The relative influence of physical and chemical bonds to overall gel properties are explored in gelatin gels. Physical, chemical, chemical-physical, and physical-chemical gels are obtained by cooling the protein solution and/or by transglutaminase reaction. Each type of network is characterized by rheology and polarimetry. It is shown that the overall properties as well as the dynamics inside the gels are dependent upon the order of formation and on the relative amount of triple helices and covalent bonds. Enzyme hydrolysis of covalent gels is slower than that of physical gels, as confirmed by the kinetics of helix release and degradation. A scheme is proposed to explain the results at both the physicochemical and the molecular levels.
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http://dx.doi.org/10.1021/bm049670d | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Medicine, Huanghe Science and Technology University, Zhengzhou 450061, P. R. China.
Silver nanowire (Ag NW)-based elastic conductors have been considered a promising candidate for key stretchable electrodes in wearable devices. However, the weak interface interaction of Ag NWs and elastic substrates leads to poor durability of electronic devices. For everyday usage, an additional self-healing ability is required to resist scratching and damage.
View Article and Find Full Text PDFNat Chem
January 2025
Key Laboratory of Advanced Marine Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China.
sp-carbon-linked covalent organic frameworks (spc-COFs) are crystalline porous polymers with repeat organic units linked by sp carbons, and have attracted increasing interest due to their robust skeleton and tunable semiconducting properties. Single-crystalline spc-COFs with well-defined structures can represent an ideal platform for investigating fundamental physics properties and device performance. However, the robust olefin bonds inhibit the reversible-reaction-based crystal self-correction, thus yielding polycrystalline or amorphous polymers.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Thoracic Cancer, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, China.
Intracellular delivery of proteins has attracted significant interest in biological research and cancer treatment, yet it continues to face challenges due to the lack of effective delivery approaches. Herein, we developed an efficient strategy cationic α-helical polypeptide-mediated anionic proprotein delivery. The protein was reversibly modified with adenosine triphosphate dynamic covalent chemistry to prepare an anionic proprotein (A-protein) with abundant phosphate groups.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Institute of Organic Chemistry, Materials Science, 345 lingling Road, 200032, Shanghai, CHINA.
Three-dimensional covalent organic frameworks (3D COFs), a class of highly porous crystalline polymers, have exhibited great potentials in many applications. However, the reported topologies of 3D COFs have been limited to high-symmetry crystal systems, which significantly hindered the development of such functional materials. Herein, we demonstrate the first construction of four highly crystalline orthorhombic 3D COFs with an unprecedented fmj topology, based on judiciously choosing rotatable monomers.
View Article and Find Full Text PDFJ Pharm Anal
December 2024
Institute of Infectious Disease and Infection Control, Jena University Hospital, Jena, 07747, Germany.
In our prior research, polymer nanoparticles (NPs) containing tobramycin displayed robust antibacterial efficacy against biofilm-embedded () and (. ) cells, critical pathogens in cystic fibrosis. In the current study, we investigated the deposition of a nanoparticulate carrier composed of poly(d,l-lactic--glycolic acid) (PLGA) and poly(ethylene glycol)--PLGA (PEG-PLGA) that was either covalently bonded with cyanine-5-amine (Cy5) or noncovalently bound with freely embedded cationic rhodamine B (RhB), which served as a drug surrogate.
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