Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 696
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Chem Commun (Camb) ; 56(14): 2143-2146, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31970346

RESUMO

In Nature, numerous proteins have evolved to perform similar roles, such as mechanical energy dispersion in different tissues. These biological macromolecules obtain their function from their tertiary structure, but proteins with similar roles can be quite different from each other, making it hard to define what structural features could be mimicked in synthetic materials in order to improve their performance. Here, we introduce an important protein feature - disulphide loops - into synthetic polymers and study the role of the loop size on mechanical energy dispersion. By stressing these polymers in solution, we were able to show, experimentally, that the loop size, up to a certain level, has a significant effect on the chain mechanochemical fragmentation rate, indicating it is affecting the polymer unfolding in solution prior to mechanochemical scission of the polymer backbone. Importantly, this experimental study uses homopolymers, providing information on an individual parameter - loop size - which cannot be obtained from comparing different proteins. This research emphasises the use of tailor-designed polymer-peptide hybrids to study fundamental questions on protein tertiary structures.


Assuntos
Dissulfetos/química , Polímeros/síntese química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular , Polímeros/química
2.
Chem Commun (Camb) ; 56(4): 539-542, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31829317

RESUMO

The first example of supramolecular recognition of phosphocholine by a cavitand receptor has been reported here. The chemical structure of the receptor has been optimized by DFT calculations. The recognition mechanism is based on a "multi-topic approach", which leads to highly efficient (K value up to 107 M-1), selective and sensitive (ppb level) sensing of phosphocholine. The recognition mechanism proposed here is similar to those exploited by Nature, and paves the way for the realization of new sensors with important applications in medicine and security fields.


Assuntos
Complexos de Coordenação/química , Fosforilcolina/análise , Zinco/química , Complexos de Coordenação/síntese química , Teoria da Densidade Funcional , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular
3.
Chem Commun (Camb) ; 55(94): 14119-14122, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31687686

RESUMO

A new strategy to construct a transient supramolecular peptide amphiphile (SPA) and its vesicular aggregates is displayed. The construction of the amphiphile is assisted by the ternary complexation of cucurbit[8]uril and pH responsive imine bond formation. The transient assembly follows a pH clock set by urea/urease and hydrolysis of glucono delta-lactone (GdL). The transient assembly can be repeated for several cycles through feeding the system with the fuel (urea).


Assuntos
Peptídeos/química , Tensoativos/química , Concentração de Íons de Hidrogênio , Hidrólise , Lactonas/química , Lactonas/metabolismo , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular , Peptídeos/síntese química , Tensoativos/síntese química , Ureia/química , Ureia/metabolismo , Urease/química , Urease/metabolismo
4.
Carbohydr Polym ; 225: 115226, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521299

RESUMO

ß-carotene and chitooligosaccharides are bioactive compounds that find their application in the food industry as well in biomedical fields. However, the application of ß-carotene is limited due to its very low water solubility, as well as its air, light and temperature sensitivity. The preparation of ß-carotene-chitooligosaccharides complexes by mechanochemical methods was presented. Their physical and chemical properties including solubility, size, zeta potential and radical scavenging activity were investigated. The interaction of the two components was shown by NMR, FT-IR, and Raman spectroscopy. The complexes were analysed by scanning and transmission electron microscopy. Chitooligosaccharides could serve as a carrier for ß-carotene delivery. The complexation did not cause the loss of the radical scavenging activity of ß-carotene and guaranteed its water solubility.


Assuntos
Quitina/análogos & derivados , Substâncias Macromoleculares , beta Caroteno , Antioxidantes/química , Quitina/química , Quitina/isolamento & purificação , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Solubilidade , Temperatura Ambiente , Água/química , beta Caroteno/química , beta Caroteno/isolamento & purificação
5.
Chem Commun (Camb) ; 55(82): 12388-12391, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31559988

RESUMO

Antibodies are widely used both in clinical practice and in research. However, the development of methods to increase the ratio of antibodies to recognize phosphorylated proteins remains challenging. In this study, we report a novel and useful method for the efficient production of antibodies for phosphorylated proteins. Based on our previously developed vaccine adjuvant Nap-GDFDFDY, we prepared hydrogels by the Ca2+-induced self-assembly of a phosphorylated peptide gelator Nap-GDFDFpDY. The hydrogel could protect phosphorylated antigens from being dephosphorylated by endogenous phosphatase, thus selectively increasing the ratio of the antibodies for phosphorylated proteins. Our study provides a useful strategy for the production of antibodies to recognize proteins with specific posttranslational modifications.


Assuntos
Anticorpos/química , Anticorpos/imunologia , Formação de Anticorpos , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Monoéster Fosfórico Hidrolases/análise , Monoéster Fosfórico Hidrolases/imunologia , Hidrogel de Polietilenoglicol-Dimetacrilato/síntese química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação
6.
Molecules ; 24(17)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480572

RESUMO

A simple and straightforward synthesis of diporphyrins and pentaporphyrins is reported here. The supramolecular interactions of the new porphyrin derivatives with C60 and PyC60 (a pyridyl [60]fulleropyrrolidine) were evaluated by absorption and fluorescence titrations in toluene. While no measurable modifications of the absorption and fluorescence spectra were observed upon addition of C60 to the porphyrin derivatives, the addition of PyC60 to the corresponding mono-Zn(II) porphyrins resulted in the formation of Zn(porphyrin)-PyC60 coordination complexes and the binding constants were calculated. Results show that the four free-base porphyrin units in pentaporphyrin 6 have a significant contribution in the stabilization of the 6-PyC60 complex. The crystal and molecular features of the pentaporphyrin Zn5 were unveiled using single-crystal X-ray diffraction studies.


Assuntos
Fulerenos/química , Substâncias Macromoleculares/química , Porfirinas/síntese química , Cinética , Substâncias Macromoleculares/síntese química , Modelos Moleculares , Porfirinas/química , Espectrometria de Fluorescência , Tolueno/química
7.
Eur J Med Chem ; 182: 111592, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31421632

RESUMO

Twelve 2-(quinolin-4-ylmethylene) hydrazinecarbothioamide derivatives were synthetized and their biological properties were investigated, among which, the ability to interact with DNA and BSA through UV-Vis absorption, fluorescence, Circular Dichroism, molecular docking and relative viscosity, antiproliferative activity against MCF-7 and T-47D mammary tumor cells and RAW-264.7 macrophages and inhibitory capacity of the enzyme topoisomerase IIα. In the binding study with DNA and BSA, all the compounds displayed affinity for interaction with both biomolecules, especially JF-92 (p-ethyl-substituted), with binding constant of 1.62 × 106 and 1.43 × 105, respectively, and DNA binding mode by intercalation. The IC50 values were obtained between 0.81 and 1.48 µM and topoisomerase inhibition results in 10 µM. Thus, we conclude that the reduction of the acridine to quinoline ring did not disrupt the antitumor action and that substitution patterns are important for biomolecule interaction affinity as they demonstrate the potential of these compounds for anticancer therapy.


Assuntos
Antineoplásicos/farmacologia , DNA Topoisomerases Tipo II/metabolismo , Quinolinas/farmacologia , Tiossemicarbazonas/farmacologia , Inibidores da Topoisomerase II/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Células MCF-7 , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Substâncias Macromoleculares/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Modelos Moleculares , Estrutura Molecular , Quinolinas/síntese química , Quinolinas/química , Células RAW 264.7 , Relação Estrutura-Atividade , Tiossemicarbazonas/síntese química , Tiossemicarbazonas/química , Inibidores da Topoisomerase II/síntese química , Inibidores da Topoisomerase II/química , Viscosidade
8.
J Pept Sci ; 25(7): e3176, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31309673

RESUMO

Chiral self-assembly of peptides is of fundamental interest in the field of biology and material science. Protamine, an alkaline biomacromolecule which is ubiquitous in fish and mammalian, plays crucial roles in directing the helical twisting of DNA. Inspired by this, we reported a bioinspired pathway to direct the hierarchical chiral self-assembly of a short synthetic dipeptide. The peptide could self-assemble into negatively charged chiral micelles in water that spontaneously formed a nematic liquid crystalline phase. By incorporation with protamine, the micelles condensed with the protamine into large helical bundles with precisely controlled diameter. Furthermore, to simulate the intracellular environments, we investigated macromolecular crowding on the coassembly of peptide and protamine, which leads to the formation of much thinner helical structures. The results highlight the roles of highly charged biomacromolecules and macromolecular crowding on peptide self-assembly, which are beneficial for the practical applications of self-assembling peptides in biomedicine and sensing.


Assuntos
Nanoestruturas/química , Peptídeos/síntese química , Protaminas/química , Animais , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Micelas , Peptídeos/química , Conformação Proteica em alfa-Hélice
9.
Chem Commun (Camb) ; 55(53): 7639-7642, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31198914

RESUMO

We describe an unexpected, cyclic supramolecular complex that results from self-assembly of the nonsteroidal anti-inflammatory drug, diclofenac and 4,4'-azopyridine. The cycles self-assemble into 1D columns occupied by solvent, which can be removed at elevated temperatures (>100 °C) while retaining crystallinity. The complex exhibits solvent exchange ability that occurs through crystal-to-crystal transformations. Finally, the complex can be synthesized using mechanochemistry. Materials exhibiting the structural framework and robustness described here could be applied to removal of hazardous materials or undesirable solvents.


Assuntos
Anti-Inflamatórios não Esteroides/química , Diclofenaco/química , Anti-Inflamatórios não Esteroides/síntese química , Cristalografia por Raios X , Diclofenaco/síntese química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Modelos Moleculares , Estrutura Molecular
10.
Org Biomol Chem ; 17(28): 6719-6734, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31241089

RESUMO

The following review gives an overview about synthetic peptide-polymer conjugates as macromolecular building blocks and their self-assembly into a variety of supramolecular architectures, from supramolecular polymer chains, to anisotropic 1D arrays, 2D layers, and more complex 3D networks. A selection of recent literature examples using linear, coiled-coil and cyclic peptide motifs is provided. The reversible nature of the unimer-to-supramolecular polymer transition provides unique opportunities to investigate mechanistic aspects of the supramolecular assembly, with respect to the thermodynamic or kinetic parameters and furthermore provides exciting opportunities for non-equilibrium assembly strategies. Using specific examples we also highlight some of the biological or mechanical function that arises from this versatile class of supramolecular biomaterials.


Assuntos
Peptídeos/química , Polímeros/química , Humanos , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular
11.
Chem Pharm Bull (Tokyo) ; 67(8): 772-774, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31105105

RESUMO

A series of chemiluminescent compounds containing a hydrazide group as a nucleophilic functional group has been synthesized. The syntheses were started from chemiluminescent luminol and isoluminol. The linker moiety was easily introduced onto non-nucleophilic exocyclic amino groups of luminol and isoluminol by gentle heating with cyclic acid anhydrides such as glutaric anhydride. The resulting carboxy group was converted to hydrazide by a simple condensation reaction using carbodiimide. Although majority of the synthesized compounds did not emit strong light, a sufficient chemiluminescence intensity was obtained from luminol-amido-C2-hydrazide (L2H) comprising of luminol scaffold with a dimethylene linker. The ability of L2H to form a covalent bond with a macromolecule was further investigated by incubation with oxidized horseradish peroxidase. The analysis on matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) MS revealed that the coupling efficiency of L2H was similar to that of commercially available labelling reagent having a hydrazide group. These results suggested that L2H, the luminol hydrazide containing a dimethylene linker, could be useful for the labelling of macromolecules in the sensitive bioassay such as chemiluminescence immunoassay.


Assuntos
Hidrazinas/química , Medições Luminescentes , Luminol/química , Luminol/síntese química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Modelos Moleculares , Estrutura Molecular
12.
Macromol Rapid Commun ; 40(14): e1900158, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31111995

RESUMO

A new supramolecular system based on halogen-bonded macromolecular substances is presented. Binding and complex formation between a halogen bond acceptor N-benzyl ammonium resorcinarene bromide and a library of polymeric halogen bond donors based on iodotetrafluorophenoxy functionality is shown. The complex formation was confirmed in liquid state by dynamic light scattering and transmission electron microscopy. Spectroscopic measurements in the solid state verify the halogen bonding. In particular, the study shows that both homopolymers and polyethylene glycol block copolymers act as effective halogen bond donors leading to polymer-architecture-dependent complex morphologies.


Assuntos
Calixarenos/química , Halogênios/química , Substâncias Macromoleculares/química , Fenilalanina/análogos & derivados , Polímeros/química , Calixarenos/síntese química , Substâncias Macromoleculares/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fenilalanina/síntese química , Fenilalanina/química , Polímeros/síntese química
13.
Molecules ; 24(9)2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31067770

RESUMO

During the last number of years a variety of crystallization-driven self-assembly (CDSA) processes based on semicrystalline block copolymers have been developed to prepare a number of different nanomorphologies in solution (micelles). We herein present a convenient synthetic methodology combining: (i) The anionic polymerization of 2-vinylpyridine initiated by organolithium functionalized phosphane initiators; (ii) the cationic polymerization of iminophosphoranes initiated by -PR2Cl2; and (iii) a macromolecular nucleophilic substitution step, to prepare the novel block copolymers poly(bistrifluoroethoxy phosphazene)-b-poly(2-vinylpyridine) (PTFEP-b-P2VP), having semicrystalline PTFEP core forming blocks. The self-assembly of these materials in mixtures of THF (tetrahydrofuran) and 2-propanol (selective solvent to P2VP), lead to a variety of cylindrical micelles of different lengths depending on the amount of 2-propanol added. We demonstrated that the crystallization of the PTFEP at the core of the micelles is the main factor controlling the self-assembly processes. The presence of pyridinyl moieties at the corona of the micelles was exploited to stabilize gold nanoparticles (AuNPs).


Assuntos
Substâncias Macromoleculares/química , Nanopartículas Metálicas/química , Micelas , Polímeros/química , Cristalização , Ouro , Substâncias Macromoleculares/síntese química , Compostos Organofosforados/síntese química , Compostos Organofosforados/química , Tamanho da Partícula , Polimerização , Polímeros/síntese química , Polivinil/síntese química , Polivinil/química , Solventes/química
14.
Chem Asian J ; 14(12): 2102-2107, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-30997743

RESUMO

The semi-artificial branched-polysaccharides, amylose-grafted curdlans, were synthesized utilizing an enzymatic polymerization. Both a curdlan main chain and amylose side chains on the polysaccharides maintain the original helical structure as well as the molecular binding ability. Thanks to the difference in their molecular recognition properties between ß-1,3-glucan chain and α-1,4-glucan chain, the amylose-grafted curdlans can provide two different orthogonal binding sites within one polymeric system. When a water-soluble polythiophene was mixed with the amylose-grafted curdlan, the polythiophene was twisted in two different modes and therein, fluorescence energy of the polythiophene wrapped by the amylose side chains was successfully transferred to the polythiophene wrapped by the curdlan main chain. We thus concluded that in the dendritic superstructure of this polysaccharide, a self-organized "Janus-type FRET system" was successfully constructed.


Assuntos
Amilose/química , beta-Glucanas/química , beta-Glucanas/síntese química , Sítios de Ligação , Transferência Ressonante de Energia de Fluorescência , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Polimerização
15.
Carbohydr Polym ; 213: 411-418, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30879686

RESUMO

Despite some efforts have been made in the research of supramolecular hyperbranched polymers (SHPs) self-assemblies, the study which has not been consideration to date is the influence of incoming stimuli-responsive polymer chain on their self-assembly property undergo outer stimuli. The introduction of stimuli-responsive segments which could maintain their hydrophilic property are expected to affect the self-assembly behaviour of SHPs and expand their further biomedical application. In this paper, AB2-type macromolecular monomer, LA-(CD-PDMA)2, which consisted one lithocholic acid (LA) and two ß-cyclodextrin terminated poly(2-(dimethylamino)ethyl methacrylate) segments (CD-PDMA) was synthesized. LA-(CD-PDMA)2 based SHP were obtained based on the host-guest inclusion interactions of CD/LA moietes and with PDMA as pH-responsive hydrophilic chains. As a control to study the influence of incoming PDMA chains, both LA-(CD-PDMA)2 based SHPs-1 and LA-CD2 based SHPs-2 self-assemblies were comparatively investiged through 2D 1H NMR ROESY, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The results suggested that except for the higher drug loading efficiency LA-(CD-PDMA)2 based SHPs-1 pocessing, the release rates of SHPs-1 increased notably at pH 5.0 than that of pH 7.4 due to the repulsion and stretch of protonated PDMA chains while the release rates of SHPs-2 showed no obvious difference. Finally, basic cell experiments demonstrated that the SHPs based self-assemblies can be internalized into cancer cells, indicating their potential application in the drug delivery field.


Assuntos
Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Polímeros/farmacologia , beta-Ciclodextrinas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ácido Litocólico/química , Ácido Litocólico/farmacologia , Células MCF-7 , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Substâncias Macromoleculares/farmacologia , Conformação Molecular , Imagem Óptica , Polímeros/síntese química , Polímeros/química , beta-Ciclodextrinas/química
16.
Yakugaku Zasshi ; 139(2): 157-164, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-30713224

RESUMO

We focused on the crystal structure of cyclodextrin (CD) to develop new solid CD complexes. There are two large spaces in the columnar structure of CD crystals: one inside a CD cavity and another between CD columns. New solid CD complexes can be designed by incorporating guest drugs between the CD columns. We succeeded in preparing a solid drug/[polyethylene glycol (PEG)/γ-CD-polypseudoraxane (PPRX)] complex by a sealed-heating method via the gas phase. A drug/(PEG/γ-CD-PPRX) complex has a structure in which PEGs are included in a γ-CD cavity, and guest drugs are incorporated between the γ-CD columns. Screening by a sealed-heating method determined that a variety of guest drugs with varying molecular size and log P could be incorporated into the spaces between γ-CD columns, following a stoichiometric rule. Another method, via solid phase using cogrinding and subsequent heating, was developed to prepare drug/(PEG/γ-CD-PPRX) complex. This method enabled us to prepare the complex with a thermally unstable drug, as well as a drug/(PEG/α-CD-PPRX) complex not formed using the sealed-heating method. Both the structure and molecular state of each drug in the complexes were characterized by powder X-ray diffraction and solid-state NMR measurements. The dissolution character and thermal stability of the drug incorporated in the complex could be improved by the specific complex formation. The solid CD complexes thus developed have potential for drug-encapsulation and as drug-release carriers, owing to their unique structural and pharmaceutical properties.


Assuntos
Ciclodextrinas/química , Ciclodextrinas/síntese química , Composição de Medicamentos/métodos , Desenho de Drogas , Substâncias Macromoleculares/química , Substâncias Macromoleculares/síntese química , Cristalização , Portadores de Fármacos , Estabilidade de Medicamentos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Temperatura Ambiente , Difração de Raios X
17.
Yakugaku Zasshi ; 139(2): 165-173, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-30713225

RESUMO

Molecular recognition is useful in creating functional supramolecular materials. Non-covalent bond formations, such as host-guest interactions, hydrogen bonding, and electrostatic interaction, are effective tools for introducing various functions and properties into materials. This review focuses on such macroscopic functions as selective molecular adhesion, self-healing, toughness, and the actuation of supramolecular polymeric materials-materials which have potential in pharmaceutical development. These functions have been achieved using reversible bonding between cyclodextrins (CDs; cyclic host molecules) and guest molecules. For example, macroscopic adhesions between host-modified hydrogels and guest-modified hydrogels have been investigated. CD-modified hydrogels were found to show selective adhesion to a guest hydrogel with an appropriate molecular size for the CD cavity, indicating that the host-guest complex formation between the gels led to the adhesive behavior. Surprisingly, polymeric materials having host-guest cross-linking points show both high toughness and flexibility, unlike conventional covalently cross-linked materials. These materials also exhibited self-healing properties, capable of repairing damage to the materials. Furthermore, the supramolecular materials demonstrated macroscopic rapid expansion and contraction driven by external stimuli under wet or semi-dry conditions, in which the supramolecular gels vary the cross-linking density between the polymers accordingly. Different topological gels are able to vary the length of the polymer chain between cross-linking points to show large deformation. Both types of actuators were found to exhibit externally stimulated flexing behaviors. This review summarizes recent advancements in the development of these supramolecular materials, which appear to be promising new components in pharmaceutical science.


Assuntos
Ciclodextrinas/química , Ciclodextrinas/síntese química , Desenho de Drogas , Substâncias Macromoleculares/química , Substâncias Macromoleculares/síntese química , Fenômenos Químicos , Hidrogéis , Estrutura Molecular , Polímeros/química
18.
Org Biomol Chem ; 17(4): 939-944, 2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30629073

RESUMO

We report the synthesis and self-assembly of fluorescent peptide amphiphiles (NBD-PA) composed of a fluorescent NBD probe and a peptide derivative VVAADD with a C12-alkyl-chain as the linker (NBD-C12-VVAADD). The self-assembly of NBD-PA formed beta-sheet structures at neutral pH in aqueous solution, contributed to an ∼10-fold increase in the fluorescence and quantum yield of NBD molecules, and conferred a supramolecular hydrogel with excellent viscoelastic properties, while gel-to-sol transition of NBD-PA occurred rapidly when the pH value was adjusted to strongly alkaline (e.g. pH 11). Through the pH-responsive self-assembly behavior, we further explored the relationship between fluorescence of NBD-PA and pH values. Interestingly, the fluorescence of the NBD-PA system exhibited an excellent sigmoidal function relationship (R2 = 0.9999) with the alkaline pH values, which enabled accurate pH measurement regardless of salt types and ionic strength of solvents. Furthermore, the fluorescence of NBD-PA was fully reversible upon cycles of pH shifts, with the chemical structure of NBD-PA well-maintained throughout the process. These features of NBD-PA would facilitate the design of in situ pH detection systems as well as pH-responsive actuators for various applications in future.


Assuntos
Corantes Fluorescentes/síntese química , Peptídeos/síntese química , Tensoativos/síntese química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Conformação Molecular , Tamanho da Partícula , Peptídeos/química , Propriedades de Superfície , Tensoativos/química
19.
J Colloid Interface Sci ; 533: 375-384, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30172148

RESUMO

We report a self-assembly-based approach for improved iron chelation of small chelators. A model chelator, deferiprone (DFP) is covalently linked to amphiphilic poly(ethylene glycol)-polypeptide block copolymer that can assemble into micelles. The free DFP generally coordinates with iron in a ratiometric manner (3:1). However, the assembly induces DFP packing in the micelle cores, which restricts its conformational freedom. Hence DFP/iron coordination ratio in micelles is reduced (< 3:1), which leads to an enhanced chelation performance of DFP. In addition, the micellar nanocarrier usually exhibits an extended systemic circulation in contrast to the free DFP. The current work opens new avenues for developing novel nanomedicines for iron overload diseases.


Assuntos
Deferiprona/química , Quelantes de Ferro/síntese química , Ferro/química , Quelantes de Ferro/química , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Micelas , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
20.
Macromol Rapid Commun ; 40(1): e1800557, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30216584

RESUMO

Over the last decade, cyclodextrins (CDs) have gained considerable attention as a potential therapeutic intervention in the treatment of the rare genetic condition Niemann-Pick type C disease (NPC). However, the oligosaccharide in its monomeric form suffers from serious side effects, especially from a pharmacokinetic and biodistribution standpoint. CD-based macromolecular systems hold great promise to overcome such limitations and might provide an improved therapeutic approach in reducing cholesterol accumulation in NPC. In the present article, the latest developments and synthetic strategies in the preparation of CD-containing polymers as cholesterol-mopping therapeutic agents in NPC are summarized.


Assuntos
Anticolesterolemiantes/farmacologia , Colesterol/metabolismo , Ciclodextrinas/farmacologia , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Anticolesterolemiantes/síntese química , Anticolesterolemiantes/química , Ciclodextrinas/síntese química , Ciclodextrinas/química , Humanos , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Substâncias Macromoleculares/farmacologia , Doença de Niemann-Pick Tipo C/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA