Poly (N-isopropylacrylamide-co-N-acryloxysuccinimide) [poly(NIPAAm-co-NAS)] grafted silica was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). Heparin was immobilized onto the silica surface through the reaction between NAS and the amino group of heparin. The ratio of the copolymer on silica was quantitativel determined using thermogravimetric analysis. To determine whether the grafted copolymer had critical soluble /insoluble changes in response to emperature, we performed optical transmittance measurements. Enhanced thermosensitivity was demonstrated by the significant changes of steroids in retention time under thermal stimulus. The prepared silica was then employed for the separation and enrichment of thrombin via a thermally-modulated capture and release process instead of changing the composition of mobile phase. The results indicated the strong affinity interaction between thrombin and the heparin affinity column at 10 �C,and increasing the temperature to 50 �C can induce the release of the thrombin. This is an easier and more practical approach compared to the conventional need to change the pH of the mobile phase.

Switchable heparin affinity materials for thermally-modulated capture, release, and enrichment of thrombin

245th National Meeting (2013)

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