Electrically controlled release of macromolecules from cross-linked hyaluronic acid hydrogels

Stimuli-responsive nanomaterials for therapeutic protein delivery

“…Relevant electro-responsive hydrogels have long been studied. Back in 1995, Florence et al reported the electro-responsive behavior of crosslinked hyaluronic acid (HA) [108]. HA is a naturally existing polysaccharide distributed widely throughout connective, epithelial, and neural tissues, which plays a central role in regulating cell growth and renewal.…”

Rapid and Extensive Collapse from Electrically Responsive Macroporous Hydrogels

“…The time required for water and ion diffusion can be reduced by simply scaling down the size of the hydrogels, [6] but this does not directly address the need to facilitate transport. Larger electrically responsive hydrogels have been limited to response times of 30 minutes [7] , to hours [8,9,10] , or tens of hours [5] .…”

“…AAc- co -AAm gels with a reported 20% charge along the polymer (0.0028 e Da −1 ) were capable of extensive collapse (500-fold) but collapsed very slowly, likely due to their nanoporosity. [5] Relatively high temporal responsivities were reported (60% collapse in 30 minutes) when using nanoporous hyaluronic acid (HA) gels [7] (0.0026 e Da −1 ). It has been shown previously that varying the polymer charge density alters responsivity, though responsivity was measured in terms of drug delivery and not explicitly by volumetric collapse.…”

Bioinspired Design of Dynamic Materials

“…Examples include pH-responsive, [6,7] temperatureresponsive, [8][9][10] electroresponsive, [11][12][13][14] and photoresponsive hydrogels. [15,16] pH-responsive and temperature-responsive hydrogels have been particularly prevalent in the biomaterials science literature, with initial examples extending back to the 1980s.…”