Barrier properties of biological hydrogel filters
Final Report Abstract
During the funding period, we have investigated the permeability properties of two biological hydrogels: the vitreous humor and reconstituted neurofilament networks. In both systems, we found that electrostatic interactions give rise to retarded diffusion of test particles. In the vitreous humor, we were able to identify the glycosaminoglycans (GAGs) hyaluronic acid and heparan sulfate as molecular key components responsible for establishing selectivity. High salt concentrations resulted in an effective charge screening and mobilized the formerly trapped particles. In neurofilaments networks, we also found strong indications for electrostatic trapping. However, for liposome particles, we observed that the mobility of the particles also depends on the geometry of lipids the liposomes are assembled from. We attributed this observation to hydrophobic interactions between the neurofilament side arms and the hydrophobic region of the lipid bilayer which is made accessible when lipids with an inverted cone geometry are present in the lipid shell at sufficiently high concentrations. First results obtained with an engineered capillary system demonstrate that the physico-chemical principles which render biological hydrogels selective can be transferred to artificial filtration systems. One prerequisite for such a strategy is to identify the molecular key components which are responsible for the selective permeability of biological hydrogels and to combine those key molecules with a carrier matrix.
Publications
- Diffusion Regulation in the vitreous humor, Biophysical Journal, 109(10):2171-2181 (2015)
B. Käsdorf, F. Arends and O. Lieleg
(See online at https://doi.org/10.1016/j.bpj.2015.10.002) - An optimized purification process for porcine gastric mucin with preservation of its native functional properties, RSC Advances, 6, 44932-44943 (2016)
V.J. Schöming, B.T. Käsdorf, Ch. Scholz, K. Bidmon, O. Lieleg and S. Berensmeier
(See online at https://doi.org/10.1039/c6ra07424c) - Lipid head group charge and fatty acid configuration dictate liposome mobility in neurofilament gels, Macromolecular Bioscience
F. Arends, H. Chaudhary, P. Janmey, M.M.A.E. Claessens, and O. Lieleg
(See online at https://doi.org/10.1002/mabi.201600229)
