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Johnson SL, Tsou WL, Prifti MV, Harris AL, Todi SV. A survey of protein interactions and posttranslational modifications that influence the polyglutamine diseases. Front Mol Neurosci 2022; 15:974167. [PMID: 36187346 PMCID: PMC9515312 DOI: 10.3389/fnmol.2022.974167] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/27/2022] [Indexed: 01/20/2023] Open
Abstract
The presence and aggregation of misfolded proteins has deleterious effects in the nervous system. Among the various diseases caused by misfolded proteins is the family of the polyglutamine (polyQ) disorders. This family comprises nine members, all stemming from the same mutation—the abnormal elongation of a polyQ repeat in nine different proteins—which causes protein misfolding and aggregation, cellular dysfunction and disease. While it is the same type of mutation that causes them, each disease is distinct: it is influenced by regions and domains that surround the polyQ repeat; by proteins with which they interact; and by posttranslational modifications they receive. Here, we overview the role of non-polyQ regions that control the pathogenicity of the expanded polyQ repeat. We begin by introducing each polyQ disease, the genes affected, and the symptoms experienced by patients. Subsequently, we provide a survey of protein-protein interactions and posttranslational modifications that regulate polyQ toxicity. We conclude by discussing shared processes and pathways that bring some of the polyQ diseases together and may serve as common therapeutic entry points for this family of incurable disorders.
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Affiliation(s)
- Sean L. Johnson
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Wei-Ling Tsou
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Matthew V. Prifti
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
| | - Autumn L. Harris
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
- Maximizing Access to Research Careers (MARC) Program, Wayne State University, Detroit, MI, United States
| | - Sokol V. Todi
- Department of Pharmacology, Wayne State University, Detroit, MI, United States
- Maximizing Access to Research Careers (MARC) Program, Wayne State University, Detroit, MI, United States
- Department of Neurology, Wayne State University, Detroit, MI, United States
- *Correspondence: Sokol V. Todi,
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2
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Agarwal V, Gupta V, Bhardwaj VK, Singh K, Khullar P, Bakshi MS. Hemolytic Response of Iron Oxide Magnetic Nanoparticles at the Interface and in Bulk: Extraction of Blood Cells by Magnetic Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2022; 14:6428-6441. [PMID: 35090343 DOI: 10.1021/acsami.1c23496] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface-active and water-soluble magnetic nanoparticles (NPs) were synthesized in the presence of a series of amphiphilic molecules of different functional groups to determine the hemolytic response and their ability to extract blood cells across the interface and aqueous bulk while maintaining minimum hemolysis. Amphiphilic molecules such as Gemini surfactants of strong hydrophobicity and low hydrophilic-lipophilic balance produced surface-active magnetic NPs, which were highly cytotoxic even when placed at the blood suspension (aqueous)-air interface. A similar behavior was shown by water-soluble magnetic NPs produced using monomeric ionic and nonionic surfactants and different amino acids. The NPs produced using mild biological surfactants and mono- and oligosaccharides of the same functional group proved to be excellent blood cell extractors with minimum hemolysis. α/β-cyclodextrin and dextrose-stabilized magnetic NPs induced negligible hemolysis and extracted more than 50% of blood cells. The results showed that nontoxic magnetic NPs are excellent blood cell extractors from the blood suspension when tagged with amphiphilic molecules possessing good biocompatibility with cell membranes without inducing hemolysis. The work highlights the biological applicability of nontoxic magnetic NPs at biointerfaces and in blood suspensions.
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Affiliation(s)
- Vandana Agarwal
- Department of Chemistry, Dr. B.R. Ambedkar National Institute of Technology, Jalandhar 144011, Punjab, India
- Department of Chemistry, B.B.K. D.A.V. College for Women, Amritsar 143005, Punjab, India
| | - Vikas Gupta
- Department of Biotechnology, DAV College, Amritsar 143001, Punjab, India
| | - Vimal Kumar Bhardwaj
- Department of Chemistry, Dr. B.R. Ambedkar National Institute of Technology, Jalandhar 144011, Punjab, India
| | - Kultar Singh
- Department of Chemistry, Khalsa College, G. T. Road, Amritsar 143002, Punjab, India
| | - Poonam Khullar
- Department of Chemistry, B.B.K. D.A.V. College for Women, Amritsar 143005, Punjab, India
| | - Mandeep Singh Bakshi
- Department of Chemistry, Natural and Applied Sciences, University of Wisconsin─Green Bay, 2420 Nicolet Drive, Green Bay 54311 7001, Wisconsin, United States
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3
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Prokai-Tatrai K, De La Cruz DL, Nguyen V, Ross BP, Toth I, Prokai L. Brain Delivery of Thyrotropin-Releasing Hormone via a Novel Prodrug Approach. Pharmaceutics 2019; 11:E349. [PMID: 31323784 PMCID: PMC6680701 DOI: 10.3390/pharmaceutics11070349] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/14/2019] [Accepted: 07/16/2019] [Indexed: 12/28/2022] Open
Abstract
Using thyrotropin-releasing hormone (TRH) as a model, we explored whether synergistic combination of lipoamino acid(s) and a linker cleaved by prolyl oligopeptidase (POP) can be used as a promoiety for prodrug design for the preferential brain delivery of the peptide. A representative prodrug based on this design principle was synthesized, and its membrane affinity and in vitro metabolic stability, with or without the presence of a POP inhibitor, were studied. The in vivo formation of TRH from the prodrug construct was probed by utilizing the antidepressant effect of the peptide, as well as its ability to increase acetylcholine (ACh) synthesis and release. We found that the prototype prodrug showed excellent membrane affinity and greatly increased metabolic stability in mouse blood and brain homogenate compared to the parent peptide, yet a POP inhibitor completely prevented prodrug metabolism in brain homogenate. In vivo, administration of the prodrug triggered antidepressant-like effect, and microdialysis sampling showed greatly increased ACh release that was also antagonized upon a POP inhibitor treatment. Altogether, the obtained promising exploratory data warrant further investigations on the utility of the prodrug approach introduced here for brain-enhanced delivery of small peptides with neurotherapeutic potential.
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Affiliation(s)
- Katalin Prokai-Tatrai
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
| | - Daniel L De La Cruz
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Vien Nguyen
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Benjamin P Ross
- School of Pharmacy, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Istvan Toth
- School of Chemistry & Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Laszlo Prokai
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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4
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Zhang P, Zhang L, Qin Z, Hua S, Guo Z, Chu C, Lin H, Zhang Y, Li W, Zhang X, Chen X, Liu G. Genetically Engineered Liposome-like Nanovesicles as Active Targeted Transport Platform. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1705350. [PMID: 29280210 DOI: 10.1002/adma.201705350] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Revised: 11/15/2017] [Indexed: 05/26/2023]
Abstract
Ligand-targeted delivery of drug molecules to various types of tumor cells remains a major challenge in precision medicine. Inspired by the secretion process and natural cargo delivery functions of natural exosomes, biomimetic synthetic strategies are exploited to prepare biofunctionalized liposome-like nanovesicles (BLNs) that can artificially display a wide variety of targeting protein/peptide ligands and directly encapsulate medical agents for enhanced drug delivery. Here, as a proof of concept, genetically engineered BLNs, which display human epidermal growth factor (hEGF) or anti-HER2 Affibody as targeting moieties, are developed to, respectively, target two types of tumor cells. Notably, in comparison to synthetic liposomes covalently coupled with hEGF, it is demonstrated in this work that biosynthetically displayed hEGF ligands on BLNs possess higher biological activities and targeting capabilities. Additionally, treatments with doxorubicin-loaded BLNs displaying Affibody ligands exhibit much better antitumor therapeutic outcomes than clinically approved liposomal doxorubicin (Doxil) in HER2-overexpressing BT474 tumor xenograft models. These data suggest that BLN is suitable as a potent surrogate for conventional proteoliposomes or immunoliposomes as a result of excellent targeting capacities and facile production of BLNs.
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Affiliation(s)
- Pengfei Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Long Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
- Department of Hepatobiliary Pancreas and Vessel Surgery, Chenggong Hospital of Xiamen University, Xiamen, 361005, China
| | - Zainen Qin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
- Collaborative Innovation Center of Guangxi Biological Medicine and the, Medical and Scientific Research Center, Guangxi Medical University, Nanning, 530021, China
| | - Suhang Hua
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Zhide Guo
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Chengchao Chu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Huirong Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Yang Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Wengang Li
- Department of Hepatobiliary Pancreas and Vessel Surgery, Chenggong Hospital of Xiamen University, Xiamen, 361005, China
| | - Xianzhong Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
| | - Xiaoyuan Chen
- Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Gang Liu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, 361102, China
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Biology, School of Life Sciences, Xiamen University, Xiamen, 361102, China
- The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
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5
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Du X, Gomez CM. Spinocerebellar [corrected] Ataxia Type 6: Molecular Mechanisms and Calcium Channel Genetics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1049:147-173. [PMID: 29427102 DOI: 10.1007/978-3-319-71779-1_7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Spinocerebellar ataxia (SCA) type 6 is an autosomal dominant disease affecting cerebellar degeneration. Clinically, it is characterized by pure cerebellar dysfunction, slowly progressive unsteadiness of gait and stance, slurred speech, and abnormal eye movements with late onset. Pathological findings of SCA6 include a diffuse loss of Purkinje cells, predominantly in the cerebellar vermis. Genetically, SCA6 is caused by expansion of a trinucleotide CAG repeat in the last exon of longest isoform CACNA1A gene on chromosome 19p13.1-p13.2. Normal alleles have 4-18 repeats, while alleles causing disease contain 19-33 repeats. Due to presence of a novel internal ribosomal entry site (IRES) with the mRNA, CACNA1A encodes two structurally unrelated proteins with distinct functions within an overlapping open reading frame (ORF) of the same mRNA: (1) α1A subunit of P/Q-type voltage gated calcium channel; (2) α1ACT, a newly recognized transcription factor, with polyglutamine repeat at C-terminal end. Understanding the function of α1ACT in physiological and pathological conditions may elucidate the pathogenesis of SCA6. More importantly, the IRES, as the translational control element of α1ACT, provides a potential therapeutic target for the treatment of SCA6.
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Affiliation(s)
- Xiaofei Du
- Department of Neurology, The University of Chicago, Chicago, 60637, IL, USA
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6
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Kumar D, Rub MA. Effect of Sodium Taurocholate on Aggregation Behavior of Amphiphilic Drug Solution. TENSIDE SURFACT DET 2015. [DOI: 10.3139/113.110398] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AbstractThe aggregation behavior of promazine hydrochloride (PMZ) and bile salt (sodium taurocholate (NaTC)) mixtures at various compositions and temperature in pure and mixed states were studied using conductometry technique in aqueous solutions. The values of experimental and ideal critical micelle concentration (cmc and cmcid) propose attractive interactions in PMZ-NaTC mixtures. By applying the regular solution theory (RST) various physicochemical parameter such as micellar mole fraction in the mixed (X1) and ideal (X1id) state, interaction parameters (β), thermodynamic parameters of micellization as well as other related parameters have been evaluated and discussed in detail. The results show that the synergistic effect between drug and bile salt plays a crucial role in the redtdprefuction of the overall cmc value in aqueous solution at various composition of NaTC. The thermodynamic parameters recommend the discharge of water from the hydrophobic part of the PMZ at higher temperatures.
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Affiliation(s)
- Dileep Kumar
- 1Faculty of Science, Universiti Tunku Abdul Rahman, 31900 Kampar, Perak, Malaysia
| | - Malik Abdul Rub
- 2Chemistry Department, King Abdulaziz University, Jeddah-21589, Saudi Arabia
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7
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Abstract
It is a critically important challenge to rapidly design effective vaccines to reduce the morbidity and mortality of unexpected pandemics. Inspired from the way that most enveloped viruses hijack a host cell membrane and subsequently release by a budding process that requires cell membrane scission, we genetically engineered viral antigen to harbor into cell membrane, then form uniform spherical virus-mimetic nanovesicles (VMVs) that resemble natural virus in size, shape, and specific immunogenicity with the help of surfactants. Incubation of major cell membrane vesicles with surfactants generates a large amount of nano-sized uniform VMVs displaying the native conformational epitopes. With the diverse display of epitopes and viral envelope glycoproteins that can be functionally anchored onto VMVs, we demonstrate VMVs to be straightforward, robust and tunable nanobiotechnology platforms for fabricating antigen delivery systems against a wide range of enveloped viruses.
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8
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Simerska P, Ziora ZM, Fagan V, Goodwin D, Edrous F, Toth I. Design, synthesis and characterisation of mannosylated ovalbumin lipid core peptide self-adjuvanting vaccine delivery system. Drug Deliv Transl Res 2015; 4:246-55. [PMID: 25786879 DOI: 10.1007/s13346-013-0173-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Peptide-based vaccine delivery can be hampered by rapid peptidase activity and poor inherent immunogenicity. The self-adjuvanting lipid core peptide system (LCP) has been shown to confer improved stability and immunogenicity on peptide epitopes of group A Streptococcus, Chlamydia, hookworm, and malaria pathogens. However, various diseases, including cancer, still require targeted delivery of their vaccine candidates. For this reason, we have selected two model peptides (ovalbumin CD4(+) and/or CD8(+) T cell epitopes), and incorporated two or four copies of either epitope into our LCP vaccine. Optimised glycosylation of ovalbumin peptides yielded 46 % when microwave-assisted double coupling with 2 eq of carbohydrate derivative, activated by N,N-diisopropylethylamine and (O-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, was performed. All ovalbumin peptides were successfully synthesised and purified in 11-55 % yields by Fmoc- or Boc-chemistry using solid-phase peptide synthesis. The mannosylated ovalbumin peptides were nontoxic to human erythrocytes in haemolytic assay (<2 % haemolysis) and showed increased (up to 20-fold) stability in plasma.
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Affiliation(s)
- Pavla Simerska
- School of Chemistry and Molecular Biosciences, The University of Queensland, Cooper Road, St Lucia, QLD, 4072, Australia,
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9
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Holt BD, Dahl KN, Islam MF. Differential sub-cellular processing of single-wall carbon nanotubes via interfacial modifications. J Mater Chem B 2015; 3:6274-6284. [DOI: 10.1039/c5tb00705d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Real-space and fluorescence lifetime imaging reveal that non-covalently attached dispersing agents influence sub-cellular trafficking and localization of carbon nanotubes.
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Affiliation(s)
- Brian D. Holt
- Department of Materials Science and Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
| | - Kris Noel Dahl
- Department of Biomedical Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
- Department of Chemical Engineering
| | - Mohammad F. Islam
- Department of Materials Science and Engineering
- Carnegie Mellon University
- Pittsburgh
- USA
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10
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Sar P, Ghosh A, Ghosh D, Saha B. Micellar catalysis of quinquivalent vanadium oxidation of methanol to formaldehyde in aqueous medium. RESEARCH ON CHEMICAL INTERMEDIATES 2014. [DOI: 10.1007/s11164-014-1682-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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11
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Bai G, Wang Y, Nichifor M, Bastos M. Critical role of the degree of substitution in the interaction of biocompatible cholic acid-modified dextrans with phosphatidylcholine liposomes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:13258-13268. [PMID: 24079348 DOI: 10.1021/la402754y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The interaction between biocompatible cholic acid-modified dextrans with different pendent cholic acid groups' content and phosphatidylcholine liposomes was studied by a variety of techniques including isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), turbidity measurements, microscopy imaging (transmission electron microscopy (TEM), and cryo-scanning electron microscopy (cryo-SEM)). The variation of the interaction enthalpy with polymer concentration, as obtained by ITC, highlighted the formation of different aggregates. Complete phase modification, from vesicles covered with a few polymer chains to vesicle disintegration, was observed by turbidity measurements. DSC showed the effect of polymer addition to the liposome gel to liquid-crystalline phase transition, and microscopy images gave information about the size and morphology of the aggregates. The composition, structure, and morphology of polymer/liposome aggregates were found to be strongly influenced by the cholic acid content in the polymer (degree of substitution, DS). Along with a rather monotonous change in the polymer/liposome system's properties with increasing DS, a discontinuity in behavior could also be observed at DS = 4 mol %. For DS ≤ 4 mol %, the polymer/liposome interaction takes place mainly between individual components, and liposome disintegration occurs in a narrow concentration range, whereas for DS > 4 mol % extended physical networks are formed, which last over a wide concentration range. A mechanism of interaction, as a function of DS, is proposed and discussed in detail.
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Affiliation(s)
- Guangyue Bai
- School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University , Xinxiang, Henan 453007, China
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12
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Collapsing the Proton Motive Force to Identify Synergistic Combinations against Staphylococcus aureus. ACTA ACUST UNITED AC 2013; 20:1168-78. [DOI: 10.1016/j.chembiol.2013.07.006] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/11/2013] [Accepted: 07/16/2013] [Indexed: 12/19/2022]
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13
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Holt BD, McCorry MC, Boyer PD, Dahl KN, Islam MF. Not all protein-mediated single-wall carbon nanotube dispersions are equally bioactive. NANOSCALE 2012; 4:7425-7434. [PMID: 23086474 DOI: 10.1039/c2nr31928d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Single-wall carbon nanotubes (SWCNTs) have been dispersed with proteins to increase biocompatibility and specificity, but examinations of dispersion parameters on functional cellular uptake are required for utilization of SWCNTs in biological applications. Here we correlate conditions of SWCNT dispersion with various proteins to uptake these SWCNTs in NIH-3T3 fibroblasts and J774A.1 macrophage-like cells. We varied protein types (bovine serum albumin - BSA, lysozyme - LSZ, and γ-globulins - γG), protein : SWCNT ratio and sonication time. Each protein created stable, high yield (~25%) dispersions in water while preserving intrinsic SWCNT fluorescence, but SWCNT-LSZ flocculated in media and SWCNT-γG formed clusters in both water and media, drastically altering cellular internalization. Dispersion quality and yield improved with increased protein : SWCNT - without substantial effects from depletion attraction, even at 100 : 1 protein : SWCNT - and slightly increased internalized SWCNTs for both NIH-3T3 and J774A.1 cells. Longer sonication time (12 versus 2 h) improved the dispersion yield and quality but caused minor damage to SWCNTs and altered protein structure. Cell association of SWCNT-BSA was homogenous and unaltered by sonication time. Bulk assay showed that cell association of SWCNT-LSZ and SWCNT-γG was altered with 12 versus 2 h sonication, but imaging of individual cells showed that these differences are likely from precipitation of clusters of SWCNT-LSZ and SWCNT-γG in media onto cells. Hence, the quality of SWCNT-protein dispersions in water does not necessarily correlate with bulk cellular uptake, and quantification at the level of individual cells is required to determine delivery efficacy.
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Affiliation(s)
- Brian D Holt
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
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14
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Falkinham JO, Macri RV, Maisuria BB, Actis ML, Sugandhi EW, Williams AA, Snyder AV, Jackson FR, Poppe MA, Chen L, Ganesh K, Gandour RD. Antibacterial activities of dendritic amphiphiles against nontuberculous mycobacteria. Tuberculosis (Edinb) 2011; 92:173-81. [PMID: 22209468 DOI: 10.1016/j.tube.2011.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 11/30/2011] [Accepted: 12/04/2011] [Indexed: 10/14/2022]
Abstract
The anti-mycobacterial activities of nine series of dicarboxyl and tricarboxyl dendritic amphiphiles with one alkyl, two alkyl, and cholestanyl tails against Mycobacterium abscessus, Mycobacterium avium, Mycobacterium chelonae, Mycobacterium marinum and Mycobacterium smegmatis have been measured. The dendritic amphiphiles overcame the limited aqueous solubility of natural long-chain fatty acids, alcohols, and amines to enable profiling the susceptibilities of the different mycobacterial species to the physicochemical properties of these amphiphiles. Several dendritic amphiphiles showed strong anti-mycobacterial activity with high critical micelle concentrations and low hemolytic activities thereby offering platforms for the development of antibiotics of higher activity against nontuberculous mycobacteria.
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Affiliation(s)
- Joseph O Falkinham
- Department of Biological Science (0406), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
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15
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Ledbetter MR, Gutsell S, Hodges G, Madden JC, O'Connor S, Cronin MTD. Database of published retention factors for immobilized artificial membrane HPLC and an assessment of the effect of experimental variability. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:2701-8. [PMID: 21919042 DOI: 10.1002/etc.677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 07/22/2011] [Accepted: 08/16/2011] [Indexed: 05/13/2023]
Abstract
A database was collated of published experimental logarithmic values for the relative retention factors (log k(IAM)) measured using an immobilized artificial membrane column and high-performance liquid chromatography (IAM HPLC). Log k(IAM) is an alternative measure of hydrophobicity to the octanol/water partition coefficient (log K(OW)). While there are several accepted methods to measure log K(OW), no standardized method exists to determine log k(IAM). The database of collated log k(IAM) values includes 13 key experimental parameters and contains 1,686 values for 555 compounds, which are predominantly polar organic compounds and include drug molecules and surfactants. These compounds are acidic, basic, and neutral and both ionized and un-ionized under the conditions of analysis. The data compiled demonstrated experimental variability for each experimental parameter considered, including column stationary phase, pH, temperature, and mobile phase. Reducing the experimental variability allowed for greater consistency in the datasets.
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Affiliation(s)
- M R Ledbetter
- School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool, UK
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16
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Yang L, Tucker IG, Østergaard J. Effects of bile salts on propranolol distribution into liposomes studied by capillary electrophoresis. J Pharm Biomed Anal 2011; 56:553-9. [PMID: 21784594 DOI: 10.1016/j.jpba.2011.06.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/31/2011] [Accepted: 06/24/2011] [Indexed: 11/19/2022]
Abstract
The objective of this study was to study the effect of four different bile salts, cholate (C), deoxycholate (DC), taurocholate (TC), monoketocholate (MKC), on the membrane binding of a cationic model drug, propranolol, using capillary electrophoresis. The apparent distribution coefficient of propranolol in a buffer/liposome system, in the absence and presence of various concentrations of the bile salts, was measured using capillary electrophoresis frontal analysis. At bile salt concentrations which did not disrupt the liposomes, the bile salts increased the apparent distribution coefficient of propranolol in a concentration-dependent manner, to various extents (DC>C>TC>MKC). The mechanisms for these increases were inferred from studies of ion pairing between bile salts and propranolol using mobility shift affinity capillary electrophoresis and from zeta potential measurements. The bile salts ion-paired with propranolol to different extents as indicated by the estimated complexation constants (K range: 30-58 M(-1)). This was found to have a minor effect on the membrane distribution of propranolol only. The major effect is proposed to be due to the insertion of bile salt into the liposomal membranes leading to a more negatively charged membrane surface thereby providing stronger electrostatic interactions with the positively charged propranolol.
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Affiliation(s)
- Lin Yang
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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17
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The role of bile salts in digestion. Adv Colloid Interface Sci 2011; 165:36-46. [PMID: 21236400 DOI: 10.1016/j.cis.2010.12.002] [Citation(s) in RCA: 364] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/06/2010] [Accepted: 12/07/2010] [Indexed: 01/13/2023]
Abstract
Bile salts (BS) are bio-surfactants present in the gastrointestinal tract (GIT) that play a crucial role in the digestion and absorption of nutrients. The importance of BS for controlled release and transport of lipid soluble nutrients and drugs has recently stimulated scientific interest in these physiological compounds. BS are so-called facial amphiphiles showing a molecular structure that is very distinct from classical surfactants. This peculiar molecular structure facilitates the formation of dynamic aggregates able to solubilise and transport lipid soluble compounds. The detergent nature of BS has been studied in the literature, mostly concentrating on the self-assembly behaviour of BS in solution but also in relation to protein denaturation and its effect on improving proteolysis. In contrast, the affinity of BS for hydrophobic phases has received less attention and studies dealing directly with the interfacial behaviour of BS are very limited in the literature. This is despite the fact that the interfacial activity of BS plays a vital role in fat digestion since it is closely involved with lypolisis. BS adsorb onto fat droplets and can remove other materials such as proteins, emulsifiers and lipolysis products from the lipid surface. The unusual surface behaviour of BS is directly related to their intriguing molecular structure and further knowledge could provide an improved understanding of lipid digestion. This review aims to combine the new insights gained into the surface properties of BS and their role in digestion. A better understanding of surface activity of BS would allow manipulation of physico-chemical and interfacial properties to modulate lipid digestion, improve bioavailability of lipid soluble nutrients and reduce absorption of saturated fats, cholesterol and trans fats.
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Kabir-ud-Din, Rub MA, Naqvi AZ. Aqueous amphiphilic drug (amitriptyline hydrochloride)–bile salt mixtures at different temperatures. Colloids Surf B Biointerfaces 2011; 84:285-91. [DOI: 10.1016/j.colsurfb.2011.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 01/07/2011] [Accepted: 01/07/2011] [Indexed: 10/18/2022]
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19
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Maisuria BB, Actis ML, Hardrict SN, Falkinham JO, Cole MF, Cihlar RL, Peters SM, Macri RV, Sugandhi EW, Williams AA, Poppe MA, Esker AR, Gandour RD. Comparing micellar, hemolytic, and antibacterial properties of di- and tricarboxyl dendritic amphiphiles. Bioorg Med Chem 2011; 19:2918-26. [DOI: 10.1016/j.bmc.2011.03.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 03/10/2011] [Accepted: 03/17/2011] [Indexed: 10/18/2022]
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Non-esterified fatty acids generate distinct low-molecular weight amyloid-β (Aβ42) oligomers along pathway different from fibril formation. PLoS One 2011; 6:e18759. [PMID: 21526230 PMCID: PMC3079704 DOI: 10.1371/journal.pone.0018759] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 03/09/2011] [Indexed: 12/13/2022] Open
Abstract
Amyloid-β (Aβ) peptide aggregation is known to play a central role in the etiology of Alzheimer’s disease (AD). Among various aggregates, low-molecular weight soluble oligomers of Aβ are increasingly believed to be the primary neurotoxic agents responsible for memory impairment. Anionic interfaces are known to influence the Aβ aggregation process significantly. Here, we report the effects of interfaces formed by medium-chain (C9–C12), saturated non-esterified fatty acids (NEFAs) on Aβ42 aggregation. NEFAs uniquely affected Aβ42 aggregation rates that depended on both the ratio of Aβ:NEFA as well the critical micelle concentration (CMC) of the NEFAs. More importantly, irrespective of the kind of NEFA used, we observed that two distinct oligomers, 12–18 mers and 4–5 mers were formed via different pathway of aggregation under specific experimental conditions: (i) 12–18 mers were generated near the CMC in which NEFAs augment the rate of Aβ42 aggregation towards fibril formation, and, (ii) 4–5 mers were formed above the CMC, where NEFAs inhibit fibril formation. The data indicated that both 12–18 mers and 4–5 mers are formed along an alternate pathway called ‘off-pathway’ that did not result in fibril formation and yet have subtle structural and morphological differences that distinguish their bulk molecular behavior. These observations, (i) reflect the possible mechanism of Aβ aggregation in physiological lipid-rich environments, and (ii) reiterate the fact that all oligomeric forms of Aβ need not be obligatory intermediates of the fibril formation pathway.
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Wong PE, Tetley L, Dufès C, Chooi KW, Bolton K, Schätzlein AG, Uchegbu IF. Polyamine aza-cyclic compounds demonstrate anti-proliferative activity in vitro but fail to control tumour growth in vivo. J Pharm Sci 2011; 99:4642-57. [PMID: 20845462 DOI: 10.1002/jps.22165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cationic polyamines such as the poly(propylenimine) dendrimers (DAB16) are anti-tumour agents (Dufes et al., 2005, Cancer Res 65:8079-8084). Their mechanism of action is poorly understood, but the lack of in vivo toxicity suggests cancer specificity. To explore this polyamine pharmacophore we cross-linked the aza-cyclic compound, hexacyclen, with 1,4-dibromobutane or 1,8-dibromooctane to yield the polyamines [poly(butylhexacyclen)--CL4] or [poly(octylhexacyclen)--CL8] respectively, both free of primary amines. We characterised the compounds and their respective nanoparticles and examined their interaction with the putative targets of the cationic polyamines: the cell membrane and DNA. Like DAB 16, CL4 and CL8 bind plasmid DNA and all three compounds interrupted the cell cycle of A431 epidermoid carcinoma cells in the S-phase. Additionally all three compounds disrupted erythrocyte membranes, with CL8 and DAB 16 being more active, in this respect, than CL4. CL4 (IC(50) =775.1 µg mL(-1)) and CL8 (IC(50) =8.4 µg mL(-1)), in a similar manner to DAB 16, were anti-proliferative against A431 cells; although unlike DAB 16, CL4 and CL8 were not tumouricidal against A431 xenografts in mice, indicating that primary amines may play an important role in the in vivo activity of DAB 16.
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Affiliation(s)
- Pui Ee Wong
- Division of Infection & Immunity, University of Glasgow, Glasgow, UK
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22
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Bergeon JA, Ziora ZM, Abdelrahim AS, Pernevi NU, Moss AR, Toth I. In vitro and In vivo evaluation of positively charged liposaccharide derivatives as oral absorption enhancers for the delivery of anionic drugs. J Pharm Sci 2010; 99:2333-42. [DOI: 10.1002/jps.21999] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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Kovács K, Antal I, Stampf G, Klebovich I, Ludányi K. Composition optimization and stability testing of a parenteral antifungal solution based on a ternary solvent system. AAPS PharmSciTech 2010; 11:285-93. [PMID: 20182828 DOI: 10.1208/s12249-009-9368-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 12/16/2009] [Indexed: 11/30/2022] Open
Abstract
An intravenous solution is a dosage forms intended for administration into the bloodstream. This route is the most rapid and the most bioavailable method of getting drugs into systemic circulation, and therefore it is also the most liable to cause adverse effects. In order to reduce the possibility of side effects and to ensure adequate clinical dosage of the formulation, the primarily formulated composition should be optimized. It is also important that the composition should retain its therapeutic effectiveness and safety throughout the shelf-life of the product. This paper focuses on the optimization and stability testing of a parenteral solution containing miconazole and ketoconazole solubilized with a ternary solvent system as model drugs. Optimization of the solvent system was performed based on assessing the risk/benefit ratio of the composition and its properties upon dilution. Stability tests were conducted based on the EMEA (European Medicines Agency) "guideline on stability testing: stability testing of existing active substances and related finished products". Experiments show that both the amount of co-solvent and surface active agent of the solvent system could substantially be reduced, while still maintaining adequate solubilizing power. It is also shown that the choice of various containers affects the stability of the compositions. It was concluded that by assessing the risk/benefit ratio of solubilizing power versus toxicity, the concentration of excipients could be considerably decreased while still showing a powerful solubilizing effect. It was also shown that a pharmaceutically acceptable shelf-life could be assigned to the composition, indicating good long-term stability.
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Huang Y, Li L, Fang Y. Self-assembled particles of N-phthaloylchitosan-g-polycaprolactone molecular bottle brushes as carriers for controlled release of indometacin. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:557-565. [PMID: 19784761 DOI: 10.1007/s10856-009-3880-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Accepted: 09/17/2009] [Indexed: 05/28/2023]
Abstract
A series of amphiphilic N-phthaloylchitosan-g-polycaprolactone molecular bottle brushes were prepared by "graft onto" method. The narrow distribution of polycaprolactone macromonomers ensures that the molecular bottle brushes can self-assemble into highly monodisperse particles, which have the ability to get a high loading efficiency of the hydrophobic drug, indometacin (INN). Searching for the effective drug loading ratio, three parameters such as polycaprolactone chain length, the grafting content and concentration of the molecular bottle brushes were tested to entrap INN. These encapsulated drug particles show sustained release of the encapsulated INN, of which 91.7% was released in 22 h at 37 degrees C in phosphate buffered saline. The self-assembled particles of the molecular bottle brushes as carriers for INN can effectively prevent the drug from releasing quickly and prolong the release time, which is a promising candidate for potential clinical applications.
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Affiliation(s)
- Youju Huang
- National Synchrotron Radiation Lab and College of Nuclear Science and Technology, University of Science and Technology of China, Hefei, 230026, People's Republic of China
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25
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Abdelrahim AS, Ziora ZM, Bergeon JA, Moss AR, Toth I. Design and synthesis of a series of novel, cationic liposaccharide derivatives as potential penetration enhancers for oral drug delivery. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.08.072] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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26
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Yang L, Zhang H, Mikov M, Tucker IG. Physicochemical and Biological Characterization of Monoketocholic Acid, a Novel Permeability Enhancer. Mol Pharm 2009; 6:448-56. [DOI: 10.1021/mp800143w] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lin Yang
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Hu Zhang
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Momir Mikov
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Ian G. Tucker
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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28
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Ren L, Huang XL, Zhang B, Sun LP, Zhang QQ, Tan MC, Chow GM. Cisplatin-loaded Au–Au2S nanoparticles for potential cancer therapy: Cytotoxicity,in vitro carcinogenicity, and cellular uptake. J Biomed Mater Res A 2008; 85:787-96. [PMID: 17896762 DOI: 10.1002/jbm.a.31608] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cisplatin is one of the most effective cytotoxic agents against cancers. Its usage, however, is limited because of severe resistance and systemic toxicity. A formulation of cisplatin-loaded Au-Au(2)S nanoparticles (NPs) with near-IR (NIR) sensitivity is reported to partly overcome this limitation in this paper. NIR sensitive Au-Au(2)S NPs were successfully synthesized by the reduction of tetrachloroauric acid (HAuCl(4)) using sodium sulfide (Na(2)S), and cisplatin was loaded onto Au-Au(2)S NPs via a MUA (11-mercaptoundecanoic acid) layer. To further investigate the biological safety of cisplatin-loaded Au-Au(2)S NPs, three different cell lines were used to investigate the acute cytotoxicity and the long-term potential carcinogenicity in vitro. Cisplatin-loaded Au-Au(2)S NPs were also tested for limited hemocompatibility in vitro. Our in vitro short and long-term data provided preliminary evidence suggesting that cisplatin-loaded Au-Au(2)S NPs with NIR sensitivity are nontoxic below the maximum recommended dosage.
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Affiliation(s)
- Lei Ren
- Research Center of Biomedical Engineering, Medical College, Xiamen University, Xiamen 361005, People's Republic of China.
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29
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Membranolytic activity of bile salts: influence of biological membrane properties and composition. Molecules 2007; 12:2292-326. [PMID: 17978759 DOI: 10.3390/12102292] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Revised: 10/15/2007] [Accepted: 10/15/2007] [Indexed: 01/15/2023] Open
Abstract
The two main steps of the membranolytic activity of detergents: 1) the partitioning of detergent molecules in the membrane and 2) the solubilisation of the membrane are systematically investigated. The interactions of two bile salt molecules, sodium cholate (NaC) and sodium deoxycholate (NaDC) with biological phospholipid model membranes are considered. The membranolytic activity is analysed as a function of the hydrophobicity of the bile salt, ionic strength, temperature, membrane phase properties, membrane surface charge and composition of the acyl chains of the lipids. The results are derived from calorimetric measurements (ITC, isothermal titration calorimetry). A thermodynamic model is described, taking into consideration electrostatic interactions, which is used for the calculation of the partition coefficient as well as to derive the complete thermodynamic parameters describing the interaction of detergents with biological membranes (change in enthalpy, change in free energy, change in entropy etc). The solubilisation properties are described in a so-called vesicle-to-micelle phase transition diagram. The obtained results are supplemented and confirmed by data obtained from other biophysical techniques (DSC differential scanning calorimetry, DLS dynamic light scattering, SANS small angle neutron scattering).
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30
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Sprunger L, Blake-Taylor BH, Wairegi A, Acree WE, Abraham MH. Characterization of the retention behavior of organic and pharmaceutical drug molecules on an immobilized artificial membrane column with the Abraham model. J Chromatogr A 2007; 1160:235-45. [PMID: 17543312 DOI: 10.1016/j.chroma.2007.05.051] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 05/11/2007] [Accepted: 05/15/2007] [Indexed: 11/29/2022]
Abstract
Data have been compiled from the published literature on the retention factors of 174 organic compounds and drug molecules eluted from a Regis Technologies IAM.PC.DD2 HPLC column using an aqueous mobile phase buffered in the pH range of pH 6.5-7.5. The logarithms of the retention factors are correlated with the Abraham solvation parameter model. The derived correlation contains the five Abraham solute descriptors plus two additional indicator descriptors (I(COOH) and I(amine)) that would be needed whenever carboxylic acid and alkylamine solutes are eluted in ionic form. The derived correlation describes the experimental capacity data of 174 neutral, acidic and basic compounds to within 0.21 log units.
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Affiliation(s)
- Laura Sprunger
- Department of Chemistry, P.O. Box 305070, University of North Texas, Denton, TX 76203-5070, USA
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31
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Wessling ST, Ross BP, Koda Y, Blanchfield JT, Toth I. Caco-2 cell permeability and stability of two d-glucopyranuronamide conjugates of thyrotropin-releasing hormone. Bioorg Med Chem 2007; 15:4946-50. [PMID: 17498958 DOI: 10.1016/j.bmc.2007.04.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/28/2007] [Accepted: 04/25/2007] [Indexed: 10/23/2022]
Abstract
Caco-2 cell permeability and stability assays were used as an in vitro model to study the intestinal epithelial transport and stability of two analogues of thyrotropin-releasing hormone (TRH; Pyr-His-Pro-NH2). Peptide 1 (Pyr-His-Pro-D-glucopyranuronamide) was more permeable across the Caco-2 cell monolayer compared with the permeability of the parent TRH peptide (Papp=5.10+/-1.89x10(-6) cm/s c.f. Papp=0.147+/-0.0474x10(-6) cm/s respectively). The permeability of peptide 1 was improved threefold by attaching a 2-aminooctanoic acid moiety to the N-terminus to form peptide 2 (2-aminooctanoic acid-Gln-His-Pro-D-glucopyranuronamide) (Papp=16.3+/-2.47x10(-6) cm/s). The half-life for both peptide 1 and peptide 2 was approximately 20 min in a homogenate of Caco-2 cells compared with the half-life of TRH which is approximately 3 min. It was concluded that the permeability of peptides 1 and 2 was enhanced because of their increased stability, while the higher permeability of peptide 2 compared with peptide 1 may be attributed to its increased lipophilicity which results in enhanced passive diffusion.
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Affiliation(s)
- Susanne T Wessling
- School of Molecular and Microbial Sciences, The University of Queensland, Brisbane, Qld. 4072, Australia
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32
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Balakrishna R, Wood SJ, Nguyen TB, Miller KA, Suresh Kumar EVK, Datta A, David SA. Structural correlates of antibacterial and membrane-permeabilizing activities in acylpolyamines. Antimicrob Agents Chemother 2006; 50:852-61. [PMID: 16495242 PMCID: PMC1426419 DOI: 10.1128/aac.50.3.852-861.2006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A homologous series of mono- and bis-acyl polyamines with varying acyl chain lengths originally synthesized for the purpose of sequestering lipopolysaccharide were evaluated for antimicrobial activity to test the hypothesis that these bis-cationic amphipathic compounds may also bind to and permeabilize intact gram-negative bacterial membranes. Some compounds were found to possess significant antimicrobial activity, mediated via permeabilization of bacterial membranes. Structure-activity relationship studies revealed a strong dependence of the acyl chain length on antimicrobial potency and permeabilization activity. Homologated spermine, bis-acylated with C8 or C9 chains, was found to profoundly sensitize Escherichia coli to hydrophobic antibiotics such as rifampin. Nonspecific cytotoxicity is a potential drawback of these membranophilic compounds. However, the surface activity of these cationic amphipaths is strongly attenuated under physiological conditions via binding to serum albumin. Significant antibacterial activity is still retained in the presence of physiological concentrations of human serum albumin, suggesting that these compounds may serve as leads in the development of novel adjuncts to conventional antimicrobial chemotherapy.
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Affiliation(s)
- Rajalakshmi Balakrishna
- Department of Medicinal Chemistry, 145E Bldg. B, University of Kansas, Life Sciences Research Laboratories, 1501 Wakarusa Drive, Lawrence, Kansas 66049, USA
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Jin Y, Tong L, Ai P, Li M, Hou X. Self-assembled drug delivery systems. Int J Pharm 2006; 309:199-207. [PMID: 16377106 DOI: 10.1016/j.ijpharm.2005.11.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Revised: 11/08/2005] [Accepted: 11/15/2005] [Indexed: 11/19/2022]
Abstract
Self-assembled drug delivery systems (SADDS) were designed in the paper. They can be prepared from the amphiphilic conjugates of hydrophilic drugs and lipids through self-assembling into small-scale aggregates in aqueous media. The outstanding characteristic of SADDS is that they are nearly wholly composed of amphiphilic prodrugs. The self-assembled nanoparticles (SAN) as one of SADDS had been prepared from the lipid derivative of acyclovir (SGSA) in the previous paper. They were further studied on the properties and the in vitro/in vivo behavior in this paper. The SAN kept the physical state stable upon centrifugation or some additives including some inorganic salts, alkaline solutions, surfactants and liposomes except for HCl solution, CaCl(2) solution and animal plasma. Autoclave and bath heat for sterilization hardly influenced the SAN. However, gamma-irradiation strongly destroyed the structure of SAN and SGSA was degraded. SGSA in SAN showed good stability in weak acidic or neutral buffers although it was very sensitive to alkaline solutions and carboxylester enzymes, the half-lives (t(1/2)) of which in the buffer at pH 7.4, the alkaline solution at pH 12.0, pig liver carboxylester enzyme solution, rabbit plasma, and rabbit liver tissue homogenate were 495, 21, 4.7, 25 and 8.7 h, respectively. Compared with SGSA in a disordered state, the specific bilayer structures of SAN could protect SGSA from hydrolysis through hiding the sensitive ester bonds. The SAN showed hemolytic action because the amphiphilic SGSA could insert into rabbit erythrocyte membranes. Both the high concentration of SGSA in samples and the long incubation time improved hemolysis. No hemolysis was observed if the additional volume of the SAN was less than 10% of rabbit whole blood in spite of the high concentration of SGSA. Plasma proteins could interfere the interaction between the SAN and erythrocytes by binding the SAN. The in vitro antiviral activity of acyclovir SAN was limited possibly because of the weak hydrolysis of SGSA in Vero cells, and the SAN showed a little cell toxicity possible due to the amphiphilicity of SGSA. A macrophage cell line of QXMSC1 cells showed uptake of the SAN but not significantly. The SAN were rapidly removed from blood circulation after bolus iv administration to rabbits with the very short distribution t(1/2) (1.5 min) and the elimination t(1/2) (47 min). The SAN were mainly distributed in liver, spleen and lung after iv administration, and SGSA was eliminated slowly in these tissues (t(1/2), about 7 h). It would appear that the nanosized SAN were trapped by the mononuclear phagocyte system. SADDS including SAN combine prodrugs, molecular self-assembly with nanotechnology, and hopefully become novel drug delivery approaches.
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Affiliation(s)
- Yiguang Jin
- Department of Pharmaceutical Chemistry, Beijing Institute of Radiation Medicine, Beijing 100850, PR China.
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Hayes PY, Ross BP, Thomas BG, Toth I. Polycationic lipophilic-core dendrons as penetration enhancers for the oral administration of low molecular weight heparin. Bioorg Med Chem 2006; 14:143-52. [PMID: 16169233 DOI: 10.1016/j.bmc.2005.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Revised: 08/01/2005] [Accepted: 08/01/2005] [Indexed: 10/25/2022]
Abstract
Two polycationic lipophilic-core carbohydrate-based dendrons 2a-b and five polycationic lipophilic-core peptide dendrons 3-6, containing four arginine or lysine terminal residues, were synthesized and then tested in rats as penetration enhancers for the oral delivery of low molecular weight heparin. Better results were obtained with dendrons containing terminal lysine residues than terminal arginine. A significant anti-factor Xa activity was obtained when low molecular weight heparin was coadministered with dendron 5.
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Affiliation(s)
- Patricia Y Hayes
- Discipline of Chemistry, School of Molecular and Microbial Sciences, and School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072, Australia
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Miller KA, Suresh Kumar EVK, Wood SJ, Cromer JR, Datta A, David SA. Lipopolysaccharide sequestrants: structural correlates of activity and toxicity in novel acylhomospermines. J Med Chem 2005; 48:2589-99. [PMID: 15801849 PMCID: PMC1360202 DOI: 10.1021/jm049449j] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipopolysaccharides (LPS), otherwise termed "endotoxins", are outer membrane constituents of Gram-negative bacteria. Lipopolysaccharides play a key role in the pathogenesis of "septic shock", a major cause of mortality in the critically ill patient. Therapeutic options aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide do not exist at the present time. We have defined the pharmacophore necessary for small molecules to specifically bind and neutralize LPS and, using animal models of sepsis, have shown that the sequestration of circulatory LPS by small molecules is a therapeutically viable strategy. In this paper, the interactions of a series of acylated homologated spermine compounds with LPS have been characterized. The optimal acyl chain length for effective sequestration of LPS was identified to be C(16) for the monoacyl compounds. The most promising of these compounds, 4e, binds LPS with an ED(50) of 1.37 muM. Nitric oxide production in murine J774A.1 cells, as well as TNF-alpha in human blood, is inhibited in a dose-dependent manner by 4e at concentrations orders of magnitude lower than toxic doses. Administration of 4e to d-galactosamine-sensitized mice challenged with supralethal doses of LPS provided significant protection against lethality. Potent antiendotoxic activity, low toxicity, and ease of synthesis render this class of compounds candidate endotoxin-sequestering agents of potential significant therapeutic value.
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Affiliation(s)
- Kelly A Miller
- Department of Medicinal Chemistry, Life Sciences Research Laboratories, 1501 Wakarusa Drive, University of Kansas, Lawrence, Kansas 66049, USA.
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