Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
Browse
3 results
Search Results
Now showing 1 - 3 of 3
Article Citation - Scopus: 1A Diaminoethane Motif Bearing Low Molecular Weight Polymer as a New Nucleic Acid Delivery Agent(Elsevier, 2021) Zelcak, Aykut; Ünal, Yağmur Ceren; Meşe, Gülistan; Bulmuş, VolgaAmong polymer-based gene delivery systems, poly(ethylene imine) (PEI) stands out as an effective polycation. However, the toxic effects of PEI especially at higher molecular weights limit its usage. Although the effects of PEI's architecture and molecular weight on gene delivery is controversial in literature, low molecular weight PEI appears to be efficient at transfection while having lower toxicity. Herein, as an alternative to low molecular weight, linear PEI, a methacrylate polymer bearing diamimoethane motifs, poly(2-((2-aminoethyl)amino)ethyl methacrylate) (P(AEAEMA)), was evaluated in vitro as a new nucleic acid delivery agent. P(AEAEMA) (8 kDa) showed low toxicity on Skov-3-luc and NIH/3T3 cell lines at polymer concentrations where PEI (8 kDa) was highly toxic. P(AEAEMA) could efficiently form complexes with siRNA at an N/P ratio of 2 as shown by gel electrophoresis. The diameter of P(AEAEMA)-siRNA complexes was found to be significantly lower than PEIsiRNA complexes almost at all tested N/P ratios. P(AEAEMA) could improve the stability of siRNA in serum containing media by protecting the siRNA against serum nucleases. siRNA and pDNA transfection efficiency of P (AEAEMA) on luciferase expressing Skov-3-luc cell line and HEK 293T cell line, respectively was found to be comparable to well-known nucleic acid carrier, PEI. The transfection efficiency of both P(AEAEMA) and PEI was found to be cell-type-dependent. None of the polymers were able to transfect MDA-MB-231 cells with siRNA or pDNA.Article Citation - WoS: 5Citation - Scopus: 6Efficient Synthesis of Crgd Functionalized Polymers as Building Blocks of Targeted Drug Delivery Systems(Elsevier Ltd., 2018) Thankappan, Hajeeth; Zelçak, Aykut; Taykoz, Damla; Bulmuş, VolgaSynthetic peptides with cyclic arginine-glycine-aspartate motif (cRGD) play an important role in cell recognition and cell adhesion. cRGD-decorated soluble polymers and polymeric nanoparticles have been increasingly used for cell-specific delivery of antitumor drugs. While the significance of cRGD modification for tumor cell-specific targeting of polymeric carriers is well-accepted, straightforward procedures ensuring the fidelity of cRGD modification of polymeric systems are still lacking. Herein, we have reported an in-situ polymerization approach for synthesis of cRGD-end-functionalized well-defined polymers as potential building blocks of targeted drug delivery systems. A new cRGD peptide functionalized RAFT agent was synthesized as confirmed by MALDI-TOF and 1H NMR spectroscopy. The ability of this RAFT agent to control polymerizations was then tested using two different monomers oligoethyleneglycol acrylate and t-butyl methacrylate. The RAFT-controlled character of polymerizations and the living characteristic of the synthesized polymers were investigated through a series of kinetic experiments. The cytotoxicity and targeting capability of cRGD-functionalized OEGA polymers were investigated using cell lines expressing αvβ3 integrins at varying extents.Article Citation - WoS: 36Citation - Scopus: 38Effect of Molecular Architecture on Cell Interactions and Stealth Properties of Peg(American Chemical Society, 2017) Özer, İmran; Tomak, Aysel; Zareie, Hadi M.; Baran, Yusuf; Bulmuş, VolgaPEGylation, covalent attachment of PEG to therapeutic biomolecules, in which suboptimal pharmacokinetic profiles limiting their therapeutic utility are of concern, is a widely applied technology. However, this technology has been challenged by reduced bioactivity of biomolecules upon PEGylation and immunogenicity of PEG triggering immune response and abrogating clinical efficacy, which collectively necessitate development of stealth polymer alternatives. Here we demonstrate that comb-shape poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA), a stealth polymer alternative, has a more compact structure than PEG and self-organize into nanoparticles in a molecular weight dependent manner. Most notably, we show that comb-shape POEGMA promotes significantly higher cellular uptake and exhibits less steric hindrance imposed on the conjugated biomolecule than PEG. Collectively, comb-shape POEGMA offers a versatile alternative to PEG for stealth polymer-biomolecule conjugation applications.
