Simultaneous release of hydrophobic and cationic solutes from thin-film "plum-pudding" gels: A multifunctional platform for surface drug delivery?

Research output: Contribution to journalArticle


The release of two compositionally different solutes from a composite gel composed of two different populations of microgel particles embedded in a single bulk gel matrix is described, showing the potential of the "plum-pudding gel" as a multifunctional platform for controlled surface release. One hydrophobic solute (pyrene) and one hydrophobic and charged solute (rhodamine 123) were chosen as the solutes to be released. Hydrophobic microgels composed of 50% N-isopropylacrylamide (NIPAM) and 50% N-tert-butylacrylamide (BAM) were loaded with pyrene, and anionic microgels composed of 30% acrylic acid (AAc), 20% NIPAM, and 50% BAM were loaded with rhodamine 123. The two solute-loaded microgel populations were incorporated into a single bulk gel network, from which the two solutes were released simultaneously and independently. Using this structural motif, solutes that are mutually incompatible can be incorporated into a single matrix with which they may also be incompatible. The electrostatically incorporated solute was released much more slowly than the hydrophobically attracted solute, indicating that the microgel composition can be tailored to the specific solute, and thus control its release rate. The choice of bulk matrix was also found to influence the release rate much more than expected, offering a further control element to the system.


  • Iseult Lynch
  • P de Gregorio
  • K A Dawson
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)6257-6261
JournalThe Journal of Physical Chemistry Part B
Issue number13
Publication statusPublished - 2005
Publication categoryResearch