The bifunctional alkylating agent 1,2,3,4-diepoxybutane forms interstrand DNA-DNA cross-links between the N7 positions of deoxyguanosine residues on opposite strands of the duplex. For racemic diepoxybutane, these cross-links predominate within 5'-GNC/3'CNG sequences, where N is any nucleotide. We used denaturing polyacrylamide gel electrophoresis (dPAGE) to examine the role of stereochemistry in the cross-linking reaction, subjecting a restriction fragment to cross-linking with S,S-DEB, R,R-DEB, or meso-DEB. DNA cross-links generated by each isomer were isolated by dPAGE, and the sites of cross-linking were identified by sequencing gel analysis of DNA fragments generated by hot piperidine cleavage. We found that the 5'-GNC consensus sequence of racemic DEB is conserved, but the efficiencies of cross-linking vary, with S,S- > R,R- > meso-DEB. These results help explain the observed differences between the biological activities of DEB stereoisomers.
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http://dx.doi.org/10.1021/tx050250z | DOI Listing |
PLoS One
January 2025
Glycologix, Inc., 100 Cummings Center, Beverly, Massachusetts, United States of America.
Chemical modification of naturally derived glycosaminoglycans (GAGs) expands their potential utility for applications in soft tissue repair and regenerative medicine. Here we report the preparation of a novel crosslinked chondroitin sulfate (~200 to 2000 kilodaltons) that is both soluble in aqueous solution and microfilterable. We refer to these materials as "SuperGAGs.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
February 2025
McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania, USA.
Cardiovascular diseases (CVDs) were responsible for approximately 19 million deaths in 2020, marking an increase of 18.7% since 2010. Biological decellularized patches are common therapeutic solutions for CVD such as cardiac and valve defects.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China.
Fluorescent carbon dots, especially red/near-infrared-emitting CDs, are becoming increasingly important in the field of biomedicine. This article reviews the synthesis, fluorescence mechanisms, and biological applications of R/NIR-CDs, emphasizing the importance of carbon source and solvent selection in controlling their optical properties. The formation process of CDs is classified, and the fluorescence mechanisms of CDs are summarized, involving carbon core states, surface states, molecular states, and cross-linking enhanced emission effects.
View Article and Find Full Text PDFMembranes (Basel)
January 2025
Centre for Advanced 2D Materials, National University of Singapore, Singapore 117546, Singapore.
The large-scale implementation of 2D material-based membranes is hindered by mechanical stability and mass transport control challenges. This work describes the fabrication, characterisation, and testing of self-standing graphene oxide (GO) membranes cross-linked with oxides such as FeO, AlO, CaSO, NbO, and a carbide, SiC. These cross-linking agents enhance the mechanical stability of the membranes and modulate their mass transport properties.
View Article and Find Full Text PDFGels
January 2025
Faculty of Medicine, Dalian University of Technology, Dalian 116033, China.
Peptides can be designed to self-assemble into predefined supramolecular nanostructures, which are then employed as biomaterials in a range of applications, including tissue engineering, drug delivery, and vaccination. However, current self-assembling peptide (SAP) hydrogels exhibit inadequate self-healing capacities and necessitate the use of sophisticated printing apparatus, rendering them unsuitable for 3D printing under physiological conditions. Here, we report a precisely designed charged peptide, Z5, with the object of investigating the impact of electrostatic interactions on the self-assembly and the rheological properties of the resulting hydrogels.
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