Modulating stiffness in DNA-crosslinked polyacrylamide gels

At Rutgers, we have developed a new class of DNA-crosslinked hydrogels that promise to have a wide range of applications ranging from drug delivery to prosthetics. Advantages of using DNA in place of more common crosslinkers such as bis(acrylamide) include thermoreversibility and the ability to engineer the crosslink length. We have shown previously that gel stiffness is a function of the DNA crosslink density, and demonstrated a second method whereby stiffness was enhanced by generating tensegrity within the gel network. In this study, controlled procedures were employed to monitor the extent to which gel compression during electrophoresis influences the stiffness of the gel. The effects of DNA "fuel" and counter-fuel (removal) strands were investigated. A nearly four-fold increase in elastic modulus was reversibly attained by the introduction of fuel strands to stiffen the crosslinks and create a tensegrity microstructure.