Synthesis and characterization of radio-opaque thermosensitive poly N-isopropylacrylamide-2,2′-(ethylenedioxy)bis (ethylamine)-2,3,5-triiodobenzamide

Background: In situ gelling polymers, like poly(N-isopropylacrylamide) (poly(NIPAAm)), have many potential medical applications due to their biocompatibility and thermosensitivity. Results: Radio-opaque thermosensitive poly(NIPAAm) grafted with 10.7 wt% 2,2′-(ethylenedioxy)bis(ethylamine)-2,3,5- triiodobenzamide was successfully synthesized and characterized. The conjugated polymer showed good visibility with X-ray fluoroscopy. The polymer had a lower critical solution temperature of 30 °C after conjugation with triiodobenzamide as determined by cloud point determination and a transition peak temperature of 33.3 ± 0.57 °C as determined by differential scanning calorimetry. Conclusion: The polymer synthesized was highly visible under X-rays, based upon the percentage incorporation of triiodobenzamide. After conjugation of the NIPAAm to the triiodobenzamide through a bis(ethylamine) linkage, the resultant polymer retained lower critical solution temperature characteristics in a temperature region that makes it physiologically useful.