Photothermal Conversion Perylene-Based Metal-Organic Framework with Panchromatic Absorption Bandwidth across the Visible to Near-Infrared.

Recently, facilely designable metal-organic frameworks have gained attention in the construction of photothermal conversion materials. Nonetheless, most of the previously reported photothermal conversion metal-organic frameworks exhibit limited light absorption capabilities. In this work, a distinctive metal-organic framework with heterogeneous periodic alternate spatial arrangements of metal-oxygen clusters and perylene-based derivative molecules was prepared by in situ synthesis.

A nomogram to predict prolonged postoperative ileus after intestinal resection for Crohn's disease.

Purpose: We aim to identify the risk factors of PPOI in patients with CD and create a nomogram for prediction of PPOI for CD.

Methods: Data on 462 patients who underwent partial intestinal resection for CD in Jin-ling Hospital between January 2019 and June 2021 were retrospectively collected. Univariate and multivariate analyses were performed to determine the risk factors for PPOI and we used the risk factors to create a nomogram.

DNA interstrand crosslink repair in mammalian cells: step by step.

Interstrand DNA crosslinks (ICLs) are formed by natural products of metabolism and by chemotherapeutic reagents. Work in E. coli identified a two cycle repair scheme involving incisions on one strand on either side of the ICL (unhooking) producing a gapped intermediate with the incised oligonucleotide attached to the intact strand.

Repair of laser-localized DNA interstrand cross-links in G1 phase mammalian cells.

Interstrand cross-links (ICLs) are absolute blocks to transcription and replication and can provoke genomic instability and cell death. Studies in bacteria define a two-stage repair scheme, the first involving recognition and incision on either side of the cross-link on one strand (unhooking), followed by recombinational repair or lesion bypass synthesis. The resultant monoadduct is removed in a second stage by nucleotide excision repair.

Human embryonic stem cells have enhanced repair of multiple forms of DNA damage.

Embryonic stem cells need to maintain genomic integrity so that they can retain the ability to differentiate into multiple cell types without propagating DNA errors. Previous studies have suggested that mechanisms of genome surveillance, including DNA repair, are superior in mouse embryonic stem cells compared with various differentiated murine cells. Using single-cell gel electrophoresis (comet assay) we found that human embryonic stem cells (BG01, I6) have more efficient repair of different types of DNA damage (generated from H2O2, UV-C, ionizing radiation, or psoralen) than human primary fibroblasts (WI-38, hs27) and, with the exception of UV-C damage, HeLa cells.

Targeted gene knock in and sequence modulation mediated by a psoralen-linked triplex-forming oligonucleotide.

Information from exogenous donor DNA can be introduced into the genome via homology-directed repair (HDR) pathways. These pathways are stimulated by double strand breaks and by DNA damage such as interstrand cross-links. We have employed triple helix-forming oligonucleotides linked to psoralen (pso-TFO) to introduce a DNA interstrand cross-link at a specific site in the genome of living mammalian cells.

Extensive sugar modification improves triple helix forming oligonucleotide activity in vitro but reduces activity in vivo.

We are developing triple helix forming oligonucleotides (TFOs) for gene targeting. Previously, we synthesized bioactive TFOs containing 2'-O-methylribose (2'-OMe) and 2'-O-aminoethylribose (2'-AE) residues. Active TFOs contained four contiguous 2'-AE residues and formed triplexes with high thermal stability and rapid association kinetics.

Psoralen conjugates for visualization of genomic interstrand cross-links localized by laser photoactivation.

DNA interstrand cross-links are formed by chemotherapy drugs as well as by products of normal oxidative metabolism. Despite their importance, the pathways of cross-link metabolism are poorly understood. Laser confocal microscopy has become a powerful tool for studying the repair of DNA lesions that can be detected by immunofluorescent reagents.

Targeted cross-linking of the human beta-globin gene in living cells mediated by a triple helix forming oligonucleotide.

Triple helix forming oligonucleotides (TFOs) may have utility as gene targeting reagents for "in situ" gene therapy of genetic disorders. Triplex formation is challenged by negative charge repulsion between third strand and duplex phosphates, and destabilizing positive charge repulsion between adjacent protonated cytosines within pyrimidine motif third strands. Here we describe the synthesis of TFOs designed to target a site in the human beta-globin gene, which is the locus for mutations that underlie the beta-globinopathies, including sickle cell anemia.

Triplex targeted genomic crosslinks enter separable deletion and base substitution pathways.

We have synthesized triple helix forming oligonucleotides (TFOs) that target a psoralen (pso) interstrand crosslink to a specific chromosomal site in mammalian cells. Mutagenesis of the targeted crosslinks results in base substitutions and deletions. Identification of the gene products involved in mutation formation is important for developing practical applications of pso-TFOs, and may be informative about the metabolism of other interstrand crosslinks.

Structure and activity of D-Pro14 melittin.

D-Pro14 melittin was synthesized to investigate the effect of increasing the angle of the bend in the hinge region between the helical segments of the molecule. Structural analysis by nuclear magnetic resonance indicated that, in methanol, the molecule consisted of two helices separated at Pro14, as in melittin. However, the two helices in D-Pro14 melittin were laterally displaced relative to each other by approximately 7 A, and in addition, there was a small rotation of the carboxyl-terminal helix relative to the amino-terminal helix around the long axis of the molecule.

Protamine-fragment peptides fused to an SV40 nuclear localization signal deliver oligonucleotides that produce antisense effects in prostate and bladder carcinoma cells.

The development of antisense technology has focused on improving methods for oligonucleotide delivery into cells. In the present work, we describe a novel strategy for oligonucleotide delivery based on a bifunctional peptide composed of a C-terminal protamine-fragment that contains a DNA-binding domain and an N-terminal nuclear localization signal sequence derived from the SV40 large-T antigen (The sequences of two of the peptides are R6WGR6-PKKKRKV [s-protamine-NLS] and R4SR6FGR6VWR4-PKKKRKV [l-protamine-NLS]). We demonstrated, by intrinsic fluorescence quenching, that peptides of this class form complexes with oligodeoxynucleotides.