Dendrimers

树枝状聚合物
  • 文章类型: Journal Article
    改善纳米医学的临床翻译需要更好地了解纳米颗粒如何与生物环境相互作用。随着研究人员认识到理解蛋白质电晕和表征纳米载体在生物系统中反应的重要性,需要新的工具和技术来分析纳米载体-蛋白质相互作用,特别是对于较小尺寸(<10nm)的纳米颗粒,如聚酰胺胺(PAMAM)树枝状聚合物。这里,我们开发了一个流线型的,半定量方法使用非变性电泳技术结合质谱来评估树枝状聚合物-蛋白质相互作用。有了这个协议,我们同时检测荧光标记的树枝状聚合物和蛋白质,使我们能够分析树枝状聚合物何时随蛋白质迁移。我们发现PAMAM树枝状聚合物主要与补体蛋白相互作用,特别是C3和C4a,与以前发布的数据一致,验证我们的方法可用于分离和鉴定树枝状聚合物-蛋白质相互作用。
    Improving the clinical translation of nanomedicine requires better knowledge about how nanoparticles interact with biological environments. As researchers are recognizing the importance of understanding the protein corona and characterizing how nanocarriers respond in biological systems, new tools and techniques are needed to analyze nanocarrier-protein interactions, especially for smaller size (<10 nm) nanoparticles like polyamidoamine (PAMAM) dendrimers. Here, we developed a streamlined, semiquantitative approach to assess dendrimer-protein interactions using a nondenaturing electrophoresis technique combined with mass spectrometry. With this protocol, we detect fluorescently tagged dendrimers and proteins simultaneously, enabling us to analyze when dendrimers migrate with proteins. We found that PAMAM dendrimers mostly interact with complement proteins, particularly C3 and C4a, which aligns with previously published data, verifying that our approach can be used to isolate and identify dendrimer-protein interactions.
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  • 文章类型: Journal Article
    拓扑指数为捕获分子结构提供了一种数学语言,对称性,并预测属性。树枝状聚合物是微观的双侧对称分子,具有明确的均质纳米颗粒结构,通常由一个对称中心组成,内壳,和外壳。在这项工作中,首先,我们计算卟啉(DnPn)的一些基于度的拓扑指数,聚丙醚亚胺(PETIM),锌卟啉(DPZn),和聚酰胺胺(PAMAM)树枝状聚合物。然后,我们使用多准则决策(MCDM)技术来建立基于某些拓扑指数的树枝状聚合物类的加权评估。对于加权分析,我们将苯衍生物的性质与拓扑不变量相关联。最后,基于多准则决策技术,即TOPSIS,SAW和MOORA方法,我们根据树枝状聚合物的性质对它们进行了排序。
    Topological indices provide a mathematical language for capturing molecular structure, symmetry, and predicting properties. Dendrimers are microscopic bilaterally symmetrical molecules with a well-defined homogeneous nanoparticles structure, often consisting of a symmetric center, inner shell, and outer shell. In this work, first we compute some degree-based topological indices of Porphyrin (DnPn),Poly (Propyl) Ether Imine(PETIM), Zinc porphyrin (DPZn), and Polyamidoamine (PAMAM) dendrimers. Then, we use multi-criteria decision making (MCDM) techniques to establish the weighted evaluation of dendrimer classes based on certain topological indices. For weighted analysis we correlate the properties of benzene derivatives with topological invariants. Finally, based on the multi-criteria decision making techniques namely TOPSIS, SAW and MOORA method, we have ranked the dendrimer structures based on their properties.
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  • 文章类型: Journal Article
    抗菌素耐药性是一个严重的公共卫生问题,微生物形成生物膜的能力加剧了这种情况。因此,需要找到新的治疗策略,其中之一是使用阳离子树枝状系统(树枝状聚合物和树突)。
    本研究的目的是分析六种阳离子碳硅烷(CBS)树枝状聚合物和一个具有外周铵基团的树突对多药耐药细菌的体外抗菌功效,其中一些是分离的医院菌株,和他们的生物膜。为此,最小抑制浓度(MIC),最小杀菌浓度(MBC),进行了最小生物膜抑制浓度(MBIC)和最小根除生物膜浓度(MBEC)研究。此外,分析了那些被证明是最有效的化合物对Hela细胞的细胞毒性。
    所有测试的化合物都显示出针对耐甲氧西林金黄色葡萄球菌的浮游形式的体外活性,仅树枝状聚合物BDSQ017,BDAC-001和BDLS-001以及树突BDEF-130针对其生物膜。另一方面,只有树枝状聚合物BDAC001,BDLS-001和BDJS-049和树突BDEF-130在体外对多药耐药的铜绿假单胞菌的浮游形式具有抗菌作用,但是他们缺乏对预先形成的生物膜的活性。此外,树枝状聚合物BDAC-001,BDLS-001和BDSQ-017以及树突BDEF-130在体外表现出良好的细胞毒性。
    我们的研究证明了使用上述四种化合物作为针对多药耐药细菌的临床和参考菌株的可能的局部抗微生物剂的可能性。
    Antimicrobial Resistance is a serious public health problem, which is aggravated by the ability of the microorganisms to form biofilms. Therefore, new therapeutic strategies need to be found, one of them being the use of cationic dendritic systems (dendrimers and dendrons).
    The aim of this study is to analyze the in vitro antimicrobial efficacy of six cationic carbosilane (CBS) dendrimers and one dendron with peripheral ammonium groups against multidrug-resistant bacteria, some of them isolated hospital strains, and their biofilms. For this purpose, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and minimum eradication biofilm concentration (MBEC) studies were carried out. In addition, the cytotoxicity on Hela cells of those compounds that proved to be the most effective was analyzed.
    All the tested compounds showed in vitro activity against the planktonic forms of methicillin-resistant Staphylococcus aureus and only the dendrimers BDSQ017, BDAC-001 and BDLS-001 and the dendron BDEF-130 against their biofilms. On the other hand, only the dendrimers BDAC 001, BDLS-001 and BDJS-049 and the dendron BDEF-130 were antibacterial in vitro against the planktonic forms of multidrug-resistant Pseudomonas aeruginosa, but they lacked activity against their preformed biofilms. In addition, the dendrimers BDAC-001, BDLS-001 and BDSQ-017 and the dendron BDEF-130 exhibited a good profile of cytotoxicity in vitro.
    Our study demonstrates the possibility of using the four compounds mentioned above as possible topical antimicrobials against the clinical and reference strains of multidrug-resistant bacteria.
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  • 文章类型: Journal Article
    两种不同的二氧化硅构象(干凝胶和纳米颗粒),两者都是由树枝状聚(乙烯亚胺)介导形成的,在低pH下测试了有问题的铀酰阳离子吸附。关键因素的影响,即,温度,静电力,吸附剂组合物,污染物对树枝状腔的可及性,和有机基质的MW,进行了研究,以确定在这些条件下水净化的最佳配方。这是借助紫外可见光谱和FTIR光谱实现的,动态光散射(DLS),ζ-电位,液氮(LN2)孔隙率法,热重分析(TGA),和扫描电子显微镜(SEM)。结果强调两种吸附剂都具有非凡的吸附能力。干凝胶具有成本效益,因为它们的性能接近有机含量少得多的纳米颗粒。两种吸附剂都可以以分散体的形式使用。干凝胶,虽然,是更实用的材料,因为它们可以前体凝胶形成溶液的形式穿透金属或陶瓷固体基底的孔,生产复合净化装置。
    Two different silica conformations (xerogels and nanoparticles), both formed by the mediation of dendritic poly (ethylene imine), were tested at low pHs for problematic uranyl cation sorption. The effect of crucial factors, i.e., temperature, electrostatic forces, adsorbent composition, accessibility of the pollutant to the dendritic cavities, and MW of the organic matrix, was investigated to determine the optimum formulation for water purification under these conditions. This was attained with the aid of UV-visible and FTIR spectroscopy, dynamic light scattering (DLS), ζ-potential, liquid nitrogen (LN2) porosimetry, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Results highlighted that both adsorbents have extraordinary sorption capacities. Xerogels are cost-effective since they approximate the performance of nanoparticles with much less organic content. Both adsorbents could be used in the form of dispersions. The xerogels, though, are more practicable materials since they may penetrate the pores of a metal or ceramic solid substrate in the form of a precursor gel-forming solution, producing composite purification devices.
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  • 文章类型: Journal Article
    在这篇文章中,我们使用Scheutjens-Fleer的数值自洽场方法研究了杂合分子的胶束化,该杂合分子由一个带有带电端基的聚赖氨酸树突和几个附着在其根上的线性疏水尾巴组成。主要注意球形胶束以及确定它们可能出现的参数范围。已在所得球形胶束的大小和内部结构与疏水尾部的长度和数量之间建立了关系,以及dendron世代的数量。表明,将相同数量的疏水单体从一个长尾分裂成几个短尾导致聚集数减少,并且因此,胶束中终端电荷的数量。同时,研究表明,每个树枝的表面积不取决于杂化分子中疏水单体或尾部的数量。还研究了杂化分子结构与所得胶束的静电性质之间的关系。发现电晕中的电荷分布取决于杂化分子中树突代G的数量。对于少数世代(G=3),观察到标准的双电层。对于更多的世代(G=4),日冕中树突的电荷分为两个种群:在第一个种群中,电荷位于胶束核和壳之间边界附近的球形层中,在第二人口中,电荷靠近球形壳的外围。因此,抗衡离子的一部分位于它们之间的广阔区域中。这些结果对于使用球形树状胶束作为用于药物递送的纳米容器具有潜在的兴趣。
    In this article, we used the numerical self-consistent field method of Scheutjens-Fleer to study the micellization of hybrid molecules consisting of one polylysine dendron with charged end groups and several linear hydrophobic tails attached to its root. The main attention was paid to spherical micelles and the determination of the range of parameters at which they can appear. A relationship has been established between the size and internal structure of the resulting spherical micelles and the length and number of hydrophobic tails, as well as the number of dendron generations. It is shown that the splitting of the same number of hydrophobic monomers from one long tail into several short tails leads to a decrease in the aggregation number and, accordingly, the number of terminal charges in micelles. At the same time, it was shown that the surface area per dendron does not depend on the number of hydrophobic monomers or tails in the hybrid molecule. The relationship between the structure of hybrid molecules and the electrostatic properties of the resulting micelles has also been studied. It is found that the charge distribution in the corona depends on the number of dendron generations G in the hybrid molecule. For a small number of generations (up to G=3), a standard double electric layer is observed. For a larger number of generations (G=4), the charges of dendrons in the corona are divided into two populations: in the first population, the charges are in the spherical layer near the boundary between the micelle core and shell, and in the second population, the charges are near the periphery of the spherical shell. As a result, a part of the counterions is localized in the wide region between them. These results are of potential interest for the use of spherical dendromicelles as nanocontainers for drug delivery.
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  • 文章类型: Journal Article
    制备了具有中心四苯基甲烷和外围3,5-二-(叔丁酰基氨基)苯甲酰基哌嗪部分的两个树枝状聚合物的合理产率。这些树枝状聚合物在固态下具有空隙空间,因此它们吸附客体分子。他们的BET值各不相同,取决于外围部分和气体分子之间的H键相互作用,构成空隙空间的树枝状框架是柔性的。在极性气体分子如CO2的存在下,BET显著增加并且是N2下BET的约4-8倍。一种树枝状聚合物吸附氰基苯的水平为436mg/g,which,对于作者最好的知识,几乎相当于文献中的最高报道值。
    Reasonable yields of two dendrimers with central tetraphenylmethane and peripheral 3,5-di-(tert-butanoylamino)benzoylpiperazine moieties are prepared. These dendrimers have a void space in the solid state so they adsorb guest molecules. Their BET values vary, depending on the H-bond interaction between the peripheral moiety and the gas molecules, and the dendritic framework that fabricates the void space is flexible. In the presence of polar gas molecules such as CO2, the BET increases significantly and is about 4-8 times the BET under N2. One dendrimer adsorbs cyanobenzene to a level of 436 mg/g, which, to the authors\' best knowledge, is almost equivalent to the highest reported value in the literature.
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  • 文章类型: Journal Article
    由SARS-CoV-2引发的过度炎症是疾病严重程度的主要原因,激活的巨噬细胞参与了这种反应。OP-101,一种羟基聚酰胺胺树状聚合物-N-乙酰半胱氨酸缀合物,特异性靶向活化的巨噬细胞,改善全身炎症和神经炎症的临床前模型的结局.在这个多中心,随机化,双盲,安慰剂对照,适应阶段2a试验,我们评估了OP-101在重症COVID-19患者中的安全性和初步疗效。24名被归类为重度COVID-19且基线世界卫生组织七点序数量表≥5的患者被随机分配接受单次静脉给药安慰剂(n=7名患者)或OP-101(n=6),4(n=6),或8mg/kg(n=5名患者)。所有研究参与者都接受了标准护理,包括皮质类固醇.4mg/kg的OP-101在降低炎症标志物方面优于安慰剂;4和8mg/kg的OP-101在降低神经损伤标志物方面优于安慰剂,(神经丝轻链和神经胶质原纤维酸性蛋白)。治疗后30天和60天机械通气或死亡的复合结局的风险为71%(95%CI:29%,安慰剂为96%)和18%(95%CI:4%,43%;P=0.021),用于合并的OP-101治疗组。在60天,给予安慰剂的7例患者中有3例存活,接受OP-101治疗的17例患者中有14例存活。未报告与药物相关的不良事件。这些数据表明,OP-101具有良好的耐受性,可能具有治疗全身性炎症和神经元损伤的潜力。降低重症COVID-19住院患者的发病率和死亡率。
    Hyperinflammation triggered by SARS-CoV-2 is a major cause of disease severity, with activated macrophages implicated in this response. OP-101, a hydroxyl-polyamidoamine dendrimer-N-acetylcysteine conjugate that specifically targets activated macrophages, improves outcomes in preclinical models of systemic inflammation and neuroinflammation. In this multicenter, randomized, double-blind, placebo-controlled, adaptive phase 2a trial, we evaluated safety and preliminary efficacy of OP-101 in patients with severe COVID-19. Twenty-four patients classified as having severe COVID-19 with a baseline World Health Organization seven-point ordinal scale of ≥5 were randomized to receive a single intravenous dose of placebo (n = 7 patients) or OP-101 at 2 (n = 6), 4 (n = 6), or 8 mg/kg (n = 5 patients). All study participants received standard of care, including corticosteroids. OP-101 at 4 mg/kg was better than placebo at decreasing inflammatory markers; OP-101 at 4 and 8 mg/kg was better than placebo at reducing neurological injury markers, (neurofilament light chain and glial fibrillary acidic protein). Risk for the composite outcome of mechanical ventilation or death at 30 and 60 days after treatment was 71% (95% CI: 29%, 96%) for placebo and 18% (95% CI: 4%, 43%; P = 0.021) for the pooled OP-101 treatment arms. At 60 days, 3 of 7 patients given placebo and 14 of 17 OP-101-treated patients were surviving. No drug-related adverse events were reported. These data show that OP-101 was well tolerated and may have potential to treat systemic inflammation and neuronal injury, reducing morbidity and mortality in hospitalized patients with severe COVID-19.
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  • 文章类型: Journal Article
    Astodrimer钠是一种树枝状分子,在体外对SARS-CoV-2和其他呼吸道病毒具有抗病毒和杀病毒活性,以前被证明是安全的,耐受性良好,而不是系统吸收,当应用于阴道粘膜时。为了研究其作为局部抗病毒的潜在效用,在暴露于呼吸道感染之前或之后,已将钠重新配制用于鼻粘膜,以帮助减少病毒载量。目前的调查评估了安全性,1%抗病毒鼻喷雾剂的耐受力和吸收。这是一个单一的中心,双盲,随机化,安慰剂对照,探索性临床调查。在澳大利亚的临床试验机构中,将40名年龄在18至65岁之间,没有临床上显着的鼻腔检查结果的健康志愿者随机分为3:1,分别接受阿托德默钠鼻喷雾剂(N=30)或安慰剂(N=10)。最初的一组参与者(N=12,N=4安慰剂)接受单次应用(每个鼻孔一次喷雾)以评估任何急性影响,接下来是一个冲洗期,在自我施用喷雾剂之前,每天四次,共14天,以代表密集的应用时间表。在该队列中还评估了通过鼻粘膜吸收钠的程度。第二组参与者(N=18岁,N=6安慰剂)每天四次自我施用喷雾剂,共14天。主要终点是安全性,通过治疗紧急不良事件(TEAE)的频率和严重程度来衡量,包括有临床意义的鼻腔检查结果,在安全性人群中(所有接受任何喷雾剂的参与者)。参与者在2021年1月6日至2021年3月29日之间进行随机分组。TEAE发生在安慰剂组的8/10(80%)参与者和钠钠组的19/30(63.3%)参与者中;都是轻度的。被认为与研究产品潜在相关的TEAE发生在5/10(50%)接受安慰剂的参与者和10/30(33.3%)接受钠的参与者中。没有参与者经历严重的AE,或TEAE导致退出研究。未检测到通过鼻粘膜的钠的全身吸收。Astodrimer钠鼻喷雾剂具有良好的耐受性,是一项有前途的创新,需要对鼻腔给药进行进一步研究,以可能减少社区获得性呼吸道病毒感染的感染和传播。试验注册:ACTRN12620001371987,首次注册22-12-2020(澳大利亚新西兰临床试验注册,https://anzctr.org。au/).
    Astodrimer sodium is a dendrimer molecule with antiviral and virucidal activity against SARS-CoV-2 and other respiratory viruses in vitro, and has previously been shown to be safe and well tolerated, and not systemically absorbed, when applied to the vaginal mucosa. To investigate its potential utility as a topical antiviral, astodrimer sodium has been reformulated for application to the nasal mucosa to help reduce viral load before or after exposure to respiratory infection. The current investigation assessed the safety, tolerability and absorption of astodrimer sodium 1% antiviral nasal spray. This was a single-centre, double-blinded, randomized, placebo-controlled, exploratory clinical investigation. Forty healthy volunteers aged 18 to 65 years with no clinically significant nasal cavity examination findings were randomized 3:1 to astodrimer sodium nasal spray (N = 30) or placebo (N = 10) at an Australian clinical trials facility. An initial cohort of participants (N = 12 astodrimer, N = 4 placebo) received a single application (one spray per nostril) to assess any acute effects, followed by a washout period, before self-administering the spray four times daily for 14 days to represent an intensive application schedule. Extent of absorption of astodrimer sodium via the nasal mucosa was also assessed in this cohort. A second cohort of participants (N = 18 astodrimer, N = 6 placebo) self-administered the spray four times daily for 14 days. The primary endpoint was safety, measured by frequency and severity of treatment emergent adverse events (TEAEs), including clinically significant nasal cavity examination findings, in the safety population (all participants randomized who administered any spray). Participants were randomized between 6 January 2021 and 29 March 2021. TEAEs occurred in 8/10 (80%) participants in the placebo arm and 19/30 (63.3%) participants in the astodrimer sodium arm; all were of mild intensity. TEAEs considered potentially related to study product occurred in 5/10 (50%) participants receiving placebo and 10/30 (33.3%) of participants receiving astodrimer sodium. No participants experienced serious AEs, or TEAEs leading to withdrawal from the study. No systemic absorption of astodrimer sodium via the nasal mucosa was detected. Astodrimer sodium nasal spray was well tolerated and is a promising innovation warranting further investigation for nasal administration to potentially reduce infection and spread of community acquired respiratory virus infections.Trial Registration: ACTRN12620001371987, first registered 22-12-2020 (Australia New Zealand Clinical Trials Registry, https://anzctr.org.au/ ).
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  • 文章类型: Journal Article
    Galectins are galactoside-binding lectins that are functional dimers or higher-order oligomers. Multivalent binding has been shown to augment the relatively low affinity of the galectins for their galactoside-binding partners, enabling the galectins to play an important role in the global remodeling of cells that occurs during the stress conditions of disease states, including heart disease and cancer. The presence of galectins in the nematode Caenorhabditis elegans and their galactoside-binding properties have been demonstrated, but the role of multivalent interactions for C. elegans galectins is unknown. Here, we describe the synthesis of Galβ1-4Fuc-functionalized poly(amidoamine) dendrimers and their utility in studies using C. elegans during oxidative stress. C. elegans were fed Galβ1-4Fuc-functionalized dendrimers and RNA interference to knock down lectins lec-1 and lec-10 while undergoing oxidative stress. C. elegans that were pretreated with the glycodendrimers were less susceptible to oxidative stress than untreated controls. Worms that were fed fluorescently tagged glycodendrimers and imaged indicated that the dendrimers are primarily present in the digestive tract of the worms, and uptake into the vulva and proximal gonads could also be observed in some instances. This study suggests that multivalently presented Galβ1-4Fuc can protect C. elegans from oxidative stress.
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  • 文章类型: Journal Article
    发展纳米制剂作为有效药物递送系统的主要障碍是从血液循环和溶酶体截留的快速清除。为了克服这些问题,构建基于多糖的核-壳型电荷可转换纳米制剂(CS-LA-DMMA/CMCS/PAMAM@DOX)以提高DOX的抗肿瘤功效。通过应用羧甲基壳聚糖(CMCS)作为桥聚合物和带负电荷的壳聚糖衍生物作为外壳,该纳米制剂的稳定性和pH敏感性有望增强。此外,带正电荷的PAMAM@DOX可以通过“质子海绵效应”和“阳离子-阴离子与溶酶体膜的相互作用”从溶酶体中逸出。在这项研究中检测到令人钦佩的细胞摄取和高的凋亡/坏死率。体外测定表明CS-LA-DMMA/CMCS/PAMAM@DOX主要通过网格蛋白介导的内吞途径内化到HepG2细胞中。令人兴奋的是,体内研究表明,CS-LA-DMMA/CMCS/PAMAM@DOX在肿瘤组织中的高积累导致肿瘤抑制增强。与免费DOX相比,纳米制剂的抑瘤率提高到226%。
    Major obstacles in the development of nanoformulations as efficient drug delivery systems are the rapid clearance from blood circulation and lysosomal entrapment. To overcome these problems, a polysaccharide-based core-shell type charge-switchable nanoformulation (CS-LA-DMMA/CMCS/PAMAM@DOX) is constructed to improve antitumor efficacy of DOX. By applying carboxymethyl chitosan (CMCS) as bridge polymer and negatively charged chitosan-derivative as outer shell, the stability and pH-sensitivity of this nanoformulation is promisingly enhanced. Furthermore, the positively charged PAMAM@DOX could escape from lysosomes via \"proton sponge effect\" and \"cationic-anionic interaction with lysosome membranes\". Admirable cellular uptake and high apoptosis/necrosis rate were detected in this study. In vitro assays demonstrate that the CS-LA-DMMA/CMCS/PAMAM@DOX was internalized into HepG2 cells predominantly via the clathrin-mediated endocytosis pathway. Excitingly, in vivo studies showed that high accumulation of CS-LA-DMMA/CMCS/PAMAM@DOX in tumor tissue led to enhanced tumor inhibition. Compared with free DOX, the tumor inhibition rate of nanoformulation was improved up to 226%.
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