Niosomes Functionalized with a Synthetic Carbohydrate Binding Agent for Mannose-Targeted Doxorubicin Delivery

Biomimetic Recognition of SARS-CoV-2 Receptor-Binding Domain N-Glycans by an Antiviral Synthetic Receptor

Recognition of glycans by simple synthetic receptors is a key issue in supramolecular chemistry, endowed with relevant implications in glycobiology and medicine. In this context, glycoproteins featuring N-glycans represent an important biological target, because they are often exploited by enveloped viruses in adhesion and infection processes. However, a direct evidence for their recognition by a synthetic receptor targeting N-glycans is still missing in the literature. Using a combination of glycoengineering and mass spectrometry techniques, we present here the direct evidence of biomimetic recognition of complex-type N-glycans exposed on the receptor-binding domain (RBD) of the wild-type spike protein of SARS-CoV-2 by a biologically active, synthetic receptor.

Synthetic molecular cage receptors for carbohydrate recognition

A captivating challenge in chemistry lies in achieving robust and precise binding of uncharged, hydrophilic carbohydrate entities. Although past decades have provided a variety of excellent molecular architectures tailored for carbohydrate recognition, including acyclic receptors, macrocycles and foldamers, recent advances have highlighted the potential of synthetic molecular cages. These structures are equipped with intricately designed cavities that contain bespoke noncovalent binding sites for carbohydrate interactions. Constructed with the principles of complementarity and preorganization, these cage receptors demonstrate high affinity and exquisite selectivity in carbohydrate recognition through noncovalent interactions, capitalizing on multivalency and cooperativity. This Review highlights recent advances in the design and application of molecular cages with diverse structures, interactions and binding capacities for carbohydrate recognition. In the concluding remarks, we discuss future avenues for further exploration.

Towards Biomimetic Recognition of Glycans by Synthetic Receptors

Carbohydrates are abundant in Nature, where they are mostly assembled within glycans as free polysaccharides or conjugated to a variety of biological molecules such as proteins and lipids. Glycans exert several functions, including protein folding, stability, solubility, resistance to proteolysis, intracellular traffic, antigenicity, and recognition by carbohydrate-binding proteins. Interestingly, misregulation of their biosynthesis that leads to changes in glycan structures is frequently recognized as a mark of a disease state. Because of glycan ubiquity, carbohydrate binding agents (CBAs) targeting glycans can lead to a deeper understanding of their function and to the development of new diagnostic and prognostic strategies. Synthetic receptors selectively recognizing specific carbohydrates of biological interest have been developed over the past three decades. In addition to the success obtained in the effective recognition of monosaccharides, synthetic receptors recognizing more complex guests have also been developed, including di- and oligosaccharide fragments of glycans, shedding light on the structural and functional requirements necessary for an effective receptor. In this review, the most relevant achievements in molecular recognition of glycans and their fragments will be summarized, highlighting potentials and future perspectives of glycan-targeting synthetic receptors.

Surface entrenched β-sitosterol niosomes for enhanced cardioprotective activity against isoproterenol induced cardiotoxicity in rats

Cardiotoxicity (CT) is a severe condition that negatively impacts heart function. β-sitosterol (BS) is a group of phytosterols and known for various pharmacological benefits, such as managing diabetes, cardiac protection, and neuroprotection. This study aims to develop niosomes (NS) containing BS, utilizing cholesterol as the lipid and Tween 80 as the stabilizer. The research focuses on designing and evaluating both conventional BS-NS and hyaluronic acid (HA) modified NS (BS-HA-NS) to enhance the specificity and efficacy of BS within cardiac tissue. The resulting niosomal formulation was spherical, with a size of about 158.51 ± 0.57 nm, an entrapment efficiency of 93.56 ± 1.48 %, and a drug loading of 8.07 ± 1.62 %. To evaluate cytotoxicity on H9c2 heart cells, the MTT assay was used. The cellular uptake of BS-NS and BS-HA-NS was confirmed by confocal microscopy on H9c2 cardiac cells. Administering BS-NS and BS-HA-NS intravenously at a dose of 10 mg/kg showed the ability to significantly decrease the levels of cardiac troponin-I (cTn-I), creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and lipid peroxidation (MDA). Tissue histopathology indicated a substantial potential for repairing cardiac tissue after treatment with BS-NS and BS-HA-NS and strong cardioprotection against ISO induced myocardial tissue damages. Thus, enhancing BS's therapeutic effectiveness through niosome surface modification holds promise for mitigating cardiac damage resulting from CT.

Biological function, regulatory mechanism, and clinical application of mannose in cancer

Studies examining the regulatory roles and clinical applications of monosaccharides other than glucose in cancer have been neglected. Mannose, a common type of monosaccharide found in human body fluids and tissues, primarily functions in protein glycosylation rather than carbohydrate metabolism. Recent research has demonstrated direct anticancer effects of mannose in vitro and in vivo. Simply supplementing cell culture medium or drinking water with mannose achieved these effects. Moreover, mannose enhances the effectiveness of current cancer treatments including chemotherapy, radiotherapy, targeted therapy, and immune therapy. Besides the advancements in basic research on the anticancer effects of mannose, recent studies have reported its application as a biomarker for cancer or in the delivery of anticancer drugs using mannose-modified drug delivery systems. This review discusses the progress made in understanding the regulatory roles of mannose in cancer progression, the mechanisms underlying its anticancer effects, and its current application in cancer diagnosis and treatment.