Hoffmann, S.; Gorzelanny, C.; Moerschbacher, B.; Goycoolea, F.M. Physicochemical Characterization of FRET-Labelled Chitosan Nanocapsules and Model Degradation Studies. Nanomaterials2018, 8, 846.
Hoffmann, S.; Gorzelanny, C.; Moerschbacher, B.; Goycoolea, F.M. Physicochemical Characterization of FRET-Labelled Chitosan Nanocapsules and Model Degradation Studies. Nanomaterials 2018, 8, 846.
Sub-micron o/w emulsions coated with chitosan have been used for drug delivery, quorum sensing inhibition and vaccine development. To study interactions with biological systems, nanocapsules have been fluorescently labelled in previous works, but it is often difficult to distinguish the released label from intact nanocapsules. In this study, we present advanced labelling strategies based on FRET measurements for chitosan-coated nanocapsules and investigate their dissolution and degradation. We used FRET measurements of nanocapsules loaded with equimolar concentrations of two fluorescent dyes in their oily core and correlated them with DLS count rate measurement and absorbance measurements during their disintegration by dissolution. Using count rate measurements, we also investigated the enzymatic degradation of nanocapsules using pancreatin and how protein corona formation influences their degradation. Of note, nanocapsules dissolved in ethanol, where FRET decreased simultaneously with count rate, and absorbance caused by nanocapsule turbidity, indicating increased distance between dye molecules after their release. Nanocapsules were degradable by pancreatin in a dose dependent manner, and showed a delayed enzymatic degradation after protein corona formation. We present here novel labelling strategies for nanocapsules that allow us to judge their status and an in vitro method to study nanocapsule degradation and the influence of surface characteristics.
chitosan; nanocapsules; degradation; FRET; protein corona; bioimaging
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