A facile chemiluminescence sensing for ultrasensitive detection of heparin using charge effect of positively-charged AuNPs

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Electrospun PCL/collagen hybrid nanofibrous tubular graft based on post-network bond processing for vascular substitute

Inhibiting thrombus formation and intimal hyperplasia is essential for orthotopic tissue-engineered vascular grafts. The matching mechanical properties of autologous blood vessels and inhibition of platelet aggregation are considered as two points to improve the success rate of transplantation. The poly(ε-caprolactone)/collagen/heparin composite vascular graft (PCLHC) with three-dimensional network structure were constructed by electrospinning, which can mimic natural vascular biomechanics and enhance the viability of cells viability in vitro. The hybrid collagen matrix network nanofibers formed by electrospinning exhibited uniform and smooth morphology. The results of mechanical experiments showed that PCLHC had similar mechanical properties to natural blood vessels. And the addition of heparin enhanced the anticoagulation of PCLHC. Simultaneous three-component hybrid nanofibers showed a potentially reliable ability to promote the proliferation of human umbilical vein endothelial cells (HUVECs). In summary, all the results showed that the three-dimensional network structure of PCLHC presented the potential to heal injured vessels.

Analysis of the Glycosaminoglycan Chains of Proteoglycans

Glycosaminoglycans (GAGs) are heterogeneous, negatively charged, macromolecules that are found in animal tissues. Based on the form of component sugar, GAGs have been categorized into four different families: heparin/heparan sulfate, chondroitin/dermatan sulfate, keratan sulfate, and hyaluronan. GAGs engage in biological pathway regulation through their interaction with protein ligands. Detailed structural information on GAG chains is required to further understanding of GAG-ligand interactions. However, polysaccharide sequencing has lagged behind protein and DNA sequencing due to the non-template-driven biosynthesis of glycans. In this review, we summarize recent progress in the analysis of GAG chains, specifically focusing on techniques related to mass spectroscopy (MS), including separation techniques coupled to MS, tandem MS, and bioinformatics software for MS spectrum interpretation. Progress in the use of other structural analysis tools, such as nuclear magnetic resonance (NMR) and hyphenated techniques, is included to provide a comprehensive perspective.

Nanomaterial-enhanced chemiluminescence reactions and their applications

Chemiluminescence (CL) analysis is a trace analytical method that possesses advantages including high sensitivity, wide linear range, easy operation, and simple instruments. With the development of nanotechnology, many nanomaterial (NM)-enhanced CL systems have been established in recent years and applied for the CL detection of metal ions, anions, small molecules, tumor markers, sequence-specific DNA, and RNA. This review summarizes the research progress of the nanomaterial-enhanced CL systems the past five years. These CL reactions include luminol, peroxyoxalate, lucigenin, ultraweak CL reactions, and so on. The CL mechanisms of the nanomaterial-enhanced CL systems are discussed in the first section. Nanomaterials take part in the CL reactions as the catalyst, CL emitter, energy acceptor, and reductant. Their applications are summarized in the second section. Finally, the challenges and opportunities are discussed.

Highly sensitive and simple colorimetric assay of hydrogen peroxide and glucose in human serum via the smart synergistic catalytic mechanism

Due to the own defects of natural enzymes, artificial simulated enzymes are always concerned. Here, the fabricated graphene oxide (GO)/AuNPs nanocomposite exhibits strong synergistic catalysis of peroxidase-mimicking enzymes in combination with the novel property of GO catalytic interface and AuNPs-mediated electron transfer. It can efficiently catalyze the oxidation of enzyme substrate TMB by hydrogen peroxide to form blue TMB oxide. Based on this, the rapid and highly sensitive colorimetric detection of hydrogen peroxide was achieved. Because of the wonderfully synergistic coupling catalysis from GO/AuNPs nanocomposites, the developed artificial enzyme has ultra-strong catalytic activity. For the detection of hydrogen peroxide, the detection limit of this colorimetric analysis is as low as 4.2 × 10^-8 M, which is about 1-2 orders of magnitude lower than that of the assays using other single nanoparticles as nanozymes. And it shows high sensitivity. The catalytic oxidation of the prepared nanocomposites to TMB can be completed in minutes, and the response is extremely fast. Combined with the reaction of glucose and glucose oxidase, the colorimetric analysis also realizes the rapid and highly sensitive detection of glucose in human serum. The research results infer that the smart synergy is an effective way to improve the catalytic activity of mimic enzyme. Together with its simplicity in preparation, the GO/AuNPs nanocomposite has excellent development potential in biomedical detection and biosensor design.

Lost in (Clinical) Translation: Recent Advances in Heparin Neutralization and Monitoring

The heparin family, which includes unfractionated heparin, low-molecular heparin, and fondaparinux, is a class of drugs clinically used as intravenous blood thinners. To date, issues related to both the reversal of anticoagulation and the blood level determination of the anticoagulant at the point-of-care remain: while the only U.S. Food and Drug Administration (FDA) approved antidote for heparin displays serious efficacy and safety drawbacks, the current assays for heparin monitoring are indirect measurements subject to their own limitations and variations. Herein, we provide an update on the numerous recent chemical approaches to tackle these issues, from which it is clear that some new antidotes and sensors for heparin certainly have the potential to exceed current clinical standards. This review aims to review a field that requires close collaborations between physicians, biologists, and chemists in order to foster advances toward clinical translation.

A novel management strategy for removal and degradation of polybrominated diphenyl ethers (PBDEs) in waste printed circuit boards

Waste printed circuit boards (PCBs) contain a high level of brominated flame retardants (BFRs), among which polybrominated biphenyl ethers (PBDEs) are the most widely used additive BFRs. PBDEs are considered to be a type of persistent organic pollutants (POPs). The efficient removal/degradation of PBDEs in waste PCBs is an urgent problem in electronic waste treatment, but the degradation of PBDEs is a great challenge due to their extreme stability and persistence in nature. In this study, a novel management strategy was developed for removal and degradation of PBDEs in waste PCBs by using a simple subcritical methanol (SubCM) process. The results showed that reaction temperature, residence time, solid-to-liquid ratio, and additive NaOH are key factors influencing the removal of PBDEs from waste PCBs. Under optimal conditions (200 °C, 60 min, 1:20 g/mL), the removal efficiency of ∑₈PBDEs from waste PCBs could reach 91.3% and 98.8% for the proposed process of SubCM and SubCM + NaOH, respectively. When the temperature is below 200 °C, highly brominated PBDEs congeners in waste PCBs were degraded into 2,'3,4',6-Tetrabromodiphenyl ether (BDE71) and 2,4,4'-Tribromodiphenyl ether (BDE28) after SubCM treatment. 4-Bromophenyl ether (BDE4) and diphenyl ether were generated by the further debromination of BDE71 and BDE28 with the increase of treatment temperature. The debromination temperature of PBDEs congeners in SubCM could be markedly lowered by adding 4 g/L of NaOH. The complete debromination of PBDEs congeners in waste PCBs could be achieved at 300 °C and 250 °C for the developed process of SubCM and SubCM + NaOH, respectively.

Practical aptamer-based assay of heavy metal mercury ion in contaminated environmental samples: convenience and sensitivity

Due to heavy metals' magnified pollution from their accumulation in the ecosystem, practical detection of ultra-low concentration of heavy metals in environmental sample is of great significance for environmental supervision and maintenance of people's health. Herein, a practical and sensitive assay of heavy metal mercury was developed by visually observing (or spectrum detecting) the change of cationic gold nanoparticles (AuNPs), which is directly caused by mercury ion induced hybridization between non-canonical base pairs. In this assay, signal probe's response was direct rather than the indirect salt induction, thus avoiding the defect of salt-induced indirect response. It makes the analysis more sensitive. The results showed that the response of 8.2 × 10^-8 M Hg²⁺ could be observed with naked eye and the detection limit of Hg²⁺ in spectrometric determination was 4.9 × 10^-11 M, which is more than one order of magnitude lower than that from indirect response pattern of signal probe. In addition, high specificity of the affinity chemistry for T-Hg-T renders the assay to be highly selective. Compared with the results of cold vapor atom adsorption spectroscopy (CVAAS), this analysis has good reliability for the detection of mercury. The results fully indicate that the developed assay is an ideal alternative for online detection of heavy metal mercury in environmental pollution samples.