Synthesis and Chatacterization of Biocompatible,PEG-Derived Comb Copolymers for Drug Delivery System Application
| Autor: | Huei Fung Chang, 常慧芳 |
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| Rok vydání: | 1996 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 84 The relatively low water solubility of a hydrophobic druglimits its use in pharmaceutical application.Polymeric vehicleswhich can effectively incorporate and deliver such drugs in circulation are of great intest. Amphiphilic copolymers, composed of both the hydrophilic and hydrophobic segments,form micellar structures through the association of the hydrophobic segments in aqueous solution.Hydrophobic cores of polymeric micelles to achieve sustained drug release and such a system shows great potential a vehicle for the drug delivery system, especially in cancer chemotherapy. The comb copolymer is capable of forming polymeric micelles in the aqueous phase. PEG molecules which are present at the surface of micelles cab prohibt protein adsorption and decrease the RES uptake.In this study,comb copolymers comprising both hydrophilic PEG side chains and hydrophobic stearyl side chains were prepared. First, precursor polymers containing acid chloride groups were obtained by radical copolymerization of acryloyl chloride and stearyl methacrylate.Comb-shaped polymers were then prepared by grafting of poly(ethylene glycol)monomethyl ethers containing acid chloride groups by condensation reaction. The polymers were subsequently purified andtheir characteristics uated by H- NMR and IR. The degree of grafting was found to beabout 4.3~12 grafts/100 monomer units. Molecular weights of polymers and the physical properities of the micellar solution of the micellar solution of comb copolymers such as aggregation numbers, molecular weight,CMC,particles size and particle size stability, were characterized by static and dynamic light scattering methods. All polymers showed low critical mlcelle concentration( ~2mg/L).The amount of htdrophobic molecules which an be incorporated into the micelles and released from micelles were investigated by UV spectroscopy using pyrene as a drug model. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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