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1.
Biomacromolecules ; 17(11): 3706-3713, 2016 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-27741396

RESUMO

Dying cells release nucleic acids (NA) and NA-containing complexes that activate inflammatory pathways of immune cells. Sustained activation of these pathways contributes to chronic inflammation frequently encountered in autoimmune and inflammatory diseases. In this study, grafting of cationic polymers onto a nanofibrous mesh enabled local scavenging of negatively charged pro-inflammatory molecules in the extracellular space. Nucleic acid scavenging nanofibers (NASFs) formed from poly(styrene-alt-maleic anhydride) conjugated with 1.8 kDa bPEI resulted in nanofibers of diameters 486 ± 9 nm. NASFs inhibited the NF-κB response stimulated by the negatively charged agonists, CpG and poly(I:C), in Ramos-blue cells but not Pam3CSK4, a nonanionic agonist. Moreover, NASFs significantly impeded NF-κB activation in cells stimulated with damage-associated molecular pattern molecules (DAMPs) released from doxorubicin killed cancer cells. In vivo application of NASFs to open wounds demonstrated nucleic acid scavenging in wounds of diabetic mice infected with Pseudomonas aeruginosa, suggesting the in vivo efficacy of NASFs. This simple technique of generating NASF results in effective localized anti-inflammation in vitro and local nucleic acid scavenging in vivo.


Assuntos
Inflamação/tratamento farmacológico , Maleatos/química , Nanofibras/química , Poliestirenos/química , Cicatrização/efeitos dos fármacos , Animais , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Humanos , Inflamação/microbiologia , Inflamação/patologia , Maleatos/administração & dosagem , Camundongos , Camundongos Endogâmicos NOD , Nanofibras/administração & dosagem , Ácidos Nucleicos/química , Poliaminas/administração & dosagem , Poliaminas/química , Polieletrólitos , Poliestirenos/administração & dosagem , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade
2.
Chem Soc Rev ; 39(10): 3664-74, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20730154

RESUMO

This tutorial review provides a summary of anion-mediated folding of linear and cyclic oligomers as well as anion-responsive behaviours of related polymeric architectures. Anions have emerged as a significant focus of the supramolecular community and here we review their impact on directing the secondary structures of synthetic oligomers and polymers while modulating physical properties e.g. molecular recognition. Oligomers and polymers responsive to anionic guests are typically constructed with hydrogen bond donors complementary to the target anions. Anion binding within the cavities leads to folding and helical wrapping of linear and cyclic oligomers as well as control over macromolecular properties of polymers. This review covers the impact of anion binding on guiding the secondary structures of single-stranded folded oligomers (foldamers) and cyclic oligomers (macrocycles), and on modulating the physical properties of select polymer architectures.


Assuntos
Ânions/química , Polímeros/química , Indóis/química , Pirróis/química , Triazóis/química , Ureia/química
3.
Chem Commun (Camb) ; 46(5): 764-6, 2010 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-20087513

RESUMO

Hydrogen bonding to anions drives the helical folding of an indolocarbazole oligomer, thus resulting in an internal cavity with six NHs and two OHs for binding sulfate with high selectivity.


Assuntos
Carbazóis/química , Sulfatos/química , Sítios de Ligação , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Soluções
4.
J Org Chem ; 74(23): 8924-34, 2009 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-19886635

RESUMO

The flexible, electropositive cavity of linear 1,4-diaryl-1,2,3-triazole oligomers provides a suitable host for complexation of various anions. The binding affinities for various combinations of oligomer and anion were determined by (1)H NMR titrations. Effective ionic radius is found to be a primary determinant of the relative binding interactions of various guests, with small but measurable deviations in the case of nonspherical anions. Solvent effects are significant, and the strength of the binding interaction is found to depend directly on the donor ability of the solvent. A picture emerges in which anion binding can be effectively interpreted in terms of a competition between two solvation spheres: one provided by the solvent and a second dominated by a folded cavity lined with electropositive 1,2,3-triazole CH protons. Implications for rigid macrocycles and other multivalent hosts are discussed.


Assuntos
Ânions/química , Polímeros/química , Triazóis/química , Sítios de Ligação , Compostos Macrocíclicos , Espectroscopia de Ressonância Magnética , Conformação Molecular , Solventes
5.
Chem Soc Rev ; 38(12): 3316-25, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20449051

RESUMO

This tutorial review provides a summary of the binding of neutral molecules, cations and anions within helical cavities formed specifically by the folding of unnatural oligomers, called foldamers. Foldamers are emerging as a new class of synthetic receptors whose binding sites are not formed by preorganization of covalent bonds, but rather through the combination of various noncovalent interactions that induce folding and subsequent arrangement of functional groups within a helical cavity. The function of foldamers as synthetic receptors can be tuned by careful selection of modular building blocks displaying the appropriate functionality required for guest complexation. As the molecular toolbox expands to create well-defined helical structures, new and interesting functions emerge. It is the purpose of this review to provide the reader with an introduction to helical cavities formed specifically by foldamers and their subsequent function as molecular and ionic receptors. It will interest the supramolecular, organic and bioorganic communities.


Assuntos
Compostos Macrocíclicos/química , Compostos Macrocíclicos/síntese química , Estrutura Molecular
7.
J Am Chem Soc ; 125(50): 15302-3, 2003 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-14664569

RESUMO

A pair of homologous and soluble reversible polymers display nearly identical solution structures but dramatically different dissociation dynamics (1.0 vs ca. 100 s-1) along their main chains. The polymers are formed by organopalladium-pyridine coordination, and steric effects at the metal center control the dynamics. Importantly, the association constant is not significantly affected by the sterics. The resulting orthogonal control over dissociation kinetics provides a general tool for studying the effects of dynamics independent of thermodynamics in supramolecular systems, particularly main-chain reversible polymers.

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