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    Öğe
    Exploiting ionisable nature of PEtOx-co-PEI to prepare pH sensitive, doxorubicin-loaded micelles
    (Taylor & Francis Ltd, 2020) Ozturk, Naile; Kara, Asli; Gulyuz, Sevgi; Ozkose, Umut Ugur; Tasdelen, Mehmet Atilla; Bozkir, Asuman; Vural, Imran
    Aims This study was conducted to evaluate block copolymers containing two different poly(ethyleneimine) (PEI) amounts, as new pH-sensitive micellar delivery systems for doxorubicin. Methods Micelles were prepared with block copolymers consisting of poly(2-ethyl-2-oxazoline)-co-poly(ethyleneimine) (PEtOx-co-PEI) and poly(epsilon-caprolactone) (PCL) as hydrophilic and hydrophobic blocks, respectively. Doxorubicin loading, micelle size, pH-dependent drug release, and in vitro cytotoxicity on MCF-7 cells were investigated. Results The average size of drug-loaded micelles was under 100 nm and drug loading was between 10.7% and 48.3% (w/w). pH-sensitive drug release was more pronounced (84.7% and 68.9% (w/w) of drug was released at pH 5.0 and pH 7.4, respectively) for the micelles of the copolymer with the lowest PEI amount. The cell viability of doxorubicin-loaded micelles which were prepared by the copolymer with the lowest PEI amount was 28-33% at 72 h. Conclusions PEtOx-co-PEI-b-PCL micelles of this copolymer were found to be stable and effective pH-sensitive nano-sized carriers for doxorubicin delivery.
  • [ X ]
    Öğe
    Poly(2-ethyl-2-oxazoline-co-ethyleneimine)-block-poly(epsilon-caprolactone) based micelles: synthesis, characterization, peptide conjugation and cytotoxic activity
    (Royal Soc Chemistry, 2021) Gulyuz, Sevgi; Ozkose, Umut Ugur; Khalily, Melek Parlak; Kesici, Mehmet Seckin; Kocak, Polen; Bolat, Zeynep Busra; Yilmaz, Ozgur
    Here we present self-assembled polymeric micelles as potential delivery systems for therapeutic agents with highly tunable properties. The major goal of this study is to design breast and prostate cancer specific targeting peptide modified PEtOx-co-PEI-b-PCL block copolymer based micelles as a targetable carrier system in cancer treatment. For this, a series of micelles based on poly(2-ethyl-2-oxazoline)-co-polyethyleneimine-block-poly(epsilon-caprolactone) [P(EtOx-co-EI)-b-PCL] copolymers with two different proportions of PEI (30% and 60% hydrolysis degrees of PEtOx) were successfully prepared. The block copolymers were synthesized using a combination of living cationic ring-opening polymerization and a copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction. Then, peptide 18 and peptide 563 were conjugated to P(EtOx-co-EI)-b-PCL through a thiol-ene click-type reaction to obtain the desired tumor-targeting. The structural properties of the copolymers were confirmed by H-1 NMR, FT-IR, UV-Vis spectrometry and GPC. Peptide and non-peptide-conjugated micelles with particle sizes between 82 +/- 0.6 and 170 +/- 10.7 nm were obtained by self-assembly with two different chain lengths of PEI blocks. The micelles containing the 60% PEI block showed increased zeta potential values. The cytotoxicity of the copolymers was evaluated under in vitro conditions. Overall, our results indicate that the micelles prepared with peptide-conjugated block copolymers can be used as potential nanocarriers for targeted therapeutic delivery systems.