Synthesis of cationic star polymers via RAFT polymerization için kapak resmi
Synthesis of cationic star polymers via RAFT polymerization
Başlık:
Synthesis of cationic star polymers via RAFT polymerization
Yazar:
Dursun, Gürbüz, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xiii, 89 leaves: illustrarions, charts;+ 1 computer laser optical disc.
Özet:
The aim of this master thesis is to synthesize cleavable, core-crosslinked, cationic, new star polymers as potential siRNA carrier systems. The core-crosslinked star polymers of aminoethyl aminoethyl methacrylate (AEAEMA) monomer were synthesized for the first time in the literature. A crosslinker, potentially cleavable in cell cytosol, bis(2-methacryloyl) oxyethyl disulfide, and AEAEMA monomer with Boc-protection groups (BocAEAEMA) were polymerized using P(OEGMA) macroRAFT agents (5 kDa or 10 kDa). The polymerization kinetics revealed a linear increase in ([M]0/[M]) with increasing polymerization time, indicating the RAFT-controlled polymerization mechanism. The incorporation of arms into star structure completed between 2 and 8 hours of polymerization, leading to star formation yields of approx. 55%. Star polymers with narrow PDI values (between 1.52 and 1.80) and controllable molecular weights (between 116 kDa and 620 kDa) were synthesized using a P(OEGMA) macroRAFT agent of 10 kDa. Increasing crosslinker to macroRAFT agent ratio led to increase in crosslinker conversion and decrease in BocAEAEMA conversion. Increasing BocAEAEMA to macroRAFT agent ratio had the exact opposite effect. The use of a macroRAFT agent of 5 kDa led to a dramatic increase in molecular weight (up to 3370 kDa). The hydrodynamic sizes (Dh) of water soluble, cationic star polymers, obtained after deprotection of amino groups, dropped from 2-36 nm to 1-18 nm after treatment with a reducing agent in water, indicating the cleavable nature of the star structures. Among the star polymers tested, the polymer having 7 arms of POEGMA (10 kDa) and a degree of polymerization of AEAEMA (DPAEAEMA) of 70 efficiently complexed with siRNA at a nitrogen/phosphate ratio of 1. While this polymer showed higher cytotoxicity, when compared with other star polymers tested, all polymers were significantly less toxic, compared to branched PEI, a golden standard cationic polymer for siRNA delivery.
Yazar Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Biotechnology.

İzmir Institute of Technology: Biotechnology--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.
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