@article{ZahoranovaLuxenhofer2021, author = {Zahoranov{\´a}, Anna and Luxenhofer, Robert}, title = {Poly(2-oxazoline)- and Poly(2-oxazine)-Based Self-Assemblies, Polyplexes, and Drug Nanoformulations—An Update}, series = {Advanced Healthcare Materials}, volume = {10}, journal = {Advanced Healthcare Materials}, number = {6}, doi = {10.1002/adhm.202001382}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225833}, year = {2021}, abstract = {For many decades, poly(2-oxazoline)s and poly(2-oxazine)s, two closely related families of polymers, have led the life of a rather obscure research topic with only a few research groups world-wide working with them. This has changed in the last five to ten years, presumably triggered significantly by very promising clinical trials of the first poly(2-oxazoline)-based drug conjugate. The huge chemical and structural toolbox poly(2-oxazoline)s and poly(2-oxazine)s has been extended very significantly in the last few years, but their potential still remains largely untapped. Here, specifically, the developments in macromolecular self-assemblies and non-covalent drug delivery systems such as polyplexes and drug nanoformulations based on poly(2-oxazoline)s and poly(2-oxazine)s are reviewed. This highly dynamic field benefits particularly from the extensive synthetic toolbox poly(2-oxazoline)s and poly(2-oxazine)s offer and also may have the largest potential for a further development. It is expected that the research dynamics will remain high in the next few years, particularly as more about the safety and therapeutic potential of poly(2-oxazoline)s and poly(2-oxazine)s is learned.}, language = {en} } @article{ShityakovBroscheitFoerster2013, author = {Shityakov, Sergey and Broscheit, Jens and F{\"o}rster, Carola}, title = {Multidrug resistance protein P-gp interaction with nanoparticles (fullerenes and carbon nanotube) to assess their drug delivery potential: a theoretical molecular docking study.}, series = {International journal of computational biology and drug design}, volume = {6}, journal = {International journal of computational biology and drug design}, number = {4}, doi = {10.1504/IJCBDD.2013.056801}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132089}, pages = {343-357}, year = {2013}, abstract = {P-glycoprotein (P-gp)-mediated efflux system plays an important role to maintain chemical balance in mammalian cells for endogenous and exogenous chemical compounds. However, despite the extensive characterisation of P-gp potential interaction with drug-like molecules, the interaction of carbon nanoparticles with this type of protein molecule is poorly understood. Thus, carbon nanoparticles were analysed, such as buckminsterfullerenes (C20, C60, C70), capped armchair single-walled carbon nanotube (SWCNT or C168), and P-gp interactions using different molecular docking techniques, such as gradient optimisation algorithm (ADVina), Lamarckian genetic algorithm (FastDock), and shape-based approach (PatchDock) to estimate the binding affinities between these structures. The theoretical results represented in this work show that fullerenes might be P-gp binders because of low levels of Gibbs free energy of binding (ΔG) and potential of mean force (PMF) values. Furthermore, the SWCNT binding is energetically unfavourable, leading to a total decrease in binding affinity by elevation of the residual area (Ares), which also affects the π-π stacking mechanisms. Further, the obtained data could potentially call experimental studies using carbon nanostructures, such as SWCNT for development of drug delivery vehicles, to administer and assess drug-like chemical compounds to the target cells since organisms probably did not develop molecular sensing elements to detect these types of carbon molecules.}, language = {en} } @article{SchulzJakschSchubeletal.2014, author = {Schulz, Anita and Jaksch, Sebastian and Schubel, Rene and Wegener, Erik and Di, Zhenyu and Han, Yingchao and Meister, Annette and Kressler, J{\"o}rg and Kabanov, Alexander V. and Luxenhofer, Robert and Papadakis, Christine M. and Jordan, Rainer}, title = {Drug-Induced Morphology Switch in Drug Delivery Systems Based on Poly(2-oxazoline)s}, series = {ACS Nano}, volume = {8}, journal = {ACS Nano}, number = {3}, doi = {10.1021/nn406388t}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120766}, pages = {2686-96}, year = {2014}, abstract = {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.}, language = {en} } @article{LuebtowMarciniakSchmiedeletal.2019, author = {L{\"u}btow, Michael M. and Marciniak, Henning and Schmiedel, Alexander and Roos, Markus and Lambert, Christoph and Luxenhofer, Robert}, title = {Ultra-high to ultra-low drug loaded micelles: Probing host-guest interactions by fluorescence spectroscopy}, series = {Chemistry - A European Journal}, volume = {25}, journal = {Chemistry - A European Journal}, number = {54}, doi = {10.1002/chem.201902619}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206128}, pages = {12601-12610}, year = {2019}, abstract = {Polymer micelles are an attractive means to solubilize water insoluble compounds such as drugs. Drug loading, formulations stability and control over drug release are crucial factors for drug-loaded polymer micelles. The interactions between the polymeric host and the guest molecules are considered critical to control these factors but typically barely understood. Here, we compare two isomeric polymer micelles, one of which enables ultra-high curcumin loading exceeding 50 wt.\%, while the other allows a drug loading of only 25 wt.\%. In the low capacity micelles, steady-state fluorescence revealed a very unusual feature of curcumin fluorescence, a high energy emission at 510 nm. Time-resolved fluorescence upconversion showed that the fluorescence life time of the corresponding species is too short in the high-capacity micelles, preventing an observable emission in steady-state. Therefore, contrary to common perception, stronger interactions between host and guest can be detrimental to the drug loading in polymer micelles.}, subject = {Polymer-drug interaction}, language = {en} } @article{HuettenDhanasinghHessleretal.2014, author = {H{\"u}tten, Mareike and Dhanasingh, Anandhan and Hessler, Roland and St{\"o}ver, Timo and Esser, Karl-Heinz and M{\"o}ller, Martin and Lenarz, Thomas and Jolly, Claude and Groll, J{\"u}rgen and Scheper, Verena}, title = {In Vitro and In Vivo Evaluation of a Hydrogel Reservoir as a Continuous Drug Delivery System for Inner Ear Treatment}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0104564}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119375}, pages = {e104564}, year = {2014}, abstract = {Fibrous tissue growth and loss of residual hearing after cochlear implantation can be reduced by application of the glucocorticoid dexamethasone-21-phosphate-disodium-salt (DEX). To date, sustained delivery of this agent to the cochlea using a number of pharmaceutical technologies has not been entirely successful. In this study we examine a novel way of continuous local drug application into the inner ear using a refillable hydrogel functionalized silicone reservoir. A PEG-based hydrogel made of reactive NCO-sP(EO-stat-PO) prepolymers was evaluated as a drug conveying and delivery system in vitro and in vivo. Encapsulating the free form hydrogel into a silicone tube with a small opening for the drug diffusion resulted in delayed drug release but unaffected diffusion of DEX through the gel compared to the free form hydrogel. Additionally, controlled DEX release over several weeks could be demonstrated using the hydrogel filled reservoir. Using a guinea-pig cochlear trauma model the reservoir delivery of DEX significantly protected residual hearing and reduced fibrosis. As well as being used as a device in its own right or in combination with cochlear implants, the hydrogel-filled reservoir represents a new drug delivery system that feasibly could be replenished with therapeutic agents to provide sustained treatment of the inner ear.}, language = {en} } @article{HoyerSchatzschneiderSchulzSiegmundetal.2012, author = {Hoyer, Jan and Schatzschneider, Ulrich and Schulz-Siegmund, Michaela and Neundorf, Ines}, title = {Dimerization of a cell-penetrating peptide leads to enhanced cellular uptake and drug delivery}, series = {Beilstein Journal of Organic Chemistry}, volume = {8}, journal = {Beilstein Journal of Organic Chemistry}, doi = {10.3762/bjoc.8.204}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133933}, pages = {1788-1797}, year = {2012}, abstract = {Over the past 20 years, cell-penetrating peptides (CPPs) have gained tremendous interest due to their ability to deliver a variety of therapeutically active molecules that would otherwise be unable to cross the cellular membrane due to their size or hydrophilicity. Recently, we reported on the identification of a novel CPP, sC18, which is derived from the C-terminus of the 18 kDa cationic antimicrobial protein. Furthermore, we demonstrated successful application of sC18 for the delivery of functionalized cyclopentadienyl manganese tricarbonyl (cymantrene) complexes to tumor cell lines, inducing high cellular toxicity. In order to increase the potential of the organometallic complexes to kill tumor cells, we were looking for a way to enhance cellular uptake. Therefore, we designed a branched dimeric variant of sC18, (sC18)\(_2\), which was shown to have a dramatically improved capacity to internalize into various cell lines, even primary cells, using flow cytometry and fluorescence microscopy. Cell viability assays indicated increased cytotoxicity of the dimer presumably caused by membrane leakage; however, this effect turned out to be dependent on the specific cell type. Finally, we could show that conjugation of a functionalized cymantrene with (sC18)\(_2\) leads to significant reduction of its IC\(_{50}\) value in tumor cells compared to the respective sC18 conjugate, proving that dimerization is a useful method to increase the drug-delivery potential of a cell-penetrating peptide.}, language = {en} }