POLYELECTROLYTES FOR MEDICINE
- Birgit Urban (Research Engineer)
- David Vehlow (PhD student)
- Mieke L. Möller
Areas of research
In the group Polyelectrolytes for Medicine soft particles and coatings based on the complexation of oppositely charged polyelectrolytes (PEL) are generated, which have applications in the biomedical and pharmaceutical field. PEL complex (PEC) nanoparticles (NP) are prepared by controlled mixing of biorelated polycation and polyanion solutions followed by typical colloid refinement steps (centrifugation, filtration, ultrasonification). The formed turbid dispersions contain PEC NP with diameters of 10 - 500 nm consisting of a neutral core and a charged shell. Their net charge (sign and magnitude) can be controlled by the molar excess of either cationic or anionic repeating units, their size by molecular weight, ionic strength and pH and their shape (spherical or rod-like) by molecular flexibility or stiffness of the used PELs. PEC coatings are prepared either by solution casting of PEC NP or by consecutive adsorption from polycation and polyanion solutions (layer-by-layer technique). Importantly, PEC NP and PEC coatings can be loaded with relevant drugs or functional proteins during or after the polyelectrolyte mixing step aiming at their controlled release.
One medical application field of PEC NP and PEC coatings is the functionalization of devices, implants, bone substitute materials (BSM) and artificial tissue, which is developed within SFB TRR 79 (Project M7). Therein PEC NP loaded with osteoinductive drugs are applied to functionalize bone cements and osteosynthetic plates aiming at the locally confined and timely sustained therapy of fractures within systemically (osteoporosis, multiple myeloma) altered bone.
In cooperation with medical, cell biological and material scientists our research on PEC NP addresses:
- Colloid stability (shipping, storage)
- Wet adhesiveness at BSM (biofluid contact)
- Sterility, cytocompatibility, immunocompatibility
- Switchable and sustained drug release
A second application field is dedicated to either bioactive coatings, where functional pro-teins and enzymes are immobilized by chemical or electrostatic linkage, or biopassive coa-tings, where protein adsorption is reduced by electrostatic repulsion and tight water shell.
- DFG: Transregio SFB 79 - Part Project M7: Materials for tissue regeneration within systemically altered bone (2010-2018)
5 most important publications
- Starchenko, V.; Müller, M.; Lebovka, N. J. Phys. Chem. B 2012, 116, 14961-14967.
- Polyelectrolyte complexes in the dispersed and solid state, Advances in Polymer Science 2014, 255 & 256 (Müller, M. ed.), Springer, Heidelberg
- Woltmann, B., Torger, B., Müller, M., Hempel, U., International Journal of Nanomedicine 2014, 9, 2015-2025.
- Müller, M., Torger, B., Vehlow, D., Urban, B., Wehrum, D., Woltmann, B., Hempel, U., Biointerphases 2015, 10(1), 011001-011010.
- Müller, M., Urban, B., Macromolecular Chemistry and Physics 2016, 217(21), 2360-2371.