[Show abstract][Hide abstract] ABSTRACT: Heparin (HEP) and periodate-oxidized heparin (O-HEP) nanotubes were prepared by combining the template method with a layer-by-layer (LbL) technique. The tubular structure was obtained and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM). O-HEP is one of the HEP derivatives that contains anticoagulant activity and preserves its ability for other effects. Chitosan (CHI) and O-HEP have been used to fabricate nanotubes by covalent cross-linking Schiff base reactions. It is demonstrated that the obtained nanotubes have the significant feature of autofluorescence without the addition of any fluorescent dyes and they retain their anticoagulation activity. Compared with O-HEP/CHI nanotubes, HEP/CHI nanotubes show high anticoagulation activity and do not have autofluorescence. Furthermore, this method could be extended to other copolysaccharide derivatives for the preparation of autofluorescent nanomaterials.
Chemistry - An Asian Journal 01/2012; 7(1):127-32. DOI:10.1002/asia.201100425 · 4.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The self-assembly of molecules into desired architectures is currently a challenging subject for the development of supramolecular chemistry. Here we present a facile "breath figure" assembly process through the use of the self-assembled peptide building block diphenylalanine (L-Phe-L-Phe, FF). Macroporous honeycomb scaffolds were fabricated, and average pore size could be regulated, from (1.00±0.18) μm to (2.12±0.47) μm, through the use of different air speeds. It is indicated that the honeycomb formation is humidity-, solvent-, concentration-, and substrate-dependent. Moreover, water molecules introduced from "breath figure" intervene in the formation of hydrogen bonds during FF molecular self-assembly, which results in a hydrogen bond configuration transition from antiparallel β sheet to parallel β sheet. Meanwhile, as a result of the higher polarity of water molecules, the FF molecular array is transformed from laminar stacking into a hexagonal structure. These findings not only elucidate the FF molecule self-assembly process, but also strongly support the mechanism of breath figure array formation. Finally, human embryo skin fibroblast (ESF) culture experiments suggest that FF honeycomb scaffolds are an attractive biomaterial for growth of adherent cells with great potential applications in tissue engineering.
Chemistry - A European Journal 04/2011; 17(15):4238-45. DOI:10.1002/chem.201003021 · 5.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human serum albumin (HSA) patterns constructed on glass substrate by the micro-contact printing (microCP) technique are fabricated to support phospholipids membranes functionalized with biotinylated lipid. The experiment results indicate that this kind of lipid membrane has been assembled on HSA patterns with good stability. And the streptavidin-coated PS microspheres can be deposited on such lipid patterns with high efficiency. In this way, it may create a route to change the biological interface in the fabrication of biosensor.
Journal of Nanoscience and Nanotechnology 10/2010; 10(10):6318-23. DOI:10.1166/jnn.2010.2527 · 1.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Micro- and nanostructures fabricated from biological building blocks have attracted tremendous attention owing to their potential for application in biology and in nanotechnology. Many biomolecules, including peptides and proteins, can interact and self-assemble into highly ordered supramolecular architectures with functionality. By imitating the processes where biological peptides or proteins are assembled in nature, one can delicately design and synthesize various peptide building blocks composed of several to dozens of amino acids for the creation of biomimetic or bioinspired nanostructured materials. This tutorial review aims to introduce a new kind of peptide building block, the diphenylalanine motif, extracted with inspiration of a pathogenic process towards molecular self-assembly. We highlight recent and current advances in fabrication and application of diphenylalanine-based peptide nanomaterials. We also highlight the preparation of such peptide-based nanostructures as nanotubes, spherical vesicles, nanofibrils, nanowires and hybrids through self-assembly, the improvement of their properties and the extension of their applications.
Chemical Society Reviews 06/2010; 39(6):1877-90. DOI:10.1039/b915765b · 33.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper presents a strategy for the biofunctionalization of novel photosensitizer carriers, mesoporous silica nanoparticles (MSNs). After being calcined and absorbed with photosensitizers (hypocrellin B, HB), MSNs can be coated with a lipid layer. Transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM) results proved that HB molecules can be loaded into MSN porous and lipid can coated on the surface of the nanoparticles. When co-cultured with cancer cells (MCF-7), MSNs can transport HB molecules into cells and present low cytotoxicity. With the introduction of a lipid layer, the efficiency of MSN uptake by cells can be improved. These intracellular HB-loaded MSN materials also present cytotoxicity to MCF-7 cells after light irradiation which indicates the materials can be used as good photosensitizer carriers in photodynamic therapy.
[Show abstract][Hide abstract] ABSTRACT: Silver nanochains composed of nanoparticles were prepared by photoreduction in situ under assistance of a helical self-assembly originating from coordination of Congo red and Ag(+). The special hierarchical nanostructures with different surface plasma resonance compared with silver nanoparticles have potential applications for electrical nanodevices.
Chemical Communications 04/2010; 46(13):2310-2. DOI:10.1039/b924724f · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: (Figure Presented) Versatile hybrid colloidal spheres, selfassembled through the association of cationic peptide and polyoxometalate clusters, are not only responsive towards external stimuli but also show novel, adaptive inclusion properties. The adaptive nature of hybrid colloidal spheres is utilized to encapsulate a wide variety of guest materials ranging from watersoluble molecules to hydrophobic nanoparticles and hydrophilic inorganic nanoparticles.
[Show abstract][Hide abstract] ABSTRACT: Organogels that are self-assembled from simple peptide molecules are an interesting class of nano- and mesoscale soft matter with simplicity and functionality. Investigating the precise roles of the organic solvents and their effects on stabilization of the formed organogel is an important topic for the development of low-molecular-weight gelators. We report the structural transition of an organogel self-assembled from a single dipeptide building block, diphenylalanine (L-Phe-L-Phe, FF), in toluene into a flower-like microcrystal merely by introducing ethanol as a co-solvent; this provides deeper insights into the phase transition between mesostable gels and thermodynamically stable microcrystals. Multiple characterization techniques were used to reveal the transitions. The results indicate that there are different molecular-packing modes formed in the gels and in the microcrystals. Further studies show that the co-solvent, ethanol, which has a higher polarity than toluene, might be involved in the formation of hydrogen bonds during molecular self-assembly of the dipeptide in mixed solvents, thus leading to the transition of organogels into microcrystals. The structural transformation modulated by the co-solvent might have a potential implication in controllable molecular self-assembly.
Chemistry - A European Journal 03/2010; 16(10):3176-83. DOI:10.1002/chem.200902139 · 5.73 Impact Factor