Preparation of macroporous rigid agarose microspheres by pre-crosslinking with cyclic anhydride.

In this study, a new method for preparing macroporous rigid agarose microspheres was developed by one-step pre-crosslinking method with cyclic anhydride. Three different cyclic anhydrides, namely, maleic anhydride, succinic anhydride, and glutaric anhydride, were used to pre-crosslink agarose. The reaction temperature and the amount of cyclic anhydride in the pre-crosslinking process were optimized to endow agarose with stronger cross-linking. Under the optimal cross-linking condition, macroporous rigid agarose microspheres with homogeneous particle size were successfully obtained by adjusting emulsification method. Cryo-scanning electron microscopy was used to characterize the morphology of cross-linked agarose gel and microspheres. The addition of cyclic anhydride increased the gel aperture of cross-linked agarose microspheres, thereby making the macropores in the microspheres more dense and enhancing the mass transfer in the particles. Under low pressure, the cross-linked agarose microsphere column can effectively separate model proteins at linear flow rates three times higher than the agarose microsphere column. These results indicate that the developed agarose microspheres are a promising high-speed chromatographic medium.