度和zeta电位;凝胶阻滞分析测定基因在纳米粒中的位置;用体外基因转染实验评价纳米粒的转染活性。用载基因壳聚糖纳米粒免疫雌性Balb/c小鼠,检测免疫小鼠的细胞免疫和体液免疫水平。结果: 所制备的载基因纳米粒形态规则、大多成球形,平均粒径约为150nm,多分散度<0.26,zeta电位约为21mV;凝胶分析结果表明质粒DNA与壳聚糖分子间可以通过电性结合作用而完全结合,基因几乎全部被包裹在纳米粒内部;体外基因转染实验表明壳聚糖作为一种新型的非病毒基因递送载体能够高效传递DNA进入BHK-21细胞,基因能够在该细胞中高效表达;小鼠免疫实验表明纳米粒不仅能诱导机体产生较高的细胞免疫水平,而且体液免疫水平也显著提高。结论: 壳聚糖纳米粒能将基因递送到细胞内并且能够表达,小鼠免疫实验显示其具有良好的免疫增强效果。  相似文献   

6.
以新型材料聚乳酸(PLA)为载体,研制出质量稳定的藤黄酸聚乳酸纳米粒(GA-PLA-NPs)乳液制剂,并对其安全性进行评价。采用改良的溶剂蒸发法制备藤黄酸聚乳酸纳米粒(GA-PLA-NPs);用透射电子显微镜(TEM)观察纳米粒的形态;用激光粒度分析仪测定其平均粒径大小和分布;经超速离心后用紫外分光光度计测定纳米粒的包封率与载药量;考察藤黄酸纳米粒的体外释放特性;经急性毒性实验考察藤黄酸纳米粒的安全性。得到确定处方工艺为:水相∶有机相为2∶1(v/v),表面活性剂在有机相中的浓度为0.5%(w/v),藤黄酸(GA)在有机相中的浓度为0.1%(w/v),GA∶PLA为1∶4(w/w)。处方条件下制备的纳米粒平均粒径为51.36 nm;平均包封率与载药量分别为98.87%和13.3%;藤黄酸纳米粒的体外释药分为两相:突释期和缓释期;急性毒性试验测得藤黄酸纳米粒的ID50为26.3mg/kg。制备的藤黄酸聚乳酸纳米粒(GA-PLA-NPs)质量稳定、分散性良好。聚乳酸可能成为藤黄酸的新型载体。  相似文献   

7.
研究低分散度壳聚糖载黄芪多糖纳米粒(LCA)对糖尿病(DM)小鼠免疫功能的影响。注射链脲佐菌素与环磷酰胺混合试剂建立DM合并免疫力低下小鼠模型,酶法制备低分散度壳聚糖,离子交联法制备低分散度壳聚糖纳米粒,超声包埋黄芪多糖制备药物对昆明小鼠灌胃,每天1次,连续30 d。ELISA法检测小鼠血清Ig M、Ig G与INF-γ的含量,碳粒廓清法测定非特异性免疫功能,耳肿胀法检测迟发型变态反应,MTT法检测脾淋巴细胞增殖率以反映细胞免疫功能。结果显示灌胃350 mg/(kg·d)LCA显著提高血清Ig M、Ig G的分泌,显著降低INF-γ表达量,增强碳粒廓清率,提高小鼠迟发型变态反应(DTH),改善脾淋巴细胞增殖反应。适当剂量的低分散度壳聚糖载黄芪多糖纳米粒能提高DM小鼠体液免疫、非特异性免疫及细胞免疫功能,且效果优于纯黄芪多糖。  相似文献   

8.
猴头菌Hericium erinaceus是一种药食同源真菌,广泛应用于治疗胃肠道疾病,可采用液态发酵技术规模化量产获得菌丝体粉。本研究旨在分析猴头发酵菌粉(HE,300mg/kg/d)与5-氨基水杨酸(5-aminosalicylic acid,5-ASA,150mg/kg/d)联用对葡聚糖硫酸钠(dextran sodium sulfate,DSS)诱导的小鼠结肠炎的治疗作用。HE和5-ASA能够减轻小鼠急性溃疡性结肠炎症状,包括减轻体重的降低率和疾病活动指数评分(DAI)。HE和5-ASA联用可以显著抑制小鼠结肠组织炎症,通过降低肿瘤坏死因子-α(Tnf-α)和白细胞介素-β(Il-β)基因的表达。此外,利用16S rRNA基因测序技术对小鼠盲肠微生物群落组成及结构进行分析。HE与5-ASA联用可以重塑肠道微生态环境,并显著提高狄氏副拟杆菌Parabacteroides distasonis相对丰度。人体粪便体外发酵结果证实HE与5-ASA可以增加P. distasonis。综上,HE与5-ASA联用可有效抑制小鼠结肠炎症水平,并调节肠道微生物,可能是通过增加P. distasonis起作用。  相似文献   

9.
光动力治疗创伤小,在恶性肿瘤治疗方面的应用已经得到了临床认可。治疗过程中需要给予光敏剂,在光照下产生分子氧对肿瘤细胞产生杀伤作用。但是,大多数光敏剂缺乏对肿瘤细胞的特异性,其在肿瘤中的富集主要与细胞高代谢有关,并且在水相媒介中溶解度比较差。纳米技术应用于光动力治疗提供了一种有效地体内运输光敏剂的方式。目前,聚合物纳米粒与光动力药物传递的研究越来越多,光敏剂通过纳米粒的运输为弥补光动力治疗的不足提供了可能,这是因为纳米载体可以将治疗浓度的光敏剂运送到肿瘤细胞而不造成非靶向组织的副损伤。本文将介绍对肿瘤光动力治疗中具有特异性的聚合物纳米粒的种类及在临床中的应用情况,为肿瘤靶向治疗提供新思路。  相似文献   

10.
目的:以BSA作为模型药物,制备壳聚糖季铵盐-OREC复合物纳米微粒,建立一种安全有效的药物控释传递系统。方法:超声条件下,制备不同质量比的具有壳聚糖硅酸盐插层结构的复合物纳米微粒,观察其形态学特征、进行红外光谱分析。同时,测定OREC对BSA包封率和载药量的影响。结果:成功制备了不同质量比的OREC-HTCC纳米粒子。电镜结果显示纳米粒呈圆球形,均匀,平均粒径约为30nm。红外图谱分析证实,HTCC插入了OREC插层中,BSA成功地包裹入HTCC-ALG/OREC混合材料制备的纳米微粒。加入OREC后,纳米粒子的包封率及载药量均明显提高,但随着加入量的增加,包封率及载药量逐渐减少。结论:OREC-HTCC纳米粒子是良好的蛋白药物载体,具有粒径小、包封率高、缓释效果好等优点,为CS-OREC作为潜在的药物给药系统的进一步应用提供科学依据。  相似文献   

11.
Mesalamine (5-aminosalicylic acid) is the drug of choice for the treatment of Crohn's disease. A scheme for the synthesis of 5-aminosalicylic acid (5-ASA) conjugates of dextrans was developed with a focus on Crohn's disease applications. Dextrans were oxidised using sodium periodate (NaIO(4)), where the aldehyde groups formed were coupled with the alpha-amino (-NH(2)) group of 5-ASA. The resulting imine bonds were unstable in water and were consequently reduced to secondary amine groups. The effects of different aspects of the conjugation reaction were studied. These included the following: the molecular weight of the dextrans, the molar proportion of NaIO(4) to the dextrans (for periodate oxidation), the pH of the conjugation solutions, the ratio 5-ASA to oxidised polysaccharide and the relationship between the degree of conjugation and the amount of enzyme hydrolysis. Conjugates incubated in HCl were stable in 0.5 and 1.0M HCl, but they underwent degradation in 2.0 and 4.0M HCl. Dextrans (MW 20,000) with various degrees of oxidation (12%, 26%, 46%, 65%, 90% and 93%) were also prepared. Each oxidised dextran sample was conjugated with 5-ASA, and the product was quantified by high-performance liquid chromatography (HPLC). Dextrans with a maximum degree of oxidation (93%) unsurprisingly gave maximum conjugation of 5-ASA (49.1mg per 100mg of product) but were resistant to dextranase hydrolysis. Less oxidised dextrans (12%) conjugated proportionally less 5-ASA (15.1mg per 100mg of product) but were successfully hydrolysed by dextranase, suggesting their potential applications for the treatment of Crohn's disease in the distal ileum and proximal colon.  相似文献   

12.
In this paper, we proposed a new method for the determination of either human serum albumin (HSA) or 5-Aminosalicylic acid (5-ASA) by synchronous fluorescence spectra and examined the interaction between them using the molecular modeling method under simulative physiological conditions. The optimum conditions of synchronous fluorometric determination of HSA were investigated and the method was successfully applied to the determination of 5-ASA added to serum, urine, and saliva samples. The linear range of the determination of HSA and 5-ASA were 1.60 – 414 μg mL−1 and 0.76 –22.95 μg mL−1, the detection limits were 0.552 μg mL−1 and 0.38 μg mL−1, respectively. In addition, the effect of various common ions on the determination of HSA with 5-ASA was also discussed at room temperature. Figure The salicylic acid moiety is located within the binding pocket. The ring of 5-ASA was inserted in the hydrophobic cavity of site I, and it is important to note that the residue ARG-218 and the trptophan residue of HSA (Trp214) are in close proximity to the ring of 5-ASA suggesting the existence of hydrophobic interaction between them.  相似文献   

13.
Poli  E.  Lazzaretti  M.  Grandi  D.  Pozzoli  C.  Coruzzi  G. 《Neurochemical research》2001,26(8-9):1085-1093
The 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced model of experimental colitis was used to investigate the time-course of alterations in enteric neurotransmission and/or smooth muscle function that occur in chronic inflammation. Myenteric plexus morphology (immunocytochemical markers), functional integrity of cholinergic neurons (3H-choline uptake, acetylcholine release and contractile response to electrical field stimulation) and smooth muscle integrity (contractile response to exogenous acetylcholine) were determined 2, 7, 15, and 30 days after TNBS treatment. In TNBS-treated rats extensive ulcerations of the mucosa and/or the submucosa and increase in colonic weights were accompanied by significant reduction in 3H-choline uptake, acetylcholine release and contractile response to stimulation of enteric nerves. These changes were maximal 7 and 15 days after TNBS treatment. Immunocytochemical marker (PGP 9.5, SNAP 25, synaptophysin and S100 protein) expression was absent in necrotic areas of colons removed 7 days post-injury and partially reduced in colons removed 15 days after TNBS treatment. By contrast, the contractile response to exogenous acetylcholine was significantly increased after 7 days in both inflamed and uninflamed regions and returned to control values by day 30. Likewise, an almost complete recovery of neural cholinergic function and of myenteric plexus morphology was observed 30 days after TNBS treatment. These data suggest that TNBS-induced colitis is associated with progressive and selective alterations in myenteric plexus structure and function, with consequent reduction of cholinergic neurotransmission and abnormality in colonic contractility. The reversibility of myenteric plexus disruption is a clear indication of neuronal plasticity within enteric nervous system as an adaptative mechanism against inflammatory challenges.  相似文献   

14.
Colonic drug delivery is intended not only for local treatment in inflammatory bowel disease (IBD) but also for systemic delivery of therapeutics. Intestinal myeloperoxidase (MPO) determination could be used to estimate the average level of inflammation in colon as well as to determine the efficacy of drugs to be used in the treatment of inflammatory bowel diseases or study the specificity of dosage forms to be used for colonic targeting of anti-inflammatory drugs. Colonic prodrug sulfasalazine (SASP) gets metabolized to give 5-aminosalicylic acid (5-ASA), which is the active portion of SASP. However, when given orally, 5-ASA is absorbed in upper part of gastrointestinal tract (GIT) and not made available in colon. In the present study, colon-targeted delivery of 5-ASA was achieved by formulating tablets with two natural polymers namely guar gum and pectin using compression coating method. Colonic specificity of 5-ASA tablets (prepared using guar gum and pectin as polymers) was evaluated in vitro using simulated fluids mimicking in vivo environment as well as in vivo method using chemically (2,4,6-trinitrobenzenesulfonic acid and acetic acid)-induced colitis rat model. Both colon-specific formulations of 5-ASA (guar gum and pectin) were observed to be more effective in reducing inflammation in chemically induced colitis rat models when compared to colon-specific prodrug sulfasalazine as well as conventional 5-ASA administered orally.KEY WORDS: colitis, colon-specific drug delivery, myeloperoxidase  相似文献   

15.
In recent years, both pharmaceutical companies and manufacturing industries have expressed heightened interest in the potential applications of magnetic nanoparticles for therapeutic and technological purposes. Specifically, pharmaceutical companies seek to employ magnetic nanoparticles as carriers to facilitate effective drug delivery, especially in areas of the brain. Manufacturing industries desire to use these nanoparticles as ferrofluids and in magnetic resonance imaging. However, data concerning the effects of magnetic nanoparticles on the nervous system is limited. This study tested the hypotheses that nanoparticles can (1) inhibit adherence of astrocytes to culture plates and (2) cause cytotoxicity or termination of growth, both end points representing surrogate markers of neurotoxicity. Using light microscopy, changes in plating patterns were determined by visual assessment. Cell counting 4 days after plating revealed a significant decrease in the number of viable astrocytes in nanoparticle treated groups (p < 0.0001). To determine the cytotoxic effects of nanoparticles, astrocytes were allowed to adhere to culture plates and grow to maturity for 3 weeks before treatment. Membrane integrity and mitochondrial function were measured using colorimetric analysis lactate dehydrogenase (LDH) and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTS), respectively. Treatment with nanoparticles did not significantly alter astrocytic LDH release (p > 0.05) in the control group (100% ± 1.56) vs the group receiving treatment (97.18% ± 2.03). However, a significant increase in MTS activity (p < 0.05) between the control (100% ± 3.65) and treated groups (112.8% ± 3.23) was observed, suggesting astrocytic mitochondrial uncoupling by nanoparticles. These data suggest that nanoparticles impede the attachment of astrocytes to the substratum. However, once astrocytes attach to the substratum and grow to confluence, nanoparticles may cause mitochondrial stress.  相似文献   

16.
目的:探讨溃愈散对溃疡性结肠炎患者血清IL-4水平的影响及临床疗效观察。方法:将60例UC患者随机分为2组,治疗组和对照组各30例,治疗组用溃愈散保留灌肠治疗,对照组口服柳氮磺吡啶治疗。采用双抗体夹心ELISA法检测2组患者治疗前后血清IL-4水平,并与30例健康志愿者(空白组)对照。结果:治疗组临床总有效率为86.7%,对照组临床总有效率为70.0%,两组总有效率比较差别无统计学意义(P〉0.05)。两组肠黏膜病变疗效相当(P〉0.05)。治疗前两组血清IL-4水平明显低于空白组(P〈0.01)。治疗组与对照组治疗前相互比较,血清IL-4水平无统计学差异,治疗后两组血清IL-4水平较治疗前均明显上升(P〈0.01),且治疗组上升程度高于对照组(P〈0.01)。结论:溃愈散对UC有良好的治疗作用并提高UC患者血清IL-4水平。  相似文献   

17.
目的:探讨同种异体骨髓单个核细胞(BM-MNCs)移植大鼠溃疡性结肠炎模型的作用。方法:将DAPI标记的同种异体大鼠骨髓单个核细胞(BM-MNCs)经尾静脉注射移植到大鼠溃疡性结肠炎(UC)模型体内(模型组),以尾静脉注射等量PBS的UC大鼠作为对照组。光镜观察大鼠结肠组织病变改变,荧光显微镜观察标记DAPI的BM-MNCs在结肠组织中的定植及分布情况,免疫荧光检测BM-MNCs中CK19、CD34的表达情况。结果:移植组大鼠结肠组织可见新生黏膜上皮及腺体,黏膜下有新鲜至成熟肉芽组织生成,明显优于对照组;移植14天,大鼠结肠组织中可观察到DAPI标记的BM-MNCs细胞;DAPI标记的细胞可表达血管内皮细胞特异性表达蛋白CD34或黏膜上皮细胞特异性表达蛋白CK19。结论:BM-MNCs可向受损病变部位结肠组织迁移和定植,且分化为血管内皮细胞和黏膜上皮细胞。  相似文献   

18.

Background & Aims

The therapeutic benefits of mesenchymal stem cells (MSCs), such as homing ability, multipotent differentiation capacity and secretion of soluble bioactive factors which exert neuroprotective, anti-inflammatory and immunomodulatory properties, have been attributed to attenuation of autoimmune, inflammatory and neurodegenerative disorders. In this study, we aimed to determine the earliest time point at which locally administered MSC-based therapies avert enteric neuronal loss and damage associated with intestinal inflammation in the guinea-pig model of colitis.

Methods

At 3 hours after induction of colitis by 2,4,6-trinitrobenzene-sulfonate (TNBS), guinea-pigs received either human bone marrow-derived MSCs, conditioned medium (CM), or unconditioned medium by enema into the colon. Colon tissues were collected 6, 24 and 72 hours after administration of TNBS. Effects on body weight, gross morphological damage, immune cell infiltration and myenteric neurons were evaluated. RT-PCR, flow cytometry and antibody array kit were used to identify neurotrophic and neuroprotective factors released by MSCs.

Results

MSC and CM treatments prevented body weight loss, reduced infiltration of leukocytes into the colon wall and the myenteric plexus, facilitated repair of damaged tissue and nerve fibers, averted myenteric neuronal loss, as well as changes in neuronal subpopulations. The neuroprotective effects of MSC and CM treatments were observed as early as 24 hours after induction of inflammation even though the inflammatory reaction at the level of the myenteric ganglia had not completely subsided. Substantial number of neurotrophic and neuroprotective factors released by MSCs was identified in their secretome.

Conclusion

MSC-based therapies applied at the acute stages of TNBS-induced colitis start exerting their neuroprotective effects towards enteric neurons by 24 hours post treatment. The neuroprotective efficacy of MSC-based therapies can be exerted independently to their anti-inflammatory effects.  相似文献   

19.

Background

Caveolin-1 (Cav-1) is a multifunctional scaffolding protein serving as a platform for the cell’s signal-transduction and playing an important role in inflammation. However, its role in inflammatory bowel disease is not clear. A recent study showed that Cav-1 is increased and mediates angiogenesis in dextran sodium sulphate-induced colitis, which are contradictory to our pilot findings in 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis. In the present study, we further clarified the role of Cav-1 in TNBS-induced colitis.

Methods

In BALB/c mice, acute colitis was induced by intra-rectal administration of one dose TNBS, while chronic colitis was induced by administration of TNBS once a week for 7 weeks. To assess the effects of complete loss of Cav-1, Cav-1 knockout (Cav-1−/−) and control wild-type C57 mice received one TNBS administration. Body weight and clinical scores were monitored. Colon Cav-1 and pro-inflammatory cytokine levels were quantified through ELISAs. Inflammation was evaluated through histological analysis.

Results

Colon Cav-1 levels were significantly decreased in TNBS-induced colitis mice when compared to normal mice and also inversely correlated with colon inflammation scores and proinflammatory cytokine levels (IL-17, IFN-γ and TNF) significantly. Furthermore, after administration of TNBS, Cav-1−/− mice showed significantly increased clinical and colon inflammatory scores and body weight loss when compared with control mice.

Conclusions and Significance

Cav-1 may play a protective role in the development of TNBS-induced colitis. Our findings raise an important issue in the evaluation of specific molecules in animal models that different models may exhibit opposite results because of the different mechanisms involved.  相似文献   

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