Chemical release from single PMMA microparticles monitored by CARS microscopy
Konferensbidrag (offentliggjort, men ej förlagsutgivet), 2011

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.

Controlled release


Iodine carbamate

Diffusion coefficient

Non-linear microscopy

Coherent anti-stokes raman scattering

Third harmonic generation


Annika Enejder

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Fredrik Svedberg

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Lars Nordstierna

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Magnus Nydén

SuMo Biomaterials

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Multiphoton Microscopy in the Biomedical Sciences XI; San Francisco, CA; 23-25 January 2011

1605-7422 (ISSN)

Vol. 7903







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