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1.
Magdalena Markowicz Pawe? Szymański Marcin Ciszewski Arkadiusz K?ys El?bieta Mikiciuk-Olasik 《Journal of biological physics》2012,38(4):637-656
The interactions between dendrimers and different types of drugs are nowadays one of the most actively investigated areas of the pharmaceutical sciences. The interactions between dendrimers and drugs can be divided into: internal encapsulation, external electrostatic interaction, and covalent conjugation. In the present study, we investigated the potential of poly(amidoamine) (PAMAM) dendrimers for solubility of four iminodiacetic acid derivatives. We reported that PAMAM dendrimers contribute to significant solubility enhancement of iminodiacetic acid analogues. The nature of the dendrimer–drug complexes was investigated by 1H NMR and 2D-NOESY spectroscopy. The 1H NMR analysis proved that the water-soluble supramolecular structure of the complex was formed on the basis of ionic interactions between terminal amine groups of dendrimers and carboxyl groups of drug molecules, as well as internal encapsulation. The 2D-NOESY analysis revealed interactions between the primary amine groups of PAMAM dendrimers and the analogues of iminodiacetic acid. The results of solubility studies together with 1H NMR and 2D-NOESY experiments suggest that the interactions between PAMAM dendrimers of generation 1–4 and derivatives of iminodiacetic acid are based on electrostatic interactions and internal encapsulation. 相似文献
2.
Jonathan Gardiner Sally Freeman Matthew Leach Alison Green Jacqui Alcock 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):623-628
Many oral care products incorporate an antibacterial compound to prevent the formation of dental plaque which predisposes teeth to dental caries or periodontal disease []. Triclosan (TCN) is a commonly used antiplaque agent in toothpastes []. Strategies to increase the delivery efficiency of antibacterials using formulation aids such as polyamidoamine (PAMAM) dendrimers are of interest.Solubilisation studies over the pH range 5-12 demonstrated an increase in the level of TCN solubilised with increasing dendrimer concentration (1 mM–5 mM). However, the dendrimer was unable to enhance TCN solubility at lower pH values and the solubilising effect observed was attributed to the ionization of TCN (pKa 8.14) resulting from dendrimer induced pH changes.End group modification of G3 PAMAM dendrimer with phenylalanine in order to promote solubility through π–π stacking between TCN and the amino acid has been carried out. Phenylalanine:G3 PAMAM conjugates of different ratios (32:1, 21:1, 16:1) were synthesized. The fully conjugated dendrimer (32:1) had poor aqueous solubility, whereas the 21:1 and 16:1 dendrimer conjugates were water soluble. The 21:1 conjugate was tested for its ability to solubilise TCN, however, again there was no increase over control buffer solutions of the same pH. An alternative approach under investigation is to directly conjugate TCN to PAMAM dendrimers via a hydrolysable linkage. 相似文献
3.
In this study, the host-guest behavior of poly(amidoamine) (PAMAM) dendrimers bearing amine, hydroxyl, or carboxylate surface functionalities were investigated by paramagnetic NMR studies. 2,2,6,6-Tetramethylpiperidinyloxy (TEMPO) derivatives were used as paramagnetic guest molecules. The results showed that TEMPO-COOH significantly broaden the 1H NMR peaks of amine- and hydroxyl-terminated PAMAM dendrimers. In comparison, no paramagnetic relaxation enhancement (PRE) was observed between TEMPO-NH2, TEMPO-OH and the three types of PAMAM dendrimers. The PRE phenomenon observed is correlated with the encapsulation of TEMPO-COOH within dendrimer pockets. Protonation of the tertiary amine groups within PAMAM dendrimers plays an important role during this process. Interestingly, the absence of TEMPO-COOH encapsulation within carboxylate-terminated PAMAM dendrimer is observed due to the repulsion of TEMPO-COO- anion and anionic dendrimer surface. The combination of paramagnetic probes and 1H NMR linewidth analysis can be used as a powerful tool in the analysis of dendrimer-based host-guest systems. 相似文献
4.
Liang Dai Dapeng Wei Jidong Zhang Tianyu Shen Yuming Zhao Junqiang Liang Wangteng Ma Limin Zhang Qingli Liu Yue Zheng 《Cell proliferation》2021,54(11)
ObjectivesIt is imperative to develop efficient strategies on the treatment of prostate cancer. Here, we constructed multifunctional nanoparticles, namely AS1411@MPDA‐DTX (AMD) for targeted and synergistic chemotherapy/photothermal therapy of prostate cancer.Materials and MethodsMesoporous polydopamine (MPDA) nanoparticles were prepared by a one‐pot synthesis method, DTX was loaded through incubation, and AS1411 aptamer was modified onto MPDA by the covalent reaction. The prepared nanoparticles were characterized by ultra‐micro spectrophotometer, Fourier transform infrared spectra, transmission electron microscope, and so on. The targeting ability was detected by selective uptake and cell killing. The mechanism of AMD‐mediated synergistic therapy was detected by Western blot and immunofluorescence.ResultsThe prepared nanoparticles can be easily synthesized and possessed excellent water solubility, stability, and controlled drug release ability, preferentially in acidic context. Based on in vitro and in vivo results, the nanoparticles can efficiently target prostate cancer cells, promote DTX internalization, and enhance the antitumor effects of chemo‐photothermal therapy strategies under the NIR laser irradiation.ConclusionsAs a multifunctional nanoplatform, AS1411@MPDA‐DTX could efficiently target prostate cancer cells, promote DTX internalization, and synergistically enhance the antiprostate cancer efficiency by combining with NIR irradiation. 相似文献
5.
L. Pe?a M. Ikenberry B. Ware K. L. Hohn D. Boyle X. S. Sun D. Wang 《Biotechnology and Bioprocess Engineering》2011,16(6):1214-1222
Mineral acids have been used effectively for the pretreatment of cellulosic biomass to improve sugar recovery and promote
its conversion to ethanol; however, substantial capital investment is required to enable separation of the acid, and corrosion-resistant
materials are necessary. Disposal and neutralization costs are also concerns because they can decrease the economic feasibility
of the process. In this work, three acid-functionalized nanoparticles were synthesized for pretreatment and hydrolysis of
lignocellulosic biomass. Silica-protected cobalt spinel ferrite nanoparticles were functionalized with perfluoroalkylsulfonic
acid (PFS), alkylsulfonic acid (AS), and butylcarboxylic acid (BCOOH) groups. These nanoparticles were magnetically separated
from the reaction media and reused. TEM images showed that the average diameter was 2 nm for both PFS and BCOOH nanoparticles
and 7 nm for AS nanoparticles. FTIR confirmed the presence of sulfonic and carboxylic acid functional groups. Ion exchange
titration measurements yielded 0.9, 1.7, and 0.2 mmol H+/g of catalyst for PFS, AS, and BCOOH nanoparticles, respectively. Elemental analysis results indicated that PFS and AS nanoparticles
had 3.1 and 4.9% sulfur, respectively. Cellobiose hydrolysis was used as a model reaction to evaluate the performance of acid-functionalized
magnetic nanoparticles for breaking β-(1→4) glycosidic bonds. Cellobiose conversion of 78% was achieved when using AS nanoparticles
as the catalyst at 175°C for 1 h, which was significantly higher than the conversion for the control experiment (52%). AS
nanoparticles retained more than 60% of their sulfonic acids groups after the first run, and 65 and 60% conversions were obtained
for the second and third runs, respectively. 相似文献
6.
Development of efficient and safe gene carrier is the main hurdle for successful gene therapy till date. Poor water solubility and low transfection efficiency of chitosan are the main drawbacks to be efficient gene carrier for successful gene therapy. In this work, PAMAM conjugated chitosan was prepared through naphthalimide moiety by simple substitution reaction. The synthesis of the chitosan conjugates was confirmed by FTIR, 1H NMR and XRD analyses. The conjugates showed enhanced DNA binding capability compared to that of unmodified chitosan. Moreover, the conjugates showed minimal cytotoxicity compared to that of polyethyleneimine (PEI, 25 kDa) and also showed good blood compatibility with negligible haemolysis. The transfection efficiency of the conjugate was significantly increased compared to that of unmodified chitosan and it also surpassed the transfection efficiency by PEI. Therefore, PAMAM conjugated chitosan can be used safely as alternate efficient gene delivery vector in gene therapy. 相似文献
7.
Gardiner J Freeman S Leach M Green A Alcock J D'Emanuele A 《Journal of enzyme inhibition and medicinal chemistry》2008,23(5):623-628
Many oral care products incorporate an antibacterial compound to prevent the formation of dental plaque which predisposes teeth to dental caries or periodontal disease. Triclosan (TCN) is a commonly used antiplaque agent in toothpastes. Strategies to increase the delivery efficiency of antibacterials using formulation aids such as polyamidoamine (PAMAM) dendrimers are of interest. Solubilisation studies over the pH range 5-12 demonstrated an increase in the level of TCN solubilised with increasing dendrimer concentration (1 mM-5 mM). However, the dendrimer was unable to enhance TCN solubility at lower pH values and the solubilising effect observed was attributed to the ionization of TCN (pKa 8.14) resulting from dendrimer induced pH changes. End group modification of G3 PAMAM dendrimer with phenylalanine in order to promote solubility through pi-pi stacking between TCN and the amino acid has been carried out. Phenylalanine:G3 PAMAM conjugates of different ratios (32:1, 21:1, 16:1) were synthesized. The fully conjugated dendrimer (32:1) had poor aqueous solubility, whereas the 21:1 and 16:1 dendrimer conjugates were water soluble. The 21:1 conjugate was tested for its ability to solubilise TCN, however, again there was no increase over control buffer solutions of the same pH. An alternative approach under investigation is to directly conjugate TCN to PAMAM dendrimers via a hydrolysable linkage. 相似文献
8.
Spectroscopic and molecular modeling studies of the interaction between morin and polyamidoamine dendrimer
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Interactions between the polyamidoamine (PAMAM) dendrimer and drug molecules are of interest for their potential biomedical applications. The goal of this work is to examine the interaction of PAMAM‐C12 25% dendrimer with morin. The ultraviolet–visible, fluorescence spectroscopic methods as well as molecular modeling were used to analyze drug‐binding mode, binding constants and binding sites, etc. The experimental data showed that the binding constant of morin‐PAMAM‐C12 25% is about 105 L/mol. The interaction of morin with PAMAM‐C12 25% is mainly driven by the hydrophobic, electrostatic, hydrogen bonds and van der Waals forces. There are mainly three classes of binding site of morin at the interface of PAMAM‐C12 25%. These results provided some useful information for self‐assembling and disassembling the PAMAM dendrimer as well as efficient drug delivery and therapeutic applications. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
In this work, a novel thiol aromatic aldehyde was synthesized. It can be used as a substrate to directly immobilize antibodies on a gold electrode, for which no additional chemical cross-linker is required. It was also applied as a linker to prepare Fe3O4@Au/PAMAM/Ab2–horseradish peroxidase bioconjugates, which introduced multiple enzymes onto a sensing interface owing to the high surface-to-volume ratio of Fe3O4@Au nanoparticles and many functional groups of the poly(amidoamine) dendrimer (PAMAM). The introduced multiple enzymes greatly improved the detection signal. Under optimal conditions, the proposed electrochemical immunosensor exhibited desirable performance for detection of IgG in the range 0.005–50 ng ml−1 with a detection limit of 3 pg ml−1 based on a signal-to-noise ratio of 3. It has great potential application in the area of clinical analysis. 相似文献
10.
P. Chanphai 《Journal of biomolecular structure & dynamics》2018,36(7):1918-1924
We report the loading efficacy of folic acid (FA) by polyamidoamine (PAMAM-G3 and PAMAM-G4) nanoparticles in aqueous solution at physiological pH. Thermodynamic parameters ΔH = ?47.57 (kJ Mol?1), ΔS = ?122.78 (J Mol?1, K?1) and ΔG = ?10.96 (kJ Mol?1) showed FA-PAMAM bindings occur via H-bonding and van der Waals contacts. The stability of acid-PAMAM conjugate increased as polymer size increased. The acid loading efficacy was 40 to 50%. TEM images exhibited major polymer morphological changes upon acid encapsulation. PAMAM dendrimers are capable of FA delivery in vitro. 相似文献
11.
The objective of this study was to determine the effect of ethylenediamine core PAMAM dendrimers, on the release of nifedipine
suspended in aqueous gels and to correlate release to the increase in solubility afforded by the dendrimers. Drug release
from aqueous 5% HPMC gels containing nifedipine (2% wt/vol) through 0.2-μm membranes was measured using Enhancer cells and
50% ethanolic solution as the receptor medium. The release from gels containing PAMAM G-3 and G-5 (0.25%–1% wt/vol) was compared
with gels containing the cosolvent isopropyl alcohol (10%–80% vol/vol). PAMAM dendrimers significantly increased the solubility
of nifedipine. This caused a significant increase in the release rate of nifedipine from the gel suspensions. The increase
in drug release depended on the concentration and generation size of the dendrimers added. For higher generations (G-5) lower
concentrations were needed to obtain equivalent increases in release. Although the increase in solubility and release was
not as high as from gels containing high concentrations of the cosolvent isopropyl alcohol, the dendrimers prevented the recrystallization
of the drug that was observed when the gels containing isopropyl alcohol were left open.
Published: October 24, 2005 相似文献
12.
Heba F. Salem Rasha M. Kharshoum Lekaa F. Abdel Hakim Mohamed E. Abdelrahim 《Journal of liposome research》2016,26(4):324-335
Purpose: Voriconazole has both low aqueous solubility and stability. We hypothesize that designing voriconazole in the form of a nano powder inhaler at a geometric diameter within 1–5?μm will enhance its stability and solubility. Therefore, we prepared nanoagglomerates of voriconazole which will collapse in the lungs to reform the nanoparticles.Method: The nanoparticles were formulated using both stearic acid and sodium deoxycholate as edge activators. Osmogenic polycation polyethyleneimine (PEI) was used to form agglomerates of controllable size.Results: Voriconazole nanoparticles and agglomerates showed a significant higher cumulative drug release than the pure powder (p?0.05) with R2?=?0.95. Small-sized particles were formed (353?nm), while their zeta potential was ?30.7?mV. The agglomerates were 2.7?μm in size and their zeta potential was ?20.9?mV. The formation of porous agglomerates was confirmed using a transmission electron microscope. Cascade impactor was used to evaluate the aerodynamic properties of the nanoparticles and the agglomerates. The aerodynamic characterization of the nanoparticles and the agglomerates resulted in a significant smaller mass median aerodynamic diameter (MMAD) (p?0.05) and higher fine particle dose (FPD) (p?0.01), fine particle fraction (FPF) (p?0.01), and total emitted dose (TED) (p?0.01) than the pure powder.Conclusion: The results suggest that using the combination of edge activators and diluted polycationic polymer solution provides porous voriconazole nanoagglomerates in a respirable range, which is proved successful in enhancing both the deposition and the dissolution of water insoluble-drugs in the lung. 相似文献
13.
Judith Z. Drexler Isa Woo Christopher C. Fuller Glynnis Nakai 《Restoration Ecology》2019,27(5):1117-1127
Few comparisons exist between vertical accretion (VA) and carbon accumulation rates (CARs) in restored versus historic (i.e. reference) marshes. Here, we compare these processes in a formerly diked, sparsely vegetated, restored salt marsh (Six Gill Slough, SG), whose surface is subsided relative to the tidal frame, to an adjacent, relatively pristine, historic salt marsh (Animal Slough, AS). Six sediment cores were collected at both AS and SG approximately 6 years after restoration. Cores were analyzed for bulk density (BD), % loss of ignition, % organic carbon, and 210Pb. We found that sharp changes in BD in surface layers of SG cores were highly reliable markers for the onset of restoration. The mean VA since restoration at SG (0.79 [SD = 0.29] cm/year) was approximately twice that of AS (0.41 [SD = 0.16] cm/year). In comparison, the VA at AS over 50 years was 0.30 (SD = 0.09) cm/year. VA consisted almost entirely of inorganic sediment at SG whereas at AS it was approximately 55%. Mean CARs at SG were somewhat greater than at AS, but the difference was not significant due to high variability (SG: 81–210 g C m?2 year?1; AS: 115–168 g C m?2 year?1). The mean CAR at AS over the past 50 years was 118 (SD = 23) g C m?2 year?1. This study demonstrates that a sparsely vegetated, restored salt marsh can quickly begin to accumulate carbon and that historic and restored marshes can have similar CARs despite highly divergent formation processes. 相似文献
14.
P. Chanphai 《Journal of biomolecular structure & dynamics》2013,31(13):3487-3495
Dietary polyphenols are abundant micronutrients in our diet and paly major role in prevention of degenerative diseases. The binding efficacy of antioxidant polyphenols resveratrol, genistein, and curcumin with PAMAM-G3 and PAMAM-G4 nanoparticles was investigated in aqueous solution at physiological conditions, using multiple spectroscopic methods, TEM images, and docking studies. The polyphenol bindings are via hydrophilic, hydrophobic, and H-bonding contacts with resveratrol forming more stable conjugates. As PAMAM size increased the loading efficacy and the stability of polyphenol-polymer conjugates were increased. Polyphenol binding induced major alterations of dendrimer morphology. PAMAM nanoparticles are capable of delivery of polyphenols in vitro. 相似文献
15.
Brain capillary endothelial cells (BCECs) have been considered as one of the primary targets for cerebral gene therapy. However,
the cells, well-known for their poor function of endocytosis, are difficult to be transfected by general non-viral vectors.
The aim of this study was to enhance the efficiency of transfection and expression in BCECs of DNA/polymer nanoparticles with
the modification of membrane-penetrating peptide, Antennapedia peptide (Antp) polyethylenimine (PEI) and polyamidoamine (PAMAM)
were chosen to prepare Antp-modified DNA-loaded nanoparticles with a complex coacervation technique. After a 20-min transfection,
the efficiency, in terms of transfection and expression, of DNA/PEI NP or DNA/PAMAM NP was enhanced significantly with the
modification of Antp. After a 3-h transfection of DNA/Antp/PEI NP, there was no difference in cellular uptake but an enhancement
in gene expression, compared to DNA/PEI NP alone. However, both the transfection and expression efficiency of DNA/PAMAM NP
were enhanced using Antp. These observations suggest that Antp can increase the membrane-penetrating ability of DNA-loaded
nanoparticles, which can be employed as novel non-viral gene vectors. 相似文献
16.
Chin-Man Wang Huei-Huang Ho Su-Wei Chang Yeong-Jian Jan Wu Jing-Chi Lin Pi-Yueh Chang Jianming Wu Ji-Yih Chen 《Arthritis research & therapy》2012,14(3):R125
IntroductionAnkylosing spondylitis (AS) is a familial, heritable disease specified by syndesmophyte formation leading to an ankylosed spine. Endoplasmic reticulum aminopeptidase 1 (ERAP1) genetic variations have been widely proved to be associated with AS in several ethnic populations. The aim of this study was to investigate whether ERAP1 single nucleotide polymorphisms (SNPs) are associated with AS susceptibility and disease severity in Taiwanese.MethodsFour ERAP1 SNPs (rs27037, rs27980, rs27044 and rs30187) were genotyped in 797 Taiwanese AS patients and 1,150 healthy controls. Distributions of genotype and alleles were compared between AS patients and healthy controls, and among AS patients stratified by clinical parameters.ResultsThe SNP rs27037T allele appeared to be a risk factor for AS susceptibility (P = 5.5 × 10-5, OR 1.30, 95% CI: 1.15 to 1.48; GT+TT vs. GG P = 9.3 × 10-5, OR 1.49, 95% CI: 1.22 to 1.82). In addition, the coding SNP (cSNP) rs27044G allele (P = 1.5 × 10-4, OR 1.28, 95% CI: 1.13 to 1.46; CG+GG vs. CC, P = 1.7 × 10-3, OR 1.44, 95% CI: 1.15 to 1.81) and the cSNP rs30187T allele (P = 1.7 × 10-3, OR 1.23, 95% CI: 1.08 to 1.40; CT+TT vs. CC P = 6.1 × 10-3, OR 1.38, 95% CI: 1.10 to 1.74) were predisposing factors for AS. Notably, the rs27044G allele carriers (CG+GG vs. CC, P = 0.015, OR 1.59, 95% CI: 1.33 to 2.30) and rs30187T allele carriers (CT+TT vs. CC, P = 0.011, OR 1.63, 95% CI: 1.12 to 2.38) were susceptible to syndesmophyte formation in AS patients. Furthermore, two cSNPs (rs27044 and rs30187) strongly associated with HLA-B27 positivity in AS patients. Finally, the ERAP1 SNP haplotype TCG (rs27037T/rs27980C/rs27044G) is a major risk factor for AS (adjusted P <0.00001, OR 1.38, 95% CI: 1.12 to 1.58) in Taiwanese.ConclusionsThis study provides the first evidence of ERAP1 SNPs involving syndesmophyte formation. The interactions between ERAP1 SNPs and HLA-B27 play critical roles in pMHC I pathway processing contributing to the pathogenesis of AS in multiple populations. 相似文献
17.
Challenging of AS160/TBC1D4 Alters Intracellular Lipid milieu in L6 Myotubes Incubated With Palmitate
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Agnieszka Mikłosz Bartłomiej Łukaszuk Małgorzata Żendzian‐Piotrowska Justyna Brańska‐Januszewska Halina Ostrowska Adrian Chabowski 《Journal of cellular physiology》2017,232(9):2373-2386
18.
目的:探讨免疫相关GTP酶1(Irgm 1)对小鼠血管动脉粥样硬化(AS)斑块形成的影响。方法:高脂饲料喂养野生型(WT)、ApoE~(-/-)Irgm 1~(+/+)和ApoE~(-/-)Irgm1~(+/-)小鼠3个月,建立AS模型;取小鼠主动脉弓,免疫荧光染色方法观察WT和ApoE~(-/-)Irgm 1~(+/+)小鼠血管AS斑块中Irgm 1的表达情况及部位;Western blot方法检测WT和ApoE~(-/-)Irgm 1~(+/+)小鼠血管AS斑块中Irgm 1蛋白表达情况;Q-PCR方法检测WT和ApoE~(-/-)Irgm 1~(+/+)小鼠血管AS斑块中Irgm 1 m RNA表达情况;油红O染色观察ApoE~(-/-)Irgm1~(+/+)和ApoE~(-/-)Irgm1~(+/-)小鼠血管AS斑块形成情况;结果:与WT组相比,ApoE~(-/-)Irgm 1~(+/+)组小鼠主动脉弓AS斑块中Irgm 1+细胞明显增多,Irgm 1+细胞主要位于血管AS斑块的表面;与WT组相比,ApoE~(-/-)Irgm 1~(+/+)组小鼠血管AS斑块中Irgm 1蛋白表达显著增多(P0.001),Irgm 1 m RNA表达显著增多(P0.01);与ApoE~(-/-)Irgm1~(+/-)组相比,ApoE~(-/-)Irgm1~(+/+)组小鼠主动脉弓AS斑块面积显著增大(P0.01);结论:Irgm 1能够促进血管AS斑块的形成。 相似文献
19.
20.
Tie-juan Shao Zhi-xing He Zhi-jun Xie Hai-chang Li Mei-jiao Wang Cheng-ping Wen 《Metabolomics : Official journal of the Metabolomic Society》2016,12(4):70