Poly(2-oxazolines) (POxs) are a class of polymers that have gained significant interest in biomedical applications. POxs are mainly synthesized using living cationic ring-opening polymerization (CROP) under microwave irradiation. POxs are considered pseudo-polypeptides because they are similar to polypeptides. Nevertheless, they are more chemically stable than polypeptides due to the presence of tertiary amides. POxs
The major goal of this research is to synthesize and characterize a novel well-defined amphiphilic block copolymer based on POxs. These amphiphilic block copolymers can comprise core cross-linked star polymers (CCS) or linear block copolymers. This research demonstrates and describes the synthesis of poly(2-methyl-2-oxazoline-b-poly(2,2'-(1,4-phenylene)bis-2-oxazoline)-co-(2-n-2-butyl-2-oxazoline)(PMeOx-b-P(PhenBisOx-co-ButOx) amphiphilic core cross-linked star polymers (CCS) based on POxs. The CCS polymers are synthesized via sequential CROP in two steps by synthesizing Poly(2-methyl-2-oxazoline) (PMeOx) as the living arms followed by cross-linking of the core 2, 2’-(1,4-phenylene)bis-2-oxazoline (PhenBisOx) as the cross-linker and 2-n-butyl-2-oxazoline (ButOx) as a hydrophobic monomer to form the core of the CCS polymers. In addition, this research will clarify the other kinds of amphiphilic copolymers based on aggregation-induced emission (AIE) fluorophores, tetraphenylethylene (TPE) as an initiator that have been synthesized by a combination of cationic and anionic ROP. First, the difunctional initiator TPE-(OH)2 was synthesized via McMurry coupling reaction. Then, two kinds of triblock copolymers, TPE-poly(2-methyl-2-oxazoline)-b-poly(ε-caprolactone) (TPE-(PMeOx-b-PCL)2) and TPE-poly(ε-caprolactone)-b-poly(2-methyl-2-oxazoline) (TPE-(PCL-b-PMeOx)2), were synthesized by altering the sequence of polymerization.
The resulting polymers, CCS polymers and the triblock copolymers were loaded with the anticancer drug doxorubicin (DOX) and their in vitro properties, cytotoxicity, and drug release at different pH were studied. Furthermore, the resulting polymers were characterized by size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and transmission electron microscopy (TEM). All results in this research showed that the amphiphilic block copolymers, the CCS polymers and the triblock copolymers could be suitable carriers for drug delivery systems.
|Date of Award||Nov 28 2022|
|Original language||English (US)|
- Physical Sciences and Engineering
|Supervisor||Nikos Hadjichristidis (Supervisor)|