Chemical release from single PMMA microparticles monitored by CARS microscopy

Annika Enejder*, Fredrik Svedberg, Lars Nordstierna, Magnus Nydén

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

8 Citations (Scopus)


Microparticles loaded with antigens, proteins, DNA, fungicides, and other functional agents emerge as ideal vehicles for vaccine, drug delivery, genetic therapy, surface- and crop protection. The microscopic size of the particles and their collective large specific surface area enables highly active and localized release of the functional substance. In order to develop designs with release profiles optimized for the specific application, it is desirable to map the distribution of the active substance within the particle and how parameters such as size, material and morphology affect release rates at single particle level. Current imaging techniques are limited in resolution, sensitivity, image acquisition time, or sample treatment, excluding dynamic studies of active agents in microparticles. Here, we demonstrate that the combination of CARS and THG microscopy can successfully be used, by mapping the spatial distribution and release rates of the fungicide and food preservative IPBC from different designs of PMMA microparticles at single-particle level. By fitting a radial diffusion model to the experimental data, single particle diffusion coefficients can be determined. We show that release rates are highly dependent on the size and morphology of the particles. Hence, CARS and THG microscopy provides adequate sensitivity and spatial resolution for quantitative studies on how single-particle properties affect the diffusion of active agents at microscopic level. This will aid the design of innovative microencapsulating systems for controlled release.

Original languageEnglish
Title of host publicationMultiphoton Microscopy in the Biomedical Sciences XI
EditorsAmmasi Periasamy, Karsten König, Peter T. C. So
Place of PublicationBellingham, WA
Number of pages8
ISBN (Print)9780819484406
Publication statusPublished - 2011
Externally publishedYes
EventMultiphoton Microscopy in the Biomedical Sciences XI - San Francisco, CA, United States
Duration: 23 Jan 201125 Jan 2011

Publication series

NameProceedings of SPIE
ISSN (Print)1605-7422


ConferenceMultiphoton Microscopy in the Biomedical Sciences XI
Country/TerritoryUnited States
CitySan Francisco, CA


  • Non-linear microscopy
  • Coherent anti-Stokes Raman Scattering
  • Third Harmonic Generation
  • microparticles
  • controlled release
  • diffusion coefficient
  • iodine carbamate


Dive into the research topics of 'Chemical release from single PMMA microparticles monitored by CARS microscopy'. Together they form a unique fingerprint.

Cite this