A temperature-sensitive DNA-PNIPAAm hydrogel prepared by base pairing

In this paper, a DNA-PNIPAAm (poly-N-isopropyl acrylamide) has been synthesized by PNIPAAm and multi-acryloyl–modified Y-type DNA. Interpenetrated networks (IPN) were synthesized through base pairing of three single DNA and cross-linking of NIPAAm with multi-acryloyl–modified Y-type DNA as a cross-linking agent. The mechanical strength, phase transformation temperatures (DSC), and cloud point of the DNA-PNIPAAm hydrogel have been tested. The results of DSC and cloud point analysis show that the introduction of DNA increases the response temperature of PNIPAAm, making it closer to the temperature of human body. In addition, due to the introduction of multi-acryloyl groups in the DNA, the reaction efficiency of DNA and NIPAAm was improved, and the concentration of DNA was just 0.9% times of that used in prior studies. This is a new method to prepare DNA and polymer composite hydrogel using low DNA concentration, and a new DNA-PNIPAAm hydrogel material has been prepared.