Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
3 results
Search Results
Now showing 1 - 3 of 3
Article Citation - WoS: 12Citation - Scopus: 12Peg and Peg-Peptide Based Doxorubicin Delivery Systems Containing Hydrazone Bond(Springer Verlag, 2018) Balcı, Beste; Top, AybenmPEG and mPEG-peptide based drug delivery systems were prepared by conjugating doxorubicin (DOX) to these carrier molecules via hydrazone bond. The peptide, AT1, with a sequence of CG3H6G3E served as mPEG and doxorubicin attachment site. Histidines were incorporated to the sequence to improve pH responsiveness of the carrier molecule. Hydrodynamic diameters (mean sizes) of mPEG-based drug delivery system (mPEG-HYD-DOX) were measured as 9 ± 0.5 and 7 ± 0.5 nm at pH 7.4 and pH 5.0, respectively. Mean size of the aggregates of the peptide containing drug delivery system, mPEG-AT1-DOX, was determined as 12 ± 2 nm at neutral pH. At pH 5.0, on the other hand, mPEG-AT1-DOX exhibited a size distribution between 20 and 100 nm centered at about 40 nm. Comparison of % DOX release values of the drug delivery systems obtained at pH 7.4 and pH 5.0 indicated that mPEG-AT1-DOX has enhanced pH sensitivity. DOX equivalent absolute IC50 values were obtained as 0.96 ± 0.51, 21.9 ± 5.9, and 5.55 ± 0.75 μg/mL for free DOX, mPEG-HYD-DOX, and mPEG-AT1-DOX, respectively. Considering more pronounced pH sensitivity and cytotoxicity of mPEG-AT1-DOX, the use of both pH responsive functional groups and acid cleavable chemical bond between the carrier molecule and drug can be a promising approach in the design of drug delivery systems for cancer therapy.Article Citation - WoS: 42Citation - Scopus: 47Ph Responsive Glycopolymer Nanoparticles for Targeted Delivery of Anti-Cancer Drugs(Royal Society of Chemistry, 2018) Yılmaz, Gökhan; Güler, Emine; Geyik, Caner; Demir, Bilal; Özkan, Melek; Odacı Demirkol, Dilek; Özçelik, Serdar; Timur, Suna; Becer, C. RemziOver the past decade, there has been a great deal of interest in the integration of nanotechnology and carbohydrates. The advances in glyconanotechnology have allowed the creation of different bioactive glyconanostructures for different types of medical applications, especially for drug delivery and release systems. Therefore, the use of more efficient biocompatible nanocarriers with high loading capacity, low overall toxicity and receptor-mediated endocytosis specificity is still in focus for the enhancement of the therapeutic effect. Conjugation of sugar derivatives onto gold nanoparticles presents unique properties that include a wide array of assembling models and size-related electronic, magnetic and optical properties. Here, pH-responsive drug-conjugated glycopolymer-coated gold nanoparticles were prepared by functionalization of gold nanoparticles with thiol-terminated glycopolymers and then subsequent conjugation of doxorubicin (DOX). Among the four different glycopolymers, their drug release, physicochemical characterization (spectroscopy, particle size and surface charge) and in vitro bioapplications with four different cell lines were compared. As a result, pH-sensitive drug delivery via sugar-coated AuNPs was performed thanks to hydrazone linkages between glycopolymers and DOX. Comparative viability tests also demonstrated the efficiency of glycopolymer-DOX conjugates by fluorescence cell imaging. The obtained results reveal that AuNP homoglycopolymer DOX conjugates (P4D) have significant potential, especially in human neuroblastoma cells in comparison to cervical cancer cells and lung cancer cells.Article Citation - WoS: 12Citation - Scopus: 12Controlling Assembly of Helical Polypeptides Via Pegylation Strategies(Royal Society of Chemistry, 2011) Top, Ayben; Zhong, Sheng; Yan, Congqi; Roberts, Christopher J.; Pochan, Darrin J.; Kiick, Kristi L.Recent studies in our laboratories have demonstrated that a helical polypeptide (17H6), equipped with a histidine tag and a helical alanine-rich, glutamic-acid-containing domain, exhibits pH-responsive assembly behavior useful in the production of polymorphological nanostructures. In this study, the histidine tag in these polypeptides was replaced by polyethylene glycol (PEG) with different molecular masses (5 kDa, or 10 kDa), and the self-association behavior of 17H6 and the PEGylated conjugates was characterized via dynamic light scattering (DLS), small angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). DLS experiments illustrated that the polypeptide and its PEG-conjugates undergo reversible assembly under acidic conditions, suggesting that the aggregation state of the polypeptide and the conjugates is controlled by the charged state of the glutamic acid residues. Nanoscale aggregates were detected at polypeptide/conjugate concentrations as low as 20 μM (∼0.3-0.5 mg ml -1) at physiological and ambient temperatures. Scattering and microscopy results showed that the size, the aggregation number, and the morphology of the aggregates can be tuned by the size and the nature of the hydrophilic tag. This tunable nature of the morphology of the aggregates, along with their low critical aggregation concentration, suggests that PEG-alanine-rich polypeptide conjugates may be useful as drug delivery vehicles in which the alanine-rich block serves as a drug attachment domain.