Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 182
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-32170796

RESUMO

Incorporation of non-equilibrium actions in the sequence of self-assembly processes would be an effective means to establish bio-like high functionality hierarchic assemblies. As a novel methodology beyond self-assembly, nanoarchitectonics, which has as its aim the fabrication of functional materials systems from nanoscopic units through the methodological fusion of nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio-process, has been applied to this strategy. The application of non-equilibrium factors to conventional self-assembly processes is discussed on the basis of examples of directed assembly, Langmuir-Blodgett assembly, and layer-by-layer assembly. In particular, examples of the fabrication of hierarchic functional structures using bio-active components such as proteins or by the combination of bio-components and two-dimensional nanomaterials, are described. Methodologies described in this review article highlight possible approaches using the nanoarchitectonics concept beyond self-assembly for creation of bio-like higher functionalities and hierarchic structural organization.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31566931

RESUMO

Photodynamic therapy (PDT) has been used in the treatment of cancers and other benign diseases for several years in clinic. However, the hypoxia of tumors and the penetration limitation of excitation light to tissues can dramatically reduce the efficacy of PDT to cancers. To overcome these drawbacks, various assembled nanocarriers such as nanoparticles, nanocapsules, nanocrystals, and so on were introduced. The assembled nanocarriers have the ability of loading photosensitizers, delivering O2 into tumors, generating O2 in situ in tumors, as well as turning near-infrared (NIR) light, X-rays, and chemical energy into ultraviolet or visible light. Therefore, it is easy for the nanocarriers to improve the hypoxia microenvironment or increase the treatment depth of cancers, which will improve the efficiency of PDT to some degree. In recent years, a number of investigations were focused on these subjects. We will summarize the advances of nanocarriers in PDT, especially in O2 introduction PDT and deep PDT. The perspectives, challenges, and potential in translation of PDT will also be discussed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

3.
Mater Today (Kidlington) ; 30: 10-16, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31719792

RESUMO

Low biocompatibility or engineerability of conventional inorganic materials limits their extensive application for power harvesting in biological systems or at bio-machine interfaces. In contrast, intrinsically biocompatible peptide self-assemblies have shown promising potential as a new type of ideal components for eco-friendly optoelectronic energy-harvesting devices. However, the structural instability, weak mechanical strength, and inefficient optical or electrical properties severely impede their extensive application. Here, we demonstrate tryptophan-based aromatic dipeptide supramolecular structures to be direct wide-gap semiconductors. The molecular packings can be effectively modulated by changing the peptide sequence. The extensive and directional hydrogen bonding and aromatic interactions endow the structures with unique rigidity and thermal stability, as well as a wide-spectrum photoluminescence covering nearly the entire visible region, optical waveguiding, temperature/irradiation-dependent conductivity, and the ability to sustain quite high external electric fields. Furthermore, the assemblies display high piezoelectric properties, with a measured open-circuit voltage of up to 1.4 V. Our work provides insights into using aromatic short peptide self-assemblies for the fabrication of biocompatible, miniaturized electronics for power generation with tailored semiconducting optoelectronic properties and improved structural stability.

4.
Chem Commun (Camb) ; 55(100): 15057-15060, 2019 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-31777882

RESUMO

We report a novel nanophotosensitizer via one-step covalent assembly of dopamine and genipin. This is the first report unveiling the photodynamic effect of dopamine-based materials. These nanophotosensitizers can also act as pH-responsive drug nanocarriers via a catechol-boronate linkage, thus achieving combined PDT and chemotherapy for highly efficient cancer treatment.


Assuntos
Dopamina/química , Portadores de Fármacos/química , Nanopartículas/química , Fármacos Fotossensibilizantes/química , Ácidos Borônicos/química , Catecóis/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Oxigênio Singlete/metabolismo
5.
ACS Nano ; 13(12): 14477-14485, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31755683

RESUMO

The formation of ordered nanostructures by metabolites is gaining increased interest due to the simplicity of the building blocks and their natural occurrence. Specifically, aromatic amino acids possess the ability to form ordered supramolecular interactions due to their limited solubility in aqueous solution. Unexpectedly, l-tyrosine (l-Tyr) is almost 2 orders of magnitude less soluble in water compared to l-phenylalanine (l-Phe). However, the underlying mechanism is not fully understood as l-Tyr is more polar. Here, we explore the utilization of insoluble tyrosine assemblies for technological applications and their molecular basis by manipulating the basic building blocks of tightly packed dimers. We show that the addition of an amyloid inhibition agent increases l-Tyr solubility due to the disruption of the dimer formation. The molecular organization grants the l-Tyr crystal higher thermal stability and mechanical properties between three amino acids. Additionally, l-Tyr crystals are shown to generate high and stable piezoelectric power outputs under mechanical pressure in a sandwich device. By incorporating the rigid l-Tyr crystals into a soft polymer, a mechano-responsive bending composite was fabricated. Furthermore, the l-Tyr crystalline needles exhibit an active photowaveguiding property, making them promising candidates for the generation of photonic biomaterial-based devices. The present work exemplifies a feasible strategy to explore physical properties of supramolecular self-assemblies comprises minimalistic naturally occurring building blocks and their applications in energy harvesting, photonic devices, stretchable electronics, and soft robotics.

6.
Chem Commun (Camb) ; 55(87): 13136-13139, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31617550

RESUMO

We explore a facile approach to construct dipeptide-based building blocks containing π-conjugated bridges by using biocross-linkers. Well-defined nanostructures can be assembled and tuned by using different solvents. Compared to pristine units, such dipeptide-based assemblies exhibit structure-dependent and remarkably enhanced optoelectronic properties.


Assuntos
Dipeptídeos/química , Nanoestruturas/química , Estimulação Elétrica , Estrutura Molecular , Fenômenos Ópticos , Tamanho da Partícula , Solventes/química , Propriedades de Superfície
7.
J Colloid Interface Sci ; 557: 628-634, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31557583

RESUMO

Molecular assemblies of cationic dipeptide-gold nanoparticle (CDP-AuNP) hybrid microspheres were used to modify cholesterol oxidase electrodes for high-sensitivity cholesterol detection. The cationic dipeptide used here serves as a functional molecule for adsorbing chloroauric acid based on electrostatic interactions and assembly into spherical structures, providing a platform for loading gold nanoparticles (AuNPs), increasing the immobilization load of the enzyme and maintaining the activity of the enzyme as a result of excellent biocompatibility. Moreover, the CDP-AuNP modified cholesterol oxidase electrode has a higher electrocatalytic activity to cholesterol with obvious enhancement in the current response, exhibiting a current response 13 times higher than that of the controlled electrode. The outstanding biocompatibility and increased enzyme load by hybrid microspheres and the good charge-transfer ability of AuNPs in the peptide-based electrode indicate a very attractive perspective in the field of biodevices.

8.
Chem Soc Rev ; 48(16): 4387-4400, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31237282

RESUMO

Bioinspired nanostructures can be the ideal functional smart materials to bridge the fundamental biology, biomedicine and nanobiotechnology fields. Among them, short peptides are among the most preferred building blocks as they can self-assemble to form versatile supramolecular architectures displaying unique physical and chemical properties, including intriguing optical features. Herein, we discuss the progress made over the past few decades in the design and characterization of optical short peptide nanomaterials, focusing on their intrinsic photoluminescent and waveguiding performances, along with the diverse modulation strategies. We review the complicated optical properties and the advanced applications of photoactive short peptide self-assemblies, including photocatalysis, as well as photothermal and photodynamic therapy. The diverse advantages of photoactive short peptide self-assemblies, such as eco-friendliness, morphological and functional flexibility, and ease of preparation and modification, endow them with the capability to potentially serve as next-generation, bio-organic optical materials, allowing the bridging of the optics world and the nanobiotechnology field.


Assuntos
Nanoestruturas/química , Peptídeos/química , Catálise , Glucose/análise , Humanos , Hidrogéis/química , Luz , Neoplasias/tratamento farmacológico , Fotoquimioterapia , Porfirinas/química , Porfirinas/uso terapêutico
9.
Angew Chem Int Ed Engl ; 58(32): 11072-11077, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31166060

RESUMO

A gel-to-crystal phase transition of a dipeptide supramolecular assembly mediates active water transportation in oils. The addition of water into ultrafast-assembling dipeptide organogels can induce a lamellar-to-hexagonal structural transformation of dipeptide molecular arrangement. Consequently, a phase transition from gel to crystal occurs and in turn water is transported in the dipeptide crystal via well-defined channels. On a macroscopic scale, water transport in the bulk system exhibits an anisotropic characteristic, which can be tuned by the presence of ions in the Hofmeister series. These favorable features enable the automatic separation of dispersed nanoparticles from dissolved electrolytes in aqueous solution. These findings demonstrate the potential of this assembled system for active filtration without external pressure.

10.
J Colloid Interface Sci ; 549: 9-15, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31015057

RESUMO

Photothermal therapy (PTT) based on photothermal effect of the gold nanostructures, has been widely applied as a noninvasive therapy approach in cancer treatment. However, bare Au nanoparticles are not stable enough during the irradiation process, and cannot harvest sufficient energy to kill tumor cells. To improve this, we have fabricated a stable bioagent by loading gold nanorods (AuNRs) into multicompartment mesoporous silica nanoparticles (MMSNs) for the photothermal therapy. The procedure is that when AuNRs entrapped in MMSNs are irradiated by a laser in the near-infrared region of 808 nm, the hyperthermia produced by the assembled composites is strong enough to damage tumor tissues directly. Both experiments in vitro and in vivo demonstrate that the nanocomposites are perfect candidates as PTT agents for the cancer treatment with a high efficiency. Furthermore, it is found that the nanocomposites have good photostability and consistent temperature fluctuation over 11 on/off cycles with irradiation which the pure AuNRs will not have.


Assuntos
Antineoplásicos/química , Ouro/química , Nanocompostos/química , Nanotubos/química , Dióxido de Silício/química , Animais , Antineoplásicos/efeitos da radiação , Antineoplásicos/uso terapêutico , Carbonato de Cálcio/química , Sobrevivência Celular/efeitos dos fármacos , Humanos , Luz , Células MCF-7 , Masculino , Camundongos Endogâmicos BALB C , Nanocompostos/efeitos da radiação , Nanocompostos/uso terapêutico , Nanotubos/efeitos da radiação , Tamanho da Partícula , Fototerapia/métodos , Porosidade , Propriedades de Superfície
11.
Acc Chem Res ; 52(6): 1623-1631, 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-30882207

RESUMO

Molecular machines are an important and emerging frontier in research encompassing interdisciplinary subjects of chemistry, physics, biology, and nanotechnology. Although there has been major interest in creating synthetic molecular machines, research on natural molecular machines is also crucial. Biomolecular motors are natural molecular machines existing in nearly every living systems. They play a vital role in almost every essential process ranging from intracellular transport to cell division, muscle contraction and the biosynthesis of ATP that fuels life processes. The construction of biomolecular motor-based biomimetic systems can help not only to deeply understand the mechanisms of motor proteins in the biological process but also to push forward the development of bionics and biomolecular motor-based devices or nanomachines. From combination of natural biomolecular motors with supramolecular chemistry, great opportunities could emerge toward the development of intelligent molecular machines and biodevices. In this Account, we describe our efforts to design and reconstitute biomolecular motor-based active biomimetic systems, in particular, the combination of motor proteins with layer-by-layer (LbL) assembled cellular structures. They are divided into two parts: (i) reconstitution of rotary molecular motor FOF1-ATPase, which is coated on the surface of LbL assembled microcapsules or multilayers and synthesizes adenosine triphosphate (ATP) through creating a proton gradient; (ii) molecular assembly of linear molecular motors, the kinesin-based active biomimetic systems, which are coated on a planar surface or LbL assembled tubular structure and drive the movement of microtubules. LbL assembled structures offer motor proteins with an environment that resembles the natural cell. This enables high activity and optimized function of the motor proteins. The assembled biomolecular motors can mimic their functionalities from the natural system. In addition, LbL assembly provides facile integration of functional components into motor protein-based active biomimetic systems and achieves the manipulation of FOF1-ATPase and kinesin. For FOF1-ATPase, the light-driven proton gradient and controlled ATP synthesis are highlighted. For kinesin, the strategies used for the direction and velocity control of kinesin-based molecular shuttles are discussed. We hope this research can inspire new ideas and propel the actual applications of biomolecular motor-based devices in the future.

12.
Adv Sci (Weinh) ; 6(5): 1801678, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30886797

RESUMO

Morphologically discrete nanoarchitectures, which mimic the structural complexity of biological systems, are an increasingly popular design paradigm in the development of new nanomedical technologies. Herein, engineered polymeric stomatocytes are presented as a structural and functional mimic of red blood cells (RBCs) with multifunctional therapeutic features. Stomatocytes, comprising biodegradable poly(ethylene glycol)-block-poly(D,L-lactide), possess an oblate-like morphology reminiscent of RBCs. This unique dual-compartmentalized structure is augmented via encapsulation of multifunctional cargo (oxygen-binding hemoglobin and the photosensitizer chlorin e6). Furthermore, stomatocytes are decorated with a cell membrane isolated from erythrocytes to ensure that the surface characteristics matched those of RBCs. In vivo biodistribution data reveal that both the uncoated and coated nano-RBCs have long circulation times in mice, with the membrane-coated ones outperforming the uncoated stomatoctyes. The capacity of nano-RBCs to transport oxygen and create oxygen radicals upon exposure to light is effectively explored toward photodynamic therapy, using 2D and 3D tumor models; addressing the challenge presented by cancer-induced hypoxia. The morphological and functional control demonstrated by this synthetic nanosystem, coupled with indications of therapeutic efficacy, constitutes a highly promising platform for future clinical application.

13.
Angew Chem Int Ed Engl ; 58(22): 7254-7258, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-30912208

RESUMO

Great success has been achieved in recent years in the development of synthetic or assembled nanobiomaterials. Among these, biomolecule-based nanoarchitectures with special optical property are of particular interest. Here, we demonstrate that vitamin B2 nanocrystals assembled as nanorods can be obtained with precise control. Excitingly, such one-dimensional nanostructures not only exhibit intrinsic optical waveguiding properties but also the ability to sensitize oxygen to produce reactive oxygen species. With these properties, we applied the obtained vitamin B2 nanorods under remotely localized light illumination into single tumour cells in vitro for anticancer photodynamic therapy. Further, vitamin B2 nanorods were explored for in vivo photodynamic therapy by using a tumour model. With such bionanostructures, new features and functions of vitamin B2 and its derivatives have been developed.

14.
Angew Chem Int Ed Engl ; 58(13): 4184-4188, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-30701642

RESUMO

We report a thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) brush functionalized Janus Au-Pt bimetallic micromotor capable of modulating the direction of motion with the change of the ambient temperature. The PNIPAM@Au-Pt micromotor moved along the Au-Pt direction with a speed of 8.5 µm s-1 in 1.5 % H2 O2 at 25 °C (below the lower critical solution temperature (LCST) of PNIPAM), whereas it changed the direction of motion (i.e., along the Pt-Au direction) and the speed decreased to 2.3 µm s-1 at 35 °C (above LCST). Below LCST, PNIPAM brushes grafted on the Au side were hydrophilic and swelled, which permitted the electron transfer and proton diffusion on the Au side, and thus the motion is regarded as a self-electrophoretic mechanism. However, PNIPAM brushes above LCST became hydrophobic and collapsed, and thus the driving mechanism switched to the self-diffusiophoresis like that of Pt-modified Janus silica motors. These motors could reversibly change the direction of motion with the transition of the hydrophobic and hydrophilic states of the grafted PNIPAM brushes. Such a thermoresponsive polymer brush functionalization method provides a new strategy for engineering the kinematic behavior of phoretically driven micro/nanomotors.

15.
Angew Chem Int Ed Engl ; 58(17): 5572-5576, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30801929

RESUMO

Multiple-enzyme-involving cascade reactions that yield bioenergy are necessary in natural oxidative phosphorylation. However, in vitro applications are hampered by the sensitivity of catalytic activity to environmental adaptation. Herein, we explore nanozyme-catalyzed cascade reactions in an assembled hybrid architecture for mitochondria-mimicking oxidative phosphorylation. Hollow silica microspheres containing trapped gold nanoparticles were synthesized to promote two enzyme-like catalytic reactions that transform glucose into gluconic acid in the presence of oxygen. The resulting transmembrane proton gradient drives natural ATP synthase reconstituted on the surface to convert ADP and inorganic phosphate into ATP. The assembled architecture possesses high activity for oxidative phosphorylation, comparable to that of natural mitochondria. This study provides a new natural-artificial hybrid prototype for exploring bioenergy supply systems and holds great promise for ATP-powered bioapplications.

16.
Adv Mater ; 31(12): e1807481, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30706551

RESUMO

Peptide assemblies are ideal components for eco-friendly optoelectronic energy harvesting devices due to their intrinsic biocompatibility, ease of fabrication, and flexible functionalization. However, to date, their practical applications have been limited due to the difficulty in obtaining stable, high-performance devices. Here, it is shown that the tryptophan-based simplest peptide cyclo-glycine-tryptophan (cyclo-GW) forms mechanically robust (elastic modulus up to 24.0 GPa) and thermally stable up to 370 °C monoclinic crystals, due to a supramolecular packing combining dense parallel ß-sheet hydrogen bonding and herringbone edge-to-face aromatic interactions. The directional and extensive driving forces further confer unique optical properties, including aggregation-induced blue emission and unusual stable photoluminescence. Moreover, the crystals produce a high and sustained open-circuit voltage (1.2 V) due to a high piezoelectric coefficient of 14.1 pC N-1 . These findings demonstrate the feasibility of utilizing self-assembling peptides for fabrication of biointegrated microdevices that combine high structural stability, tailored optoelectronics, and significant energy harvesting properties.

17.
Nano Lett ; 19(3): 1821-1826, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30768274

RESUMO

As a noninvasive treatment, photodynamic therapy (PDT) is a promising strategy against tumors. It is based on photosensitizer (PS)-induced phototoxicity after irradiation. However, most clinically approved PSs will be widely distributed in normal tissues, especially in the skin, where they will induce phototoxicity on exposure to light. Therefore, patients must remain in a dark room for up to several weeks during or after a PDT. Herein, we proposed a strategy of aggregation-induced emission PSs (AIE-PSs) entrapped in liposomes with controlled photosensitization. The AIE-PSs begin to lose their photosensitivity when entrapped in liposomes. After liposomes have carried AIE-PSs into tumor tissues, the AIE-PSs will be released and immediately reaggregate in a targeted area as the liposomes are decomposed. Their photosensitivity can be triggered at turn-on state and induce cytotoxicity. Two different types of AIE molecules were synthesized and entrapped by liposomes, respectively, to verify the PDT features against tumors in vitro and in vivo. The results indicate that, using this strategy, the photosensitivity of AIE-PS can be controlled and PDT can be treated under normal working conditions, not necessarily in a dark room.

18.
Langmuir ; 35(26): 8557-8564, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-30759988

RESUMO

Layer-by-layer (LbL) assembly is a most commonly used method to prepare various microcapsules based on the electrostatic interactions, hydrogen bonding, covalent bonding, and so on. Among these interactions, Schiff base bond formed in covalent assembly not only has an advantage in stability, but also enables the assembled microcapsules with autofluorescence and pH sensitivity. In this Article, we will mainly describe the construction of biomimetic microcapsules through Schiff base mediated LbL assembly. The structures and properties of the assembled microcapsules are introduced and their applications as drug carriers are highlighted.

19.
J Colloid Interface Sci ; 535: 325-330, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30316119

RESUMO

At present, photophosphorylation in natural or artificial systems is accomplished by the production of protons or their pumping across the biomembranes. Herein, different from this strategy above, we demonstrate a designed system which can effectively enhance photophosphorylation by photo-induced proton-scavenging through molecular assembly. Upon the introduction of photobase generators, a (photo-) chemical reaction occurs to produce hydroxyl ions. Accompanying the further extramembranous acid-base neutralization reaction, an outbound flow of protons is generated to drive the reconstituted adenosine triphosphate (ATP) synthase to produce ATP. That is, contrary to biochemistry, the proton gradient to drive photophosphorylation derives from the scavenging of protons present in the external medium by hydroxyl ions, produced by the partially photo-induced splitting of photobase generator. Such assembled system holds great potential in ATP-consuming bioapplications.


Assuntos
Complexos de ATP Sintetase/metabolismo , Trifosfato de Adenosina/biossíntese , Hidróxidos/síntese química , Nanoestruturas/química , Prótons , Trifosfato de Adenosina/química , Hidróxidos/química , Tamanho da Partícula , Fosforilação , Processos Fotoquímicos , Propriedades de Superfície
20.
Angew Chem Int Ed Engl ; 58(3): 796-800, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30474178

RESUMO

Prototypes of natural biosystems provide opportunities for artificial biomimetic systems to break the limits of natural reactions and achieve output control. However, mimicking unique natural structures and ingenious functions remains a challenge. Now, multiple biochemical reactions were integrated into artificially designed compartments via molecular assembly. First, multicompartmental silica nanoparticles with hierarchical structures that mimic the chloroplasts were obtained by a templated synthesis. Then, photoacid generators and ATPase-liposomes were assembled inside and outside of silica compartments, respectively. Upon light illumination, protons produced by a photoacid generator in the confined space can drive the liposome-embedded enzyme ATPase towards ATP synthesis, which mimics the photophosphorylation process in vitro. The method enables fabrication of bioinspired nanoreactors for photobiocatalysis and provides insight for understanding sophisticated biochemical reactions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA