TY  - JOUR
A1  - Schulz, Anita
A1  - Jaksch, Sebastian
A1  - Schubel, Rene
A1  - Wegener, Erik
A1  - Di, Zhenyu
A1  - Han, Yingchao
A1  - Meister, Annette
A1  - Kressler, Jörg
A1  - Kabanov, Alexander V.
A1  - Luxenhofer, Robert
A1  - Papadakis, Christine M.
A1  - Jordan, Rainer
T1  - Drug-Induced Morphology Switch in Drug Delivery Systems Based on Poly(2-oxazoline)s
JF  - ACS Nano
N2  - Defined aggregates of polymers such as polymeric micelles are of great importance in the development of pharmaceutical formulations. The amount of drug that can be formulated by a drug delivery system is an important issue, and most drug delivery systems suffer from their relatively low drug-loading capacity. However, as the loading capacities increase, i.e., promoted by good drug–polymer interactions, the drug may affect the morphology and stability of the micellar system. We investigated this effect in a prominent system with very high capacity for hydrophobic drugs and found extraordinary stability as well as a profound morphology change upon incorporation of paclitaxel into micelles of amphiphilic ABA poly(2-oxazoline) triblock copolymers. The hydrophilic blocks A comprised poly(2-methyl-2-oxazoline), while the middle blocks B were either just barely hydrophobic poly(2-n-butyl-2-oxazoline) or highly hydrophobic poly(2-n-nonyl-2-oxazoline). The aggregation behavior of both polymers and their formulations with varying paclitaxel contents were investigated by means of dynamic light scattering, atomic force microscopy, (cryogenic) transmission electron microscopy, and small-angle neutron scattering. While without drug, wormlike micelles were present, after incorporation of small amounts of drugs only spherical morphologies remained. Furthermore, the much more hydrophobic poly(2-n-nonyl-2-oxazoline)-containing triblock copolymer exhibited only half the capacity for paclitaxel than the poly(2-n-butyl-2-oxazoline)-containing copolymer along with a lower stability. In the latter, contents of paclitaxel of 8 wt % or higher resulted in a raspberry-like micellar core.
KW  - amphiphilic poly(2-oxazoline)s
KW  - paclitaxel
KW  - drug delivery
KW  - rod-to-sphere transition
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120766
N1  - This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html), which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
VL  - 8
IS  - 3
ER  -