Aggregation of biotinylated polymeric microspheres induced by interaction with avidin*
Qingbin Meng1, Zhanyong Li1, Gang Li1, Xu Zhang1, Yingli An1, and X. X. Zhu1,2
1Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, Nankai University, Tianjin, 300071, China; 2Department of Chemistry, University of Montréal, C.P. 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
Abstract: Monodisperse biotinylated poly(styrene-co-N-acryloxysuccinimide) microspheres were synthesized in aqueous solutions with a two-step method. Upon the addition of avidin solutions of different concentrations in phosphate buffer into the dispersed biotinylated microspheres, the microspheres aggregated rapidly due to the high binding affinity between biotin and avidin. The hydrodynamic diameter of the aggregates and the aggregation rate observed at given time intervals increased with increasing concentration of avidin. The composition of the microspheres and the incorporation of biotin were evidenced by Fourier transform infrared spectroscopy. The morphology, size distribution, and aggregation of the microspheres were studied by techniques such as scanning electron microscopy and dynamic light scattering.
Keywords: polymer microspheres; biotinylation; emulsion polymerization; bioconjugation; aggregation.
*Paper based on a presentation at the 12th International Conference on Polymers and Organic Chemistry 2006 (POC'06), 2-7 July 2006, Okazaki, Japan. Other presentations are published in this issue, pp. 1471-1582.