Poly(2-oxazoline)s and their derivatives: a versatile polymer class with manifold application possibilities

Poly(2-oxazoline)s are a versatile class of polymers which can be obtained by cationic ring-opening polymerization. A broad range of different initiators, monomers and terminating agents allows the fine-tuning of the polymer properties. In this dissertation, the synthesis, characterization, and biological properties of poly(2-oxazoline)s and their derivatives, e.g. linear poly(ethylene imine), are presented. In addition, their suitability for different applications such as antifouling coatings, anticoagulants, and cancer therapy as well as drug and gene delivery, is investigated.Poly(2-oxazoline) sind eine vielseitige Polymerklasse, welche durch kationische Ringöffnungspolymerisation erhalten werden kann. Eine große Anzahl an verschiedenen Initiatoren, Monomeren und Abbruchreagenzien erlaubt die genaue Einstellung der (Co)polymer-Eigenschaften. In der vorliegenden Dissertation, werden die Synthese, die Charakterisierung und die biologischen Eigenschaften von Poly(2-oxazolinen) und ihren Derivaten, z.B. linearem Poly(ethylenimin), vorgestellt. Weiterhin wird ihre Eignung für verschiedene Anwendungsgebiete, z.B. für Antifoulingbeschichtungen, Wirkstofftransport und Gentransfer sowie für die Krebstherapie und als Antikoagulantien, untersucht

Poly(ethylene imine)s as Antimicrobial Agents with Selective Activity

We report the structure–activity relationship in the antimicrobial activity of linear and branched poly(ethylene imine)s (L‐ and B‐PEIs) with a range of molecular weights (MWs) (500–12 000). Both L‐ and B‐PEIs displayed enhanced activity against Staphylococcus aureus over Escherichia coli . Both B‐ and L‐PEIs did not cause any significant permeabilization of E. coli cytoplasmic membrane. L‐PEIs induced depolarization of S. aureus membrane although B‐PEIs did not. The low MW B‐PEIs caused little or no hemolysis while L‐PEIs are hemolytic. The low MW B‐PEIs are less cytotoxic to human HEp‐2 cells than other PEIs. However, they induced significant cell viability reduction after 24 h incubation. The results presented here highlight the interplay between polymer size and structure on activity. Unmodified poly(ethylene imine)s are shown to act as selective antibacterial agents. The mechanism of action is likely related to, but not exclusive to, interaction with cell walls and cell membrane damage. These molecules provide a cost effective and chemically facile framework for the further development of selective antimicrobial materials.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93579/1/mabi_201200052_sm_suppdata.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/93579/2/1279_ftp.pd

Early detection of disease progression after palliative chemotherapy in NSCLC patients by 18F-FDG-PET

SummaryAim: We investigated whether 18F-fluorodeo- xyglucose positron emission tomography (FDG-PET) is capable of detecting renewed disease progression earlier than computed tomography (CT) in patients with inoperable non-small cell lung cancer (NSCLC) who have undergone chemotherapy as part of a palliative treatment plan. Patients, methods: 18 patients were studied retrospectively. Three FDG-PET/CT scans for initial and follow-up diagnostic purposes were evaluated. Palliative chemotherapy was administered between the first FDG-PET/CT scan (t0) and the second (t1), followed by a treatment-free interval between the second FDG-PET/CT scan (t1) and the third (t2). Maximum standardized uptake values (SUVmax) and largest diameters of lesions were determined for PET scans and the corresponding CTs. Lesion-based and patient-based assessments were performed, as were assessments according to RECIST/PER- CIST. Results: 82 lesions were identified in 18 patients. In interval t1-t2, the increase in diameter in the lesion-based evaluation was 5.0% (non-significant), while the patient based evaluation showed a non-significant reduction of 2.8%. Considering PET, both the lesion-based and patient-based evaluations found a significant increase in SUVmax by a median of 30.4 % and 45.8 %, respectively. PERCIST criteria at time point t2 identified ten more patients with progression than did REC- IST. Conclusion: In patients with NSCLC, renewed progression during the treatment-free interval after palliative chemotherapy can be detected earlier with PET than with CT. Thus, FDG-PET appears to be a useful diagnostic imaging procedure regarding this aspect. Its clinical relevance should be investigated in further studies.</jats:p

Zwitterionic poly(2-oxazoline)s as promising candidates for blood contacting applications

The hemocompatibility and cytotoxicity of zwitterionic poly(2-oxazoline)s are investigated.</p

Linear poly(ethylene imine)s: true molar masses, solution properties and conformation

In-depth characterization of pharmaceutically relevant polymers plays a pivotal role in many areas, including nanoscience, gene therapy, analytical and polymer chemistry etc.</p