Characterization & Mathematical Modeling of Silk Based Drug Release Systems.
Hines, Daniel.
2012
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Abstract: Silk fibroin has demonstrated its utility as a natural polymeric
biomaterial for the development of polymeric controlled release systems. However, further
characterization of relevant release mechanisms and release kinetics of these systems is
required in order to fully understand and utilize this material. A methodology towards
characterizing the release mechanisms and release kinet... read moreics of silk fibroin-based controlled
drug release systems is presented. This methodology is accomplished in a four step process
of collecting robust in vitro release data, characterizing the appropriate release
mechanisms via model fitting, identifying model-parameter-material relationships, and
approximating model parameter material relationships with empirical expressions. These
empirical expressions are then used to predict model parameters allowing simulation of
release. The methodology is demonstrated for two cases, FITC-dextran release from silk
films and synthetic dye release from silk films. In both cases a diffusion mechanism is
identified as the release mechanism. Binding of synthetic dyes to silk is also assessed and
the existence of a more complex desorption-diffusion release mechanism is considered. In
most cases binding of the dye to the silk was too weak for desorption to perturb an
exclusively diffusional release mechanism. In addition, a novel continuous flow dissolution
apparatus for the collection of in vitro release data was constructed and utilized for the
synthetic dye release study. This system allows the collection of data sets while avoiding
experimental errors through automation and the increase in the number of observations per
release sample based on analysis by real time UV-Vis spectroscopy. This reduction of
experimental error and increase in amount of data per sample yields more accurate parameter
estimates from mechanistic model fitting. The results from these studies contribute to the
characterization of silk as an important alternative biomaterial to current leading
polymeric materials for fabricating controlled release devices.
Thesis (Ph.D.)--Tufts University, 2012.
Submitted to the Dept. of Chemical and Biological Engineering.
Advisor: David Kaplan.
Committee: Kyongbum Lee, Anthony Barry, and Bruce Paniliatis.
Keywords: Chemical engineering, Biomedical engineering, and Pharmaceutical sciences.read less - ID:
- kh04f212m
- Component ID:
- tufts:20857
- To Cite:
- DCA Citation Guide EndNote
