Morphology-controlled Dual Clickable Nanoparticles Via Ultrasonic-assisted Click Polymerization For Biological Applications

Advantages of polymeric nanoparticles(PNPs), including low cytotoxicity, biocompatibility, and functional diversity, have led to numerous applications in fabrication of nanomedicine, cell imaging, bioanalysis, polymer therapy and other biological areas. Due to the great influence of morphology on the properties and behaviors of polymer nanoparticles, morphology control has become a key point in the area. In this work, we demonstrate a novel approach for morphology-controlled fabrication of dual clickable nanoparticles(DCNPs) based on ultrasonic-assisted azide-alkyne click polymerization. In addition, glyconanoparticles(GNPs) and fluorescent glyconanoparticles(FGNPs) were easily synthesized via click reaction by using DCNPS as a platform, and further applied to carbohydrate-protein interaction and cell imaging, respectively.Dual clickable nanospheres(DCNSs) were synthesized in one step using an efficient approach of ultrasonic-assisted azide-alkyne click polymerization, avoiding the need of surfactants. This novel approach presents a direct clickable monomer-to-nanosphere synthesis. Firstly, we investigated the effect of monomer structure, solvent, catalyst, ultrasonic frequency and power on the morphology of the polymers and optimized the experimental conditions. The results indicated that the nanospheres with narrow distribution could be obtained in CH3CN/CHCl3(96:4, v/v) solvent mixture and the nanorods in CHCl3 under the ultrasonic irradiation, respectively. Secondly, the mechanism of the formation of the nanorods was studied. It was found that the coordination of copper ions with the pyridine rings and triazoles under the specific untrasonic and solvent were critical to form the rod-like structure. Finally, The amount of residual function groups on the surface of DCNPs were determined by HPLC with azide groups 38 μmol g-1 polymer and alkynyl groups 15 μmol g-1 polymer, respectively. The numerous terminal alkynyl and azide groups on the surface of DCNPs facilitate effective conjugation of multiple molecules or ligands onto a single nanocarrier platform under mild conditions.To exemplify the potential of DCNSs in biological applications, 1) multivalent glyconanoparticles(GNPs) were prepared by clicking with azide-functionalized and alkyne-functionalized lactose sequentially for determining carbohydrate-galectin interactions via quartz crystal microbalance(QCM) biosensor. The QCM sensorgrams showed excellent binding activity of GNPs for galectins by using a protein chip(purified galectin-3 coated on chip) or a cell chip(Jurkat cells immobilized on chip); 2) fluorescent GNPs were prepared by clicking with azide-functionalized Rhodamine B and alkyne-functionalized lactose sequentially for targeting galectins, which are overexpressed on the surface of Jurkat cells. The fluorescent images obtained clearly showed the cellular internalization of fluorescent GNPs. This fluorescent probe could be easily adapted to drugs for constructing lectin-targeted drug delivery systems. Thus, DCNSs prepared with our method may provide a wide range of potential applications in glycobiology and biomedicine.