Synthesis, aqueous solution behavior and layer-bylayer self-assembly of poly(2-alkyl-2-oxazoline)s


Thesis Type: Doctorate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Arts and Sciences, Department of Chemistry, Turkey

Approval Date: 2019

Student: EDA ÇAĞLI

Supervisor: İREM EREL GÖKTEPE

Abstract:

Poly(2-alkyl-2-oxazoline)s (PAOXs), are of interest for biomedical applications due to their important biological properties such as nontoxicity and biocompatibility. PAOXs with short-alkyl chains exhibit temperature-responsive behaviour which is advantageous for various biomedical applications. This dissertation focused on synthesis, aqueous solution behaviour, post-functionalization and layer-by-layer (LbL) self-assembly of PAOXs. In addition, it aimed to examine the surface properties of PAOX LbL films and correlate them with biological properties of the multilayers. First, the effect of pH on aqueous solution behaviour of poly(2-isopropyl-2-oxazoline) (PIPOX) was examined. In this respect, the effect of PIPOX end group, concentration of polymer and salt on pH-induced self-association of PIPOX was examined. Second, the effect of PIPOX end-group on loading capacity and release profile of a model antibiotic, Chloramphenicol (CAP) from PIPOX aggregates was investigated at neutral and acidic pH at a physiologically related temperature. Third, the effect of side chain variation on surface and biological properties of PAOX LbL films has been examined. In this context, PAOXs with varying side chains were co-assembled with Tannic Acid (TA) at the surface using LbL technique. The effect of chemical nature of PAOX side chains, phase behaviour of PAOX and the binding strength between the layers on surface morphology, stability, wettability and stimuli-responsive drug release properties of the films were examined and correlated with anti-adhesive and antibacterial properties of the PAOX multilayers. Forth, PIPOX-hyd-Doxycycline conjugate was synthesized via hydrazone bond formation and characterized. Overall, this dissertation generated fundamental knowledge about aqueous solution behaviour of PAOXs and structure-property relationship in PAOX multilayer films.