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Cancer presents a significant health threat, necessitating the development of more precise, efficient, and less damaging treatment approaches. To address this challenge, we employed the 1-ethyl-(3-dimethyl aminopropyl) carbodiimide/ N -hydroxy succinimide (EDC/NHS) catalytic system and utilized quaternized chitosan oligosaccharide (HTCOSC) as a drug carrier to construct a nanoparticle delivery system termed HTCOSC-cRGD-ES2-MTX (CREM). This system specifically targets integrin αvβ3 on tumor cell surfaces and enables simultaneous loading of the antiangiogenic agent ES2 (IVRRADRAAVP) and the chemotherapy drug methotrexate (MTX). Due to its amphiphilic properties, CREM self-assembles into nanoparticles in aqueous solution, exhibiting an average diameter of 179.47 nm. Comparative studies demonstrated that CREM, in contrast to free ES2 and MTX-free nanoparticles (CRE), significantly suppressed the proliferation of EAhy926 endothelial cells and B16 melanoma cells in vitro , resulting in inhibition rates of 71.18 and 82.25%, respectively. Furthermore, CREM exhibited a hemolysis rate below 2%, indicating excellent in vitro antiangiogenic and antitumor activity as well as favorable blood compatibility. Additionally, both CRE and CREM demonstrated favorable tumor targeting capabilities through the specific binding action of cyclic RGD (cRGD) to integrin αvβ3. Further in vivo investigations revealed that CREM induced apoptosis in tumor cells via the mitochondrial apoptotic pathway and reduced the expression of angiogenic factors such as vascular endothelial growth factor (VEGF), thereby inhibiting tumor angiogenesis. This potent antitumor effect was evident through a tumor suppression rate of 80.19%. Importantly, histopathological staining (HE staining) demonstrated the absence of significant toxic side effects of CREM on various organs compared to MTX. In conclusion, the CREM nano drug delivery system synergistically enhances the therapeutic efficacy of antiangiogenic drugs and chemotherapeutic agents, thus offering a novel targeted approach for cancer treatment.

In the present study, we studied anti-Alzheimer's disease (AD) activities of chondroitin sulfate (CS) oligosaccharides with different molecular weights. CS from shark cartilage was degraded by a recombinant CS endolyase, chondroitinase ABC I (CHSase ABC I), and CS disaccharide (DP2), tetrasaccharide (DP4), hexasaccharide (DP6), octasaccharide (DP8), decasaccharide (DP10) and dodecasaccharide (DP12) were obtained by separation with gel filtration. Anti-AD activities of CS oligosaccharides were assessed using Aβ-injured SH-SY5Y cells and BV2 cells. It was shown that CS oligosaccharides could block Aβ-induced oxidative stress, mitochondrial dysfunction and activation of intrinsic apoptotic pathway for SH-SY5Y cells. Furthermore, these activities increased with the increase of molecular weights. For Aβ-injured BV2 cells, CS oligosaccharides inhibited oxidative stress, the production of proinflammatory cytokines and the activation of toll-like receptor pathway, and CS DP2 had the best activity among them. In conclusion, CS oligosaccharides suppressed Aβ-induced oxidative stress and relevant injury in vitro, and these effects had different relationships with the molecular weights of CS oligosaccharides for different cell lines, which might be caused by different mechanisms., (© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

An insightful investigation into specificity of bacterial heparinase III has been intriguingly difficult due to heterogeneity of polymeric substrates. Herein, we chemoenzymatically synthesized a tailored library of HS oligosaccharides as substrates. A ∼15-fold reactivity difference to heparinase III was found between trisaccharides bearing different primary cleavage sites. Variable glucosamine modification decreased reactivity of trisaccharides by >20-fold compared with their counterpart primary substrates, while iduronate-containing secondary linkage showed slightly less sensitivity. The 2-sulfated iduronate residue extremely reduced reactivity to its adjacent primary site at reducing end of oligosaccharides, but showed marginal influence on the non-reducing site. Moreover, oligosaccharide susceptibility to digestion was size-dependent and had an obvious preference for the internal linkages over those near to non-reducing/reducing ends. Surface plasmon resonance revealed cleavage promiscuity attributed to different affinities or incorrect binding of substrates to the enzyme. The attractive information on heparinase III will be valuable in characterizing heparin and HS., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The enzymatic synthesis of biologically important and structurally unique human P1PK blood group type P1 pentasaccharide antigen is described. This synthesis features a three-step sequential one-pot multienzyme (OPME) glycosylation for the stepwise enzymatic chain elongation of readily available lactoside acceptor with cheap and commercially available galactose and N-acetylglucosamine as donor precursors. This enzymatic synthesis provides an operationally simple approach to access P1 pentasaccharide and its structurally related Gb3 and P1 trisaccharide epitopes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Uncovering the biological roles of heparosan oligosaccharides requires a simple and robust method for their separation and identification. We reported on systematic investigations of the retention behaviors of synthetic heparosan oligosaccharides on porous graphitic carbon (PGC) column by HPLC with charged aerosol detection. Oligosaccharides were strongly retained by PGC material in water-acetonitrile mobile phase, and eluted by trifluoroacetic acid occurring as narrow peaks. Addition of small fraction of methanol led to better selectivity of PGC to oligosaccharides than acetonitrile modifier alone, presumably, resulting from displacement of methanol to give different chemical environment at the PGC surface. Van't-Hoff plots demonstrated that retention behaviors highly depended on the column temperature and oligosaccharide moieties. By implementing the optimal MeOH content and temperature, a novel isocratic elution method was successfully developed for baseline resolution and identification of seven heparosan oligosaccharides using PGC-HPLC-CAD/MS. This approach allows for rapid analysis of heparosan oligosaccharides from various sources., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Lacto-N-neotetraose and its sialyl and fucosyl derivatives including Lewis x (Le(x)) pentasaccharide, sialyl Lewis x (sLe(x)) hexasaccharide and internally sialylated derivatives were enzymatically synthesized from readily available lactoside, commercially available uridine 5'-diphosphate-glucose (UDP-Glc) and the corresponding monosaccharides using a highly efficient sequential one-pot multienzyme (OPME) strategy. The OPME strategy which combines bacterial glycosyltransferases and sugar nucleotide generation enzymes provides easy access to the biologically important complex oligosaccharides at preparative scale. Moreover, the same OPME strategy can be used for the regioselective introduction of sialic acid to the internal galactose unit of LNnT in a designed glycosylation route by simply changing the glycosylation sequence.

A concise and practical chemoenzymatic synthesis of lacto-N-tetraose, a major component and one of the most common core structures of human milk oligosaccharides (HMOs) was reported. This convergent synthesis relies on the glycosylation of a readily available lactoside acceptor with a lacto-N-biose donor generated from a highly efficient one-pot two-enzyme synthesis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

An expeditious three-component, one-pot sequential glycosylation protocol has been developed for the preparation of 3,6-branched unsymmetrical mannopentaose (Man5), employing a mannose trisaccharide donor, a mannose monosaccharide donor and a mannose monosaccharide acceptor. The high efficiency of this one-pot procedure was demonstrated by comparison study with a stepwise synthesis using the same three building blocks., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A novel chemoenzymatic approach for the synthesis of disialyl tetrasaccharide epitopes found as the terminal oligosaccharides of GD1α, GT1aα, and GQ1bα is described. It relies on chemical manipulation of enzymatically generated trisaccharides as conformationally constrained acceptors for regioselective enzymatic α2-6-sialylation. This strategy provides a new route for easy access to disialyl tetrasaccharide epitopes and their derivatives.

Aims: Oligosaccharides of hyaluronan (o-HAs) were proved to have pro-angiogenic activities. The aim of this study was to obtain four hyaluronan oligosaccharides (o-HAs) of defined molecular weight including 4 saccharide residues (o-HA4), 6 saccharide residues (o-HA6), 8 saccharide residues (o-HA8), and 10 saccharide residues (o-HA10) under optimum conditions, and compare their angiogenic activities., Main Methods: The four o-HAs were prepared by digesting the native high molecular weight HA with hyaluronidase under optimum conditions. The effects of the four o-HAs on human umbilical vein endothelial cell (HUVEC) proliferation were measured using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenil tetrazolium bromide (MTT) assay. Angiogenic effects of the four o-HAs were evaluated using chicken chorioallantoic membrane (CAM) assay. The effects of the four o-HAs on the vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) messenger ribonucleic acid (mRNA) expressions were detected by semi-quantitative polymerase chain reaction (PCR)., Key Findings: O-HA6, o-HA8 and o-HA10 could effectively promote the proliferation of HUVEC, induce angiogenesis in the CAM assay and increase VEGF mRNA levels in HUVEC. No significant effects were found with o-HA4., Significance: These results suggested that o-HA6, o-HA8, and o-HA10, but not o-HA4 were effective angiogenic factors.

As the interaction of hyaluronan (HA) with its receptor CD44 contributes to multidrug resistance (MDR) of tumor cells, HA oligosaccharides (o-HAs), as HA antagonists, may be useful to reverse the MDR. The objective of this study was to investigate the reversal effects of four o-HAs, including 4 saccharide residue (o-HA4), 6 saccharide residue (o-HA6), 8 saccharide residue (o-HA8), and 10 saccharide residue (o-HA10) fragments, on adriamycin (ADR)-resistant K562/A02 cells. The four o-HAs were prepared by digesting the native high molecular weight HA with hyaluronidase and gel filtration chromatography. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to assess the cytotoxicity of the four o-HAs and/or ADR on K562/A02 and K562 cells. The intracellular accumulation of ADR in K562/A02 cells was measured by flow cytometry. By comparing the IC50 (concentration resulting in 50% inhibition of cell growth) of ADR with K562/A02 cells in the presence and absence of a series of different concentrations of o-HAs, the reversal folds of the four o-HAs were calculated. The reversal folds of o-HA4, o-HA6, o-HA8, and o-HA10 were 2.04, 2.05, 1.91, and 1.84, respectively. After o-HA4, o-HA6, o-HA8, and o-HA10 treatment, the intracellular amounts of ADR were increased to 3.90, 3.92, 3.76, and 3.39 times, respectively. Shorter o-HAs (o-HA4 and o-HA6) showed stronger reversal effects than longer o-HAs (o-HA8 and o-HA10). In conclusion, the results showed that the four o-HAs could effectively reverse the ADR resistance of K562/A02 cells by increasing the intracellular accumulation of ADR. O-HAs may be used as MDR reversal drugs to increase the effectiveness of chemotherapy.

Comprehensive Summary: O‐Mannosylation plays a vital role in the regulation of a variety range of biological processes, for instance, brain and muscle development. However, the precise function remains largely unknown due to its innate heterogeneity. In this regard, it is still welcome to develop efficient methods to access diverse structurally‐defined glycopeptides. In this study, a diversity‐oriented assembly of O‐mannosyl α‐dystroglycan (α‐DG) glycopeptides has been achieved via a chemoenzymatic strategy. This strategy features (i) gram scale divergent synthesis of core m1, core m2 and core m3 mannosylated amino acids from judiciously designed protecting group strategies and chemical glycosidation; (ii) efficient glycopeptide assembly via the optimized microwave‐assisted solid phase peptide synthesis (SPPS); and (iii) enzymatic elaboration of the core glycan structures to install galactosyl and sialyl‐galactosyl moieties. The efficiency and flexibility of this chemoenzymatic approach was demonstrated with the construction of 12 glycopeptides with different core m1, core m2 and core m3 mannosyl glycans, including a core m2 glycopeptide bearing a heptasaccharide for the first time. [ABSTRACT FROM AUTHOR]