TY  - JOUR
A1  - Velk, Natalia
A1  - Uhlig, Katja
A1  - Vikulina, Anna
A1  - Duschl, Claus
A1  - Volodkin, Dmitry
T1  - Mobility of lysozyme in poly(L-lysine)/hyaluronic acid multilayer films
JF  - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin ; B, Biointerfaces
N2  - The spatial and temporal control over presentation of protein-based biomolecules such as growth factors and hormones is crucial for in vitro applications to mimic the complex in vivo environment. We investigated the interaction of a model protein lysozyme (Lys) with poly(L-lysine)/hyaluronic acid (PLL/HA) multilayer films. We focused on Lys diffusion as well as adsorption and retention within the film as a function of the film deposition conditions and post-treatment. Additionally, an effect of Lys concentration on its mobility was probed. A combination of confocal fluorescence microscopy, fluorescence recovery after photobleaching, and microfluidics was employed for this investigation. Our main finding is that adsorption of PLL and HA after protein loading induces acceleration and reduction of Lys mobility, respectively. These results suggest that a charge balance in the film to a high extent governs the protein-film interaction. We believe that control over protein mobility is a key to reach the full potential of the PLL/HA films as reservoirs for biomolecules depending on the application demand. (C) 2016 The Authors. Published by Elsevier B.V.
KW  - Layer-by-layer
KW  - Protein
KW  - Diffusion
KW  - Release
KW  - FRAP
Y1  - 2016
U6  - https://doi.org/10.1016/j.colsurfb.2016.07.055
SN  - 0927-7765
SN  - 1873-4367
VL  - 147
SP  - 343
EP  - 350
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wöhl-Bruhn, Stefanie
A1  - Badar, Muhammad
A1  - Bertz, Andreas
A1  - Tiersch, Brigitte
A1  - Koetz, Joachim
A1  - Menzel, Henning
A1  - Müller, Peter P.
A1  - Bunjes, Heike
T1  - Comparison of in vitro and in vivo protein release from hydrogel systems
JF  - Journal of controlled release
N2  - Hydrogel systems based on hydroxyethyl starch-polyethylene glycol methacrylate (HES-P(EG)(6)MA) or hydroxyethyl starch methacrylate (HES-MA) were used to assess the protein release behavior. Here, we analyzed the in vitro release of FITC-anti-human antibodies incorporated in either HES-P(EG)(6)MA or HES-MA hydrogel delivery systems in PBS or human serum. In addition, hydrogel disks and microparticles prepared from the two polymers were subcutaneously implanted in BALB/c mice. The in vivo release of FITC-IgG was non-invasively monitored by an in vivo imaging system (IVIS 200) over a time period of up to 3 months. The imaging system allowed to asses individual animals over time, therefore only a small number of animals was required to obtain high quality data. The reduction in fluorescence intensity at the site of administration was compared to in vitro release profiles. These investigations demonstrated a sustained release from HES-MA hydrogel disks compared to rapidly degrading HES-P(EG)(6)MA disks and microparticles. The sustained release from HES-MA disks could be further optimized by using increased polymer concentrations. Human serum as in vitro release medium reflected better the in vivo release from HES-P(EG)(6)MA systems than PBS, suggesting that the presence of organic substances like proteins or lipids may play a significant role for the release kinetics.
KW  - In vivo imaging system (IVIS)
KW  - Hydrogel disks
KW  - Hydrogel microparticles
KW  - Release
KW  - In vivo-in vitro correlation
KW  - Hydroxyethyl starch (HES)
Y1  - 2012
U6  - https://doi.org/10.1016/j.jconrel.2012.05.049
SN  - 0168-3659
VL  - 162
IS  - 1
SP  - 127
EP  - 133
PB  - Elsevier
CY  - Amsterdam
ER  -