A series of carbosilane dendrimers uniformly functionalized with hemagglutinin (HA) binding peptide (sialic acid-mimic peptide, Ala-Arg-Leu-Pro-Arg) was systematically synthesized, and their anti-influenza virus activity was evaluated. The carbosilane-based peptide dendrimers, unlike sialylated dendrimers, cannot be digested by virus neuraminidases. The peptide dendrimers exhibited intriguing biological activities depending on the form of their core frame, with a dumbbell-type peptide dendrimer showing particularly strong inhibitory activities against two human influenza viruses, A/PR/8/34 (H1N1) and A/Aichi/2/68 (H3N2). The IC50 values of the dumbbell-type peptide dendrimer for both strains were 0.60 μM, the highest activity among the HA-binding peptide derivatives. The results suggest that a dumbbell-shaped carbosilane dendrimer is the most suitable core scaffold for HA-binding peptide dendrimers.

Glycodendrimers fascinate both carbohydrate chemists and biologists because of their ability to recognize lectins and enhance carbohydrate–protein interactions. These characteristics make glycodendrimers a valuable tool in glycoscience and chemical biology. Many glycodendrimers have been described to date; this tutorial review focuses specifically on carbosilane glycodendrimers. We present methodologies for synthesizing parent carbosilane dendrimers and describe their use in biological assays. We also describe representative functionalizations of parent carbosilane dendrimers at terminal positions which are necessary for chemical ligation with carbohydrate ligands. This is followed by a description of all coupling reactions between carbohydrate and carbosilane dendrimer functionalities used in the synthesis of carbosilane glycodendrimers. The major emphasis of this review is the use of carbosilane glycodendrimers as medical agents against Shiga toxins, dengue viruses, relapsing fever Borrelia, and hemagglutinin and neuraminidase of influenza viruses, as well as on the relationship between dendrimer structure and these biological activities. The last two sections introduce recent attempts to use carbosilane glycodendrimers as new versatile and widely-applicable lectin sensors, and the use of carbosilane glycodendrimers as a novel drug carrier in an active targeting drug delivery system. This review article will be of interest to scientists in the areas of organic chemistry, chemical biology, carbohydrate chemistry, heteroatom chemistry, and organosilicon chemistry.

A carbosilane dendrimer (4a) and its silacyclopentadiene analog (4b), both functionalized with lactoses, were tested for their abilities to act as drug-delivery systems. The critical micelle concentrations of 4a and 4b were measured using the drop-volume method in water and were 1.7 and 2.9 μM, respectively, suggesting that they could act as aggregates of glycoclusters. The amounts of the hydrophobic dye Orange OT loaded onto aqueous micelles of 4a and 4b and the stabilities of the dye/micelle complexes were determined by extracting the dyes from the complexes into chloroform. The particle sizes were measured for the loaded micelles by dynamic light scattering. Transfer of the dye from the micelles to peanut agglutinin was observed by fluorescence microscopy. Given the abilities of micelles of 4a and 4b to bind and release Orange OT, these glycocluster micelles may find use as drug-delivery systems.

Glycodendrimers fascinate both carbohydrate chemists and biologists because of their ability to recognize lectins and enhance carbohydrate–protein interactions. These characteristics make glycodendrimers a valuable tool in glycoscience and chemical biology. Many glycodendrimers have been described to date; this tutorial review focuses specifically on carbosilane glycodendrimers. We present methodologies for synthesizing parent carbosilane dendrimers and describe their use in biological assays. We also describe representative functionalizations of parent carbosilane dendrimers at terminal positions which are necessary for chemical ligation with carbohydrate ligands. This is followed by a description of all coupling reactions between carbohydrate and carbosilane dendrimer functionalities used in the synthesis of carbosilane glycodendrimers. The major emphasis of this review is the use of carbosilane glycodendrimers as medical agents against Shiga toxins, dengue viruses, relapsing fever Borrelia, and hemagglutinin and neuraminidase of influenza viruses, as well as on the relationship between dendrimer structure and these biological activities. The last two sections introduce recent attempts to use carbosilane glycodendrimers as new versatile and widely-applicable lectin sensors, and the use of carbosilane glycodendrimers as a novel drug carrier in an active targeting drug delivery system. This review article will be of interest to scientists in the areas of organic chemistry, chemical biology, carbohydrate chemistry, heteroatom chemistry, and organosilicon chemistry.