Model for Microcapsule Drug Release with Ultrasound-Activated Enhancement.
Tsao, Nadia H
Langmuir : the ACS journal of surfaces and colloids
American Chemical Society
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Tsao, N. H., & Hall, L. (2017). Model for Microcapsule Drug Release with Ultrasound-Activated Enhancement.. Langmuir : the ACS journal of surfaces and colloids, 33 (45), 12960-12972. https://doi.org/10.1021/acs.langmuir.7b02954
Microbubbles and microcapsules of silane-polycaprolactone (SiPCL) have been filled with a fluorescent acridium salt (lucigenin) as a model for a drug loaded delivery vehicle. The uptake and delivery was studied and compared with similar microbubbles and microcapsules of silica/mercaptosilica (S/M/S). Positively charged lucigenin was encapsulated through an electrostatic mecha-nism, following a Type I Langmuir isotherm as expected, but with additional multilayer uptake that leads to much higher loading for the SiPCL system (~280 µg/2.4 × 109 microcapsules compared with ~135 µg/2.4 × 109 microcapsules for S/M/S). Whereas luci-genin release from the S/M/S bubbles and capsules loaded below the solubility limit is consistent with diffusion from a mono-lithic structure, the SiPCL structures show distinct release patterns; the Weibull function predicts a general trend for diffusion from normal Euclidean space at short times tending towards diffusion out of fractal spaces with increasing time. As a slow release sys-tem, the dissolution time (Td) increases from 1 – 2 days for the S/M/S and the low concentration loaded SiPCl vehicles to ~10 days for the high loaded microcapsule. However, the Td can be reduced on insonation to 2 days, indicating the potential to gain control over local enhanced release with ultrasound. This was tested for a docetaxel model and its effect of C4-2B prostate cancer cells, showing improved cell toxicity for concentrations below the normal EC50 in solution.
Silicon Dioxide, Capsules, Drug Delivery Systems, Solubility, Drug Liberation
External DOI: https://doi.org/10.1021/acs.langmuir.7b02954
This record's URL: https://www.repository.cam.ac.uk/handle/1810/271220