Dissertation > Excellent graduate degree dissertation topics show

Synthesis and Multifunctional Modification of Amphiphilic Copolyester Based on Polyphosphoesters

Author: ShaoHaiYan
Tutor: NiPeiHong
School: Suzhou University
Course: Polymer Chemistry and Physics
Keywords: Polyphosphoester Amphiphilic Copolymers Michael-Type Reaction Thiol-Ene Reaction Biodegradability Self-Assemble Drug Delivery
CLC: O631.3
Type: Master's thesis
Year: 2012
Downloads: 55
Quote: 0
Read: Download Dissertation

Abstract


Polyphosphoester （PPE） is a class of biodegradable polymers with repeatedphosphoester bonds in the backbone. Due to the pentavalency of the phosphorous atomsin main chain, the pendant groups in PPE can be readily modified functionally andallowed the conjugation of bioactive molecules, resulting in all kinds of functionalpolyphosphoesters. Meanwhile, considered the properties of biocompatibility, cellularaffinity and capability of cell membrane permeability, PPE has gained more and moreattentions in biomedical applications.This dissertation is part of the National Natural Science Foundation of China“Design and Research of Functional Polymer Carriers based on Phosphoester（21074078）”. We designed to prepare a kind of amphiphilic polyesters with acryloyl inpendant groups of polyphosphoester. The polyesters would have good biocompatibility,full biodegradability and multifunctional modification. Both Michael-type additionreaction and thiol-ene reaction methods were utilized to modify the pendant groups ofthe polyesters. A series of biodegradable copolyesters with various functionalizedpendant groups were synthesized. The chemical structures and properties of thesecopolyesters were characterized. In addition, these copolyesters were further used asdrug delivery carries, and their biophysical properties were evaluated.The main contents and conclusions of this dissertation are summarized in threeparts:（1） Preparing cyclic phosphoester monomer [2-（2-oxo-1,3,2-dioxaphospholoyloxy）ethyl acrylate]（OPEA） with acryloyl in pendant group.Poly（ε-caprolactone）（PCL-OH） with hydroxyl group in the end of the chain wasutilized as macroinitiator and Sn（Oct）2was used as the catalyst. The parent diblockcopolymer PCL-b-POPEA was synthesized via ring-opening polymerization （ROP）. Therefore, the diblock copolymer had good biocompatibility and full biodegradability.In this work, we firstly introduced carbon carbon double bond （C=C） intopolyphosphoester segment, and then the carbon carbon double bond could further reactwith mercaptans via Michael-type addition reaction, resulting in a series offunctionalized block copolymers bearing diverse side groups （e.g. hydroxyl, carboxyl,amine, and amino acid）. The chemical structures of these block copolymers werecharacterized by NMR spectroscopy (1H NMR,13C NMR and31P NMR), gelpermeation chromatography （GPC）, and fourier transform infrared spectrometer （FT-IR）.In vitro cytotoxicity test by3-（4,5）-dimethylthiahiazo （-z-y1）-3,5-di-phenytetrazoliumromide （MTT） assay indicated that all the copolyesters possessed goodbiocompatibility, which measured up to the expected results.（2） Discussions of self-assembly behaviors of amphiphilic block copolymersPCL-b-POPEA in aqueous solution. The block copolymers assembled micellarnanoparticles with PCL as nucleus and POPEA as shell materials. The morphology, sizeand size distribution of the self-assembly nanoparticles of PCL-b-POPEA blockcopolymers were determined by transmission electron microscopy （TEM） andhigh-performance particle size instrument （HPPS）. Due to the good biocompatibilityand full biodegradability, the micellar nanoparticles were used as drug delivery carries.Initial drug loading and release studies using Doxorubicin （DOX） as a model drugdemonstrated a faster release in the presence of phosphodiesterase I as compared to thesystem without enzyme. Moreover, it was found that DOX-loaded nanoparticlesdisplayed higher inhibition to KB cells proliferation in comparison with DOX in freeform.（3） Random copolymers P（CL-co-OPEA） with acryloyl group were synthesizedvia ROP by mixed monomers of ε-caprolactone （ε-CL） and cyclic phosphoestermonomer OPEA. Benzyl alcohol was used as initiator and Sn（Oct）2was used as thecatalyst. Carboxyl groups were introduced to pendant groups of the random copolymersby thiol-ene reaction. Then galactosamine can be further conjugated topolyphosphoester segment of the random copolymer by the amidation reaction. NMRand GPC analyzed the chemical structures of these random copolymers. It was proved by1H NMR spectroscopy that carboxyl groups appeared in the pendant groups in thepolyphosphoester segment and the conjugation with amino of galactosamine. As a result,this kind of random copolymers would self-assemble into micellar nanoparticles andtarget to cancer cells.

Related Dissertations

  1. Synthesis of Functional Block Copolymer of Polyphosphoester and Their Functionlization,O631.3
  2. Preparation of Polyphosphoester/β-TCP Based Bone Repair Materials and Biomineralization in Vitro,R318.08
  3. Research Sulphate Control in Anaerobic Biotreatment Penicillin Wastewater,X703
  4. Study on the Enhancement of Biodegradability of Dyeing and Printing Wastewater by Anaerobic Baffled Reactor,X703.1
  5. Research on Heavy Oil Sewage by Hydrolysis Acidification-MBR,X703
  6. Research on the Toxicity, Bioactivity and Biodegradability of Common Ionic Liquids,X703
  7. The Study of Penicillin Wastewater by EGSB Reactor Treatment,X703
  8. Study on the Ondansetron Hydrochloride Intelligent Thermoresponsive Gels Controlled Nasal Mucosal Drug Delivery System,R94
  9. Synthesis and properties of new functionalized graphene oxide drug carriers,TQ460.4
  10. The Study of Glibenclamide Solid Self-Microemulsifying Capsule,R944
  11. Study on the Intelligent Thermosensitive Gel Nasal Mucosal Drug Delivery Systems of Breviscapine,R94
  12. Study on Intelligent Drug Delivery System of Light Sensitive Hydrogel Loaded Kojic Dipalmitate,R943
  13. Study on Intelligent Drug Delivery System of pH Sensitive Hydrogel Loaded Carvedilol,R943
  14. Study on an Immediate/Sustained Biphasic Delivery System of Clenbuterol Hydrochloride,R94
  15. Studies on the Cisplatin-Loaded Nano-Carbon,R94
  16. Study on the Thermosensitive Gel of Dextromethorphan Hydrobromide for Intranasal Administration,R94
  17. Theory of Ultrasound Micro/nano Particle Manipulation and Research of Acoustic Field Design,R319
  18. Synthesis, Characterization and Application of Thermo-sensitive Poly (N-acryloyl Glycinates),O631.3
  19. Study on Self-Assembly Morphology Evolution of Block Copolyer by AFM,O631.3
  20. Synthesis of a Novel Well-defined Amphiphilic Block Copolymers and Preparation of Its Anti-tumor Prodrug,TQ460.1
  21. Synthesis and Characterization of Flower-like NiO Nanoarchitectures with Nanosheets,TB383.1

CLC: > Mathematical sciences and chemical > Chemistry > Polymer chemistry ( polymer ) > Polymer physics and physical chemistry of polymers > The chemical nature of polymers
© 2012 www.DissertationTopic.Net  Mobile