Mannosylated fluorescent cellulose‐based glycopolymers for stable uniform nanoparticles

Abstract

Abstract In living organisms, carbohydrate‐protein interactions play key roles in physiological and pathological processes, which are amplified by the “glycol‐cluster effect.” In this work, we synthesized novel fluorescent cellulose derivatives bearing mannose moieties via thiol‐ene click reactions by sequentially conjugating hydrophilic mannose‐oxyethoxylpropane‐thiol (Mann‐SH) and fluorescent coumarin‐oxyhexyl‐thiol (Coum‐SH) and rhodamine B‐ethyl‐thiol (RhB‐SH) to cellulose undecenoate with terminal double bonds. The amphiphilic fluorescent cellulose derivatives were converted into nanoparticles (NPs) by dropping into low ionic strength solutions (\u0026lt;0.085 M). Obtained NPs have average sizes between 240 and 554 nm depending on the solution concentrations, exhibiting uniform size distributions (PDI values \u0026lt;0.12). These uniform NPs exhibited excellent dispersion stability even at elevated temperatures. The mannose moieties were accessible to 1,4‐benzenediboronic acid (BDBA) in NaOH aqueous solutions. Under irradiation with UV light of 320–400 nm, the fluorescence of NPs increased by the formation of open‐ring rhodamine spiroamide, which could be a promising candidate for biomedical application.

A novel fluorescent cellulose derivative bearing mannose, coumarin, and rhodamine moieties is synthesized via two‐step photo‐/thermo‐initiated thiol‐ene click reactions, and stable uniform nanoparticles (NPs) are formed. The mannose moieties of NPs are accessible to 1,4‐benzenediboronic acid (BDBA) in NaOH solutions, and NPs are stabilized in strong alkaline solutions at elevated temperatures. The fluorescence intensity of NPs is increased under irradiation with UV light of 320–400 nm, which allows them to be promising candidates for biomedical applications. image