Thermo- and pH-responsive polymers in drug delivery

Adv Drug Deliv Rev. 2006 Dec 30;58(15):1655-70. doi: 10.1016/j.addr.2006.09.020. Epub 2006 Oct 18.


Stimuli-responsive polymers show a sharp change in properties upon a small or modest change in environmental condition, e.g. temperature, light, salt concentration or pH. This behaviour can be utilised for the preparation of so-called 'smart' drug delivery systems, which mimic biological response behaviour to a certain extent. The possible environmental conditions to use for this purpose are limited due to the biomedical setting of drug delivery as application. Different organs, tissues and cellular compartments may have large differences in pH, which makes the pH a suitable stimulus. Therefore the majority of examples, discussed in this paper, deal with pH-responsive drug delivery system. Thermo-responsive polymer is also covered to a large extent, as well as double-responsive system. The physico-chemical behaviour underlying the phase transition will be discussed in brief. Then selected examples of applications are described.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Drug Delivery Systems*
  • Endosomes / metabolism
  • Excipients / chemistry
  • Genetic Therapy
  • Hot Temperature
  • Humans
  • Hydrogen-Ion Concentration
  • Polymers / chemistry*


  • Excipients
  • Polymers