Browsing by Author "Larsson, Anette"

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Design and characterization of a novel amphiphilic chitosan nanocapsule-based thermo-gelling biogel with sustained in vivo release of the hydrophilic anti-epilepsy drug ethosuximide
(2012-08-10)
Hsiao, Meng-Hsuan
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Larsson, Mikael
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Larsson, Anette
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Evenbratt, Hanne
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Chen, Ying-Yu
Thermo-gelling injectable nanogels, with no burst release of loaded drug, were prepared by a simple route by combining self assembled nanocapsules of amphiphilically modified chitosan with glycerophosphate di-sodium salt and glycerol. The potential as a depot drug delivery system was demonstrated in vivo through the therapeutic effect of ethosuximide (ESM) loaded nanogels, suppressing spike wave discharges (SWDs) in Long Evan rat model. Simultaneously clearance of gels from the site of administration was monitored non-invasively using MRI. The gel structure was characterized using TEM and SEM, confirming the gels to be an assembly of nanocapsules and using two-photon microscopy to visualize the network structure. In vitro drug release studies using ESM revealed that the nanogels exhibited extended, mostly Fickian release. Finally, all investigated formulations displayed excellent cytotoxicity data determined by MTT assay using human retinal pigmented epithelium cells. All presented properties are highly desirable for injectable depot gels for drug delivery. (c) 2012 Elsevier B.V. All rights reserved.
Evaluation of Carboxymethyl-Hexanoyl Chitosan as a Protein Nanocarrier
(2013-06-18)
Larsson, Mikael
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Borde, Annika
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Mattisson, Emma
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Liu, Dean-Mo
;
Larsson, Anette
Carboxymethyl-hexanoyl chitosan (CHC) has the ability to self-assemble into nanocapsules in an aqueous solution and it has recently shown potential in numerous biomedical applications. Here we investigate the protein loading efficiency and release, as well as the structural properties of CHC protein nanocarriers. Bovine serum albumin (BSA) or its chromophore labelled version, fluorescein-BSA, was used as a model protein and the loading was performed with a simple mixing of pre-formed nanocapsules and protein. Dynamic light scattering and zeta potential analysis revealed that protein loaded nanocarriers with high positive zeta potential were formed. The protein loaded nanocarriers displayed a loading efficiency of 75% and a very slow protein release. In summary, our results highlight the potential of CHC as a protein nanocarrier, but also indicate that protein-CHC interactions need to be considered in protein containing CHC formulations where protein release is not the main function.