2019, Folini, Jenny, Huang, Chao-Hung, Anderson, James C., Meier, Wolfgang P., Gaitzsch, Jens

Responsive and biodegradable nanoparticles are essential for functional drug delivery systems. We herein report the first pH sensitive polyester from radical ring-opening polymerisation of novel amine-bearing cyclic ketene acetals (CKAs). The CKAs were synthesised via an intermediate carbonate and the resulting polyesters showed a pKa around pH 6. Together with an initial application in biodegradable nanoparticles, they open the pathway for a new generation of functional polyesters.

2011, Schulz, V., Zschoche, S., Zhang, H.P., Voit, B., Gerlach, G.

Within this work we present the synthesis and characterization of a pH-sensitive macroporous p(AAm-co-AA) hydrogel with an interconnected channel structure to enhance diffusion of aqueous solutions. The hydrogel is characterized by SEM and mercury porosimetry. Furthermore, the hydrogel is successfully integrated into piezoresistive microsensors measuring the hydrogel swelling due to pH changes. A response time reduction of about 80% compared to sensors with conventional non-porous hydrogels is accomplished.