The pure Shupe effect is substantially reduced in a fiber optic gyroscope (FOG) with symmetrical windings. However, the effect of the temperature-induced nonuniformity of the stress in the coil depends on the mean temperature derivative (T-dot). Research on precision winding technology has discovered that the symmetry of optical fiber rings affects the temperature performance of fiber optic gyroscopes.
View Article and Find Full Text PDFPeptide vaccines exhibit great potential in cancer therapy via eliciting antigen-specific host immune response and long-term immune memory to defend cancer cells. However, the low induced immune response of many developing vaccines implies the imperatives for understanding the favorable structural features of efficient cancer vaccines. Herein, we report on the two groups of self-adjuvanting peptide vaccines with distinct morphology and investigate the relationship between the morphology of peptide vaccines and the induced immune response.
View Article and Find Full Text PDFCurrent strategies for the design of antibacterial peptides show limitations in the development of assembled antibacterial peptides due to the challenges in simultaneously balancing the antibacterial activity and assembling behavior. Herein, we report on one strategy for the design of antibacterial peptides derived from virulent amyloids and investigate their self-assembly into nanostructures with remarkable antibacterial activity. The peptides were either directly truncated from virulent amyloid peptide PSM α3 or mutated from the original sequence by replacing the lysine and phenylalanine residues with arginine or tryptophan, leading to three undecapeptides.
View Article and Find Full Text PDFProgrammable self-assembly of peptides into well-defined nanostructures represents one promising approach for bioinspired and biomimetic synthesis of artificial complex systems and functional materials. Despite the progress made over the past two decades in the development of strategies for precise manipulation of the self-assembly of peptides, there is a remarkable gap between current peptide assemblies and biological systems in terms of structural complexity and functions. Here, the concept of peptide tectonics for the creation of well-defined nanostructures predominately driven by the complementary association at the interacting interfaces of tectons is introduced.
View Article and Find Full Text PDFIslet transplantation is one of the most promising therapeutic options that could restore euglycaemia in type 1 diabetic individuals. The currently implemented alginate microsphere islet encapsulation approach has led to positive outcomes in improving intraportal islet delivery in rodents. However, results obtained from human clinical trials remain disappointing.
View Article and Find Full Text PDFPrecise incorporation of functional residues into sequences allows for tailoring the noncovalent interactions between peptides to guide their self-assembly into well-defined nanostructures, thus facilitating creation of artificial functional materials resembling natural systems. Here, we report on the self-assembly of dipeptides consisting of one fluorinated phenylalanine unit (Z residue) and one natural aromatic residue into laminated nanofibers predominately driven by polar-π interactions. On the basis of characterizations using transmission electron microscopy, scanning electron microscopy, atomic force microscopy, circular dichroism, Fourier transform infrared spectroscopy, and thioflavin T binding assay, we found that the face-centered stacking pattern of the dipeptides FZ, ZF, and ZY stabilized by the polar-π interactions and antiparallel β-sheet H-bonding interactions led to lamination of nanofibers and formation of ribbonlike nanostructures.
View Article and Find Full Text PDFCell surface engineering can protect implanted cells from host immune attack. It can also reshape cellular landscape to improve graft function and survival post-transplantation. This protocol aims to achieve surface engineering of pancreatic islets using an ultrathin heparin-incorporated starPEG (Hep-PEG) nanocoating.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
September 2017
Cell surface engineering could protect implanted cells from host immune rejections while modify the cellular landscape for better post-transplantation graft function and survival. Islet transplantation is considered the most promising therapeutic option with the potential to cure diabetes. Current approach to improve clinical efficacy of pancreatic islet transplantation is alginate encapsulation.
View Article and Find Full Text PDFA reductase-cleavable and thermo-responsive star-shaped polymer nanogel was prepared via an "arm-first" atom transfer radical polymerization approach. The nanogel consists of a thermo- and redox-sensitive core and a zwitterionic copolymer block. The dual sensitive core is composed of poly(N-isopropylacrylamide) that is formed by disulfide crosslinking of N-isopropylacrylamide.
View Article and Find Full Text PDFWe report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-D-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using a combination of enzymatic transesterification and emulsion copolymerization for intracellular drug delivery. The nanogel exhibited redox, pH and temperature-responsive properties, which can be adjusted by varying the monomer feeding ratio. Furthermore, the volume phase transition temperature (VPTT) of the nanogels was close to body temperature and can result in rapid thermal gelation at 37 °C.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
January 2014
Novel galactose functionalized thermoresponsive injectable microgels, poly(N-isopropylacrylamide-co-6-O-vinyladipoyl-D-galactose) P(NIPAAm-co-VAGA), have been fabricated using a combination of enzymatic transesterification and emulsion copolymerization. The microgels exhibit reversible temperature-responsive behavior, which can be tuned by varying the monomer feed ratio. The lower critical solution temperatures (LCSTs) of the materials are close to body temperature and can result in a rapid thermal gelation at 37 °C.
View Article and Find Full Text PDFNovel double-hydrophilic thermosensitive statistical glycopolymers, poly(N-isopropylacrylamide-co-6-O-vinyladipoyl-D-glucose), were fabricated using a chemoenzymatic process and free radical copolymerization. The structures of the glycopolymers were confirmed by (1)H and (13)C NMR, and their molar mass distributions determined by gel permeation chromatography. UV-vis spectroscopy data showed that the polymers exhibited reproducible temperature-responsive behavior.
View Article and Find Full Text PDFIn this study, drug-loaded nanofibers were prepared by electrospinning captopril (CPL) with aliphatic biodegradable polyesters. Poly(L-lactic acid) (PLLA), poly(lactic-co-glycolic acid) (PLGA), and poly(lactic-co-ε-caprolactone) (PLCL) were used as filament-forming matrix polymers, and the concentration of CPL in each fiber type was varied. Scanning electron microscopy indicated that the morphology and diameters of the fibers were influenced by the concentration of polymer in the spinning solution and the drug loading.
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