Boronic acid-functionalized magnetic porphyrin-based covalent organic framework for selective enrichment of cis-diol-containing nucleosides.

In this study, a novel boronic acid-functionalized magnetic porphyrin-based covalent organic framework (COF) with a core-shell structure was designed and synthesized for the selective enrichment and detection of nucleosides. Firstly, brominated porphyrin-based COF was in situ grown on Fe3O4-NH2 nanospheres (denoted as Fe3O4@Br-COF), then a post-synthetic modification strategy was used to introduce boronic acid into the framework via Suzuki-Miyaura cross-coupling reaction to obtain boronic acid functionalized magnetic COF (denoted as Fe3O4@BA-COF). Suzuki-Miyaura cross-coupling possesses the advantages of mild synthesis conditions, high tolerance to functionalities, and ease of handling and separation, which is considered as a promising candidate for functionalizing COF. It is worth mentioning that the porphyrin-based COF possesses a unique nitrogen-rich skeleton and "trap" structure formed by four pyrrole rings, which can provide hydrogen bond and make it more suitable for trapping analytes than other types of COF. The boronic acid group provides boronate affinity, which enables better selective enrichment of cis-diol-containing nucleoside. The morphology and structure of the prepared Fe3O4@BA-COF was characterized by various methods. Based on the Fe3O4@BA-COF, a facile magnetic solid phase extraction coupled with high performance liquid chromatography method (MSPE-HPLC) was used to extract and detect adenosine, guanosine, uridine, and cytidine in urine samples. This work not only provides a mild and feasible post-synthetic modification method for fabrication of boronic acid-functionalized magnetic COF, but also provides an efficient and rapid method to selectively enrich and detect hydrophilic nucleosides.

Identification and characterization of shark VNARs targeting the Helicobacter pylori adhesin HpaA.

Helicobacter pylori (H. pylori) is recognized as a pathogen associated with several gastrointestinal diseases. The current treatments exhibit numerous drawbacks, including antibiotic resistance. H. pylori can adhere to and colonize the gastric mucosa through H. pylori adhesin A (HpaA), and antibodies against HpaA may be an effective therapeutic approach. The variable domain of immunoglobulin new antigen receptor (VNAR) is a novel type of single-domain antibody with a small size, good stability, and easy manufacturability. This study isolated VNARs against HpaA from an immune shark VNAR phage display library. The VNARs can bind both recombinant and native HpaA proteins. The VNARs, 2A2 and 3D6, showed high binding affinities to HpaA with different epitopes. Furthermore, homodimeric bivalent VNARs, biNb-2A2 and biNb-3D6, were constructed to enhance the binding affinity. The biNb-2A2 and biNb-3D6 had excellent stability at gastrointestinal pH conditions. Finally, a sandwich ELISA assay was developed to quantify the HpaA protein using BiNb-2A2 as the capture antibody and BiNb-3D6 as the detection antibody. This study provides a potential foundation for novel alternative approaches to treatment or diagnostics applications of H. pylori infection.

Ten-year outcomes after percutaneous coronary intervention versus coronary artery bypass grafting for multivessel or left main coronary artery disease: a systematic review and meta-analysis.

BACKGROUND: Short-term and long-term comparative outcomes after percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for multivessel coronary artery (MVCA) or left main coronary artery (LMCA) disease are highly debated. GOALS: We performed a meta-analysis to evaluate the difference between PCI and CABG for the treatment of patients with MVCA or LMCA in long-term follow-up. METHODS: Literatures were searched in PubMed, EMBASE and The Cochrane Library from January 1, 2000 to January 1, 2021, including RCTs and observational studies (OSs). The primary outcome was all-cause mortality at 10 years follow-up, and the secondary outcomes included cardiac mortality, repeated revascularization, myocardial infarction, and stroke. RESULTS: A total of 5 RCTs reporting data from 3013 participants and 4 OSs of 5608 participants were included for analysis. There was no significant difference between PCI and CABG in all-cause mortality (Odds Ratio (OR) 1.03 [95% confidence interval (CI) 0.89 to 1.19]), whereas PCI was associated with higher cardiac mortality (OR 0.76 [95% CI 0.65 to 0.90]) and repeated revascularization rate comparing to CABG (OR 1.77 [95% CI 1.08 to 2.89]; I2 = 94.61%). The difference between PCI and CABG in repeated revascularization in either RCTs or OSs, in myocardial infarction in either RCTs or OSs were not significant. In OSs, stroke rate in PCI group was lower than those in CABG, but not in RCTs. There was a significant increase of stroke rate in CABG comparing to PCI (OR 0.65 [95% CI 0.53 to 0.80]; I2 = 0.00%). No significant difference between PCI and CABG in myocardial infarction was not observed (OR 0.92 [95% CI 0.64 to 1.31]; I2 = 57.84%). CONCLUSION: Evidence from our study and prior studies suggested the superiority of CABG over PCI in improving 5- but not 10-year survival among patients with MVCA. In the contrast, there was no significant difference between CABG and PCI for treating patients with LMCA in either 5- or 10-year survival rate. More long-term trials are needed to better define differences of outcome between 2 techniques.

Boronic acid grafted metal-organic framework for selective enrichment of cis-diol-containing compounds.

This study constructed boronic acid grafted Zr-MOF (BA-Zr-MOF) by a simple pre-installation strategy through mixed organic ligands. Typically, BA-Zr-MOF was prepared by one-step hydrothermal method used for enrichment of cis-diol-containing nucleosides through pipette tip solid-phase extraction (PT-SPE) followed by detection of high-performance liquid chromatography. It is worth mentioning that BA is well assembled into MOF and cis-diol-containing compounds can be efficiently and selectively enriched by abundant boronic acid groups. Three groups of different types of compounds were used to evaluate their selectivity and the results showed the excellent selectivity to cis-diol-containing compounds of as-prepared adsorbent. The BA-Zr-MOF adsorbent possesses a high adsorption capacity, which can reach 86.40 mg g-1 for adenosine. Under the optimal extraction condition, a PT-SPE-HPLC method based on BA-Zr-MOF for analysis of nucleosides was established. The linear range of the four nucleosides is 0.01 to 50 µg mL-1 with R2 ≥ 0.99 and the detection limits (LODs) are estimated at between 0.005-0.012 µg mL-1. The recoveries in urine were used to test the reliability of the analytical methods, which ranged from 82.8% to 117.1%, with intra-day relative standard deviations (RSDs) ranged from 0.1% to 4.2% and the inter-day RSDs ranged from 0.2% to 6.2%. All the results show that the pre-installation strategy based on dual ligands is an alternative to fabricate MOF composite material and BA-Zr-MOF is a promising material for the analysis of cis-diol-containing biomolecules.

In-situ growth of boronic acid-decorated metal-organic framework on Fe3O4 nanospheres for specific enrichment of cis-diol containing nucleosides.

In this study, a novel core-shell structured magnetic metal-organic framework nanospheres (Fe3O4@PD@BA-Zr-MOF) were fabricated by in-situ growth of boronic acid-decorated porphyrin-based metal-organic frameworks on polydopamine (PD) functionalized Fe3O4 nanospheres for highly efficient enrichment of cis-diol containing nucleosides by magnetic solid phase extraction (MSPE). PD as a molecular linker promotes the nucleation and crystal growth of boronic acid-decorated porphyrin-based metal-organic framework (BA-Zr-MOF), which was synthesized via a dual-ligand strategy by using Zr4+ as a metal unit as well as meso-tetra (4-carboxylphenyl) porphyrin (TCPP) and 1, 4-phenylenebisboronic acid (BA) as dual organic ligands. It is worth noting that the nitrogen-rich skeleton of TCPP and abundant boric acid groups in MOF allows for effective and selective enrichment of cis-diol containing compounds by hydrophilic interaction and boron affinity. Also, Zr4+ well assembled into the MOF is beneficial to extraction via metal oxide affinity interaction due to reversible covalent complex formation/dissociation between Zr and cis-diol compounds. The morphology, structure and saturation magnetization of Fe3O4@PD@BA-Zr-MOF were systematically characterized. The as-prepared adsorbent coupled with high performance liquid chromatography was used for analysis of four nucleosides including cytidine, uridine, guanosine, and adenosine in urine sample with the detection limits in range of 0.002-0.005 µg mL-1 and the quantitative limits in range of 0.008-0.018 µg mL-1. The as-fabricated Fe3O4@PD@BA-Zr-MOF nanospheres shows high selectivity, low detection limit, excellent reusability and reproducibility for nucleosides enrichment. The large specific surface area and quick magnetic response performance endow the affinity magnetic nanospheres with outstanding enrichment capability for rapid extraction. The adsorbent of Fe3O4@PD@BA-Zr-MOF nanospheres has great potential for identification and analysis of trace cis-diol containing nucleosides in biological samples.