Unit:
Κατεύθυνση Επιστήμη Πολυμερών και Εφαρμογές τηςLibrary of the School of Science
Author:
Stavroulaki Dimitra
Supervisors info:
Ιατρού Ερμόλαος, Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ
Πιτσικάλης Μαρίνος, Καθηγητής , Τμήμα Χημείας, ΕΚΠΑ
Σακελλαρίου Γεώργιος, Επίκουρος Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ
Original Title:
Σύνθεση δισυσταδικών τριπολυμερών πολυ(αιθυλενοξειδίου)-b-πολυ(L-ιστιδίνη-co-L-αλανίνη) και μελέτη της επίδρασης της L-αλανίνης στη συσσωμάτωση και την δευτεροταγή δομή.
Translated title:
Synthesis of diblock terpolymers of poly(ethylene oxide)-b-poly(L-histidine-co-L-alanine) and study of the influence of the L-alanine on the aggregation and the secondary structure.
Summary:
In the present research project is presented the synthesis of a series of hybrid polypeptide copolymers of the type PEO-b-P(His-co-Ala) with different rates 10%, 20%, 40% Ala/His, as well as the synthesis of the diblock copolymer PEO-b-PAla. The synthesis of polymers was achieved through ring-opening polymerization (ROP) process of the corresponding protected N-carboxy anhydrides (monomers), using an amine end-functionalized poly(ethylene oxide) (m-PEO-NH2) macroinitiator. High-vacuum techniques were used for the synthesis of N-carboxy anhydrides of a-amino acids, for the purification of solvents and for the isolation of well-defined polymers as well, ensuring the high purity of the system. The successful synthesis of the polymers was confirmed by size exclusion chromatography (SEC), proton nuclear magnetic resonance (1H-NMR) and infrared spectroscopy (FT-IR). In addition, the relation between the secondary structure of the polypeptides and the pH and temperature was studied, using the technique of circular dichroism (CD). Finally, dynamic light scattering (DLS) and static light scattering (SLS) were used, in order to investigate the ability of the polypeptides to self-assemble into micelles, as well as their size. These amphiphilic copolymers of the PEO-b-P(His-co-Ala) type possess the ability to self-assemble in aqueous media and form micelle-like nanostructures. The outer hydrophilic corona of the nanostructures was comprised of poly(ethylene oxide) chains, while the pH-responsive core was based on PHis and PAla. PΑla was used as a hydrophobic component. The ultimate goal is to create novel hybrid drug delivery systems, which will be used for targeted and controlled drug release applications to cancer cells.
Main subject category:
Science
Other subject categories:
Chemistry
Keywords:
polypeptides, ring-opening polymerization, Ν-carboxy anhydrides, secondary structure, drug delivery
