Polymers sensitive to the bodys external stimuli

Switchable and Responsive Surfaces and Materials for Biomedical Applications 

These results indicated that temperature-sensitive polymers can control interaction between nanoparticular drug delivery systems and the cellular surface, as the pNIPAM are used in cell culture dishes for cell sheet engineering (Yang et al., 2006). 

Ag-Au bimetallic nanopartide f Thermo-responsive nonlinear PEG-based hydrogel — Hyaluronic acid 

Microbubbles having a shell of poly(acrylic acid) and phospholipids have been reported as another ultrasound-sensitive system (Du et al., 2011). Poly(acrylic acid) had no interaction with liposomes at neutral pH, but bound to the surface of liposomes at acidic pH below its of 4.5. From these results, design of suitable polymers and control of interaction between the particles and cellular surface are expected to advance the ultrasound-sensitive drug delivery systems. 

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