187147-07-5Relevant academic research and scientific papers
Tobramycin-loaded complexes to prevent and disrupt Pseudomonas aeruginosa biofilms
Avancini, Greta,Bellato, Federica,Boffoli, Delia,Cámara, Miguel,Caliceti, Paolo,Gurnani, Pratik,Mantovani, Giuseppe,Mastrotto, Francesca,Moret, Francesca,Robertson, Shaun,Romero, Manuel,Salmaso, Stefano,Sandrelli, Federica,Yilmaz, Gokhan
, (2021/12/01)
Carbohydrate-based materials are increasingly investigated for a range of applications spanning from healthcare to advanced functional materials. Synthetic glycopolymers are particularly attractive as they possess low toxicity and immunogenicity and can be used as multivalent ligands to target sugar-binding proteins (lectins). Here, we utilised RAFT polymerisation to synthesize two families of novel diblock copolymers consisting of a glycopolymers block containing either mannopyranose or galactopyranose pendant units, which was elongated with sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS) to generate a polyanionic block. The latter enabled complexation of cationic aminoglycoside antibiotic tobramycin through electrostatic interactions (loading efficiency in the 0.5–6.3 wt% range, depending on the copolymer). The resulting drug vectors were characterized by dynamic light scattering, zeta-potential, and transmission electron microscopy. Tobramycin-loaded complexes were tested for their ability to prevent clustering or disrupt biofilm of the Pseudomonas aeruginosa Gram-negative bacterium responsible for a large proportion of nosocomial infection, especially in immunocompromised patients. P. aeruginosa possesses two specific tetrameric carbohydrate-binding adhesins, LecA (PA-IL, galactose/N-acetyl-D-galactosamine-binding) and LecB (PA-IIL, fucose/mannose-binding), and the cell-associated and extracellular adhesin CdrA (Psl/mannose-binding) thus ideally suited for targeted drug delivery using sugar-decorated tobramycin-loaded complexes here developed. Both aliphatic and aromatic linkers were utilised to link the sugar pendant units to the polyacrylamide polymer backbone to assess the effect of the nature of such linkers on bactericidal/bacteriostatic properties of the complexes. Results showed that tobramycin-loaded complexes efficiently suppressed (40 to 60% of inhibition) in vitro biofilm formation in PAO1-L P. aeruginosa and that preferential targeting of PAO1-L biofilm can be achieved using mannosylated glycopolymer-b-AMPSm. Graphical abstract: [Figure not available: see fulltext.].
Control of protein-binding kinetics on synthetic polymer nanoparticles by tuning flexibility and inducing conformation changes of polymer chains
Hoshino, Yu,Nakamoto, Masahiko,Miura, Yoshiko
, p. 15209 - 15212 (2012/11/13)
Although a number of procedures to create synthetic polymer nanoparticles (NPs) with an intrinsic affinity to target biomacromolecules have been published, little has been reported on strategies to control the binding kinetics of target recognition. Here,
Cross-linked surface-grafted glycopolymer for multivalent recognition of lectin
Yu, Lei,Huang, Mingchuan,Wang, Peng G.,Zeng, Xiangqun
, p. 8979 - 8986 (2008/03/14)
An α-link mannose-conjugated acrylamide monomer was synthesized. This monomer was polymerized by free radical polymerization with acrylamide, a cross-linker, and a surface linker directly on the gold surface. The surface linker, with an active carbon-carbon double bond, was preimmobilized on the gold surface by the thiol anchor. Thus, a cross-linked mannose-conjugated polymer thin layer was grafted onto a gold surface. This thin layer of polymer showed high binding sensitivity and excellent selectivity to its target lectin, concanavalin A (Con A), surpassing the formerly used linear glycopolymer and self-assembled glycol monolayers, validated by the techniques of quartz crystal microbalance, atomic force microscopy, and surface plasmon resonance. Remarkable response was observed to Con A at a concentration as low as 5 × 10 -10 M. The response is proportional to the Con A concentration up to 10-7 M in phosphate-buffered saline. The use of cross-linked polymer decreased the flexibility of the polymer backbone between the carbohydrate binding sites. Therefore, the cost of conformational entropy for multivalent binding was minimized. The binding constants of the so-prepared cross-linked polymer with Con A were measured to be between 2.5 × 106 and 3.2 × 106 M-1. These values are significantly larger than that obtained in our early study with a carbohydrate self-assembled monolayer. In addition to the carbohydrate-lectin recognition, additional selectivity may be achieved by controlling the degree of cross-linking.
Macromolecular recognition: Effect of multivalency in the inhibition of binding of yeast mannan to concanavalin A and pea lectins by mannosylated dendrimers
Page, Daniel,Zanini, Diana,Roy, Rene
, p. 1949 - 1961 (2007/10/03)
The synthesis and binding properties of a new family of high affinity α-D-mannopyranoside ligands are described. The synthesis of the new multivalent ligands is based on the scaffolding of multiantennary branches of L-lysine residues having electrophilic N-chloroacetylated end groups as core structures. An α-D-mannopyranoside with p-substituted aryl aglycon ending with a thiol group was prepared and covalently attached to each of the branches of the dendritic structures. The resulting glycodendrimers with 2 (12), 4 (14), 8 (16), and 16 (18) mannoside residues were tested for their relative inhibitory potency by solid-phase enzyme-linked lectin assays (ELLA) using methyl and p-nitrophenyl α-D-mannopyranosides as standards. Concentrations necessary for 50% inhibition (IC50s) of binding of yeast mannan to Jack bean phytohemagglutinin (Canavalia ensiformis, concanavalin A) and to pea lectin (Pisum sativum) were determined. Analogous mannosylated copolyacrylamides were also prepared for comparison. The IC50 values were also plotted as a function of dendrimer valencies. The inhibitions showed 16-mer 18 to be approximately 600- and 2000-fold more potent than methyl α-D-mannopyranoside, and 66- and 1383-fold more potent than p-nitrophenyl α-D-mannopyranosides with Con A and pea lectins, respectively. Even when these numbers are expressed relative to single mannopyranoside residues per dendrimers, the relative potencies against the aromatic mannoside are still 4- and 86-fold better against Con A and pea lectins. These results unequivocally indicate that the optimum inhibitory binding properties of the new mannosylated dendrimers vary with both dendrimer and lectin valencies.
