https://hdl.handle.net/20.500.12960/21 2026-05-24T23:44:54Z https://hdl.handle.net/20.500.12960/1792 Engineering Two-in-One Nanoparticles for Simultaneous Delivery of Graphene Quantum Dot and Pemetrexed Öz, Umut Can; Küçüktürkmen, Berrin; Gómez, I. Jénnifer; Elsherbeny, Amr; İpek Tekneci, Seda; Eşim, Özgür; Göksever, Selin; Özköse, Umut Uğur; Gülyüz, Sevgi; Bazán-Cobelo, Claudia The simultaneous delivery of therapeutic agents and imaging probes using polymeric nanoparticles (NPs) has gained significant attention for cancer treatment. In this work, we developed a multifunctional nanocarrier system composed of an amphiphilic block copolymer, poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) (PEtOx-b-PCL), and dimethyldidodecylammonium bromide (DDAB), for the codelivery of the chemotherapeutic drug pemetrexed (PMT) and nitrogen- or sulfur-doped graphene quantum dots (N-GQDs or S-GQDs) as fluorescent probes. Critical formulation parameters were optimized using a central composite design (CCD). The optimized NPs exhibited favorable physicochemical properties, including positive surface charge (6–8 mV), hydrodynamic diameters of ∼140 nm, and high encapsulation efficiency for both PMT (46–56%) and GQDs (>98%). In vitro assays revealed that PMT-loaded nanoparticles (NPs) significantly enhanced cytotoxicity against MCF-7 cells. At a concentration of 2 ppm after 72 h, N-PMT NPs and S-PMT NPs inhibited cell proliferation by 50.7% and 53.8%, respectively, compared to 37.8% inhibition with free PMT at the same dose. Confocal microscopy confirmed efficient intracellular uptake and strong fluorescence signals, supporting their potential for bioimaging. Collectively, these results demonstrate that this two-in-one nanocarrier system significantly enhances chemotherapeutic efficacy while enabling real-time imaging, establishing a promising platform for drug delivery and noninvasive treatment monitoring in cancer nanomedicine. https://hdl.handle.net/20.500.12960/1764 The use of graphene nanoplatelet-embedded PA-6 nanofibres to remove turbidity from water Zembat, Ahmet Alp; Gezmis-Yavuz, Elifnur; Köseoğlu-İmer, Derya Y.; Cansoy, C. Elif The global challenge of providing clean water at an affordable cost has led to the need for the development of low-cost and non-toxic materials for the treatment and recycling of waste water. Nanofibres have emerged as a promising solution due to their superior properties. To this end, composite polyamide-6 (PA-6) nanofibres embedded with graphene nanoplatelets (GNPs) were prepared by electrospinning. The study investigated the effect of the ratio of GNPs, which ranged from 0.1 to 1.0 wt.%, on the mechanical properties of nanofibres and the removal of turbidity. The results showed that PA-6 nanofibres with 0.5 wt.% GNP exhibited enhanced mechanical properties, and increasing the GNP ratio led to lower turbidity values. To the best of our knowledge, GNP-embedded PA-6 nanofibres have not been used for turbidity removal before, and these filter materials are promising due to their excellent fibre structure, mechanical strength, and high level of turbidity removal. 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12960/1763 Fabrication of electrospun graphene-oxide embedded polyacrylonitrile composite nanofibers for air filtration Demir, Gamze; Gezmiş-Yavuz, Elifnur; Zembat, Ahmet Alp; Koseoglu-Imer, Derya Y.; Cansoy, C. Elif In this study, polyacrylonitrile-graphene oxide (PAN/GO) nanofiber composite nanofibers were prepared with varying GO ratios between 0.1 and 0.5 wt% by electrospinning technique. The fiber diameter of bare PAN was increased from 184 ± 40 nm to 314.5 ± 20.42 nm with the rise of GO ratio to 0.5 wt%. Accordingly, an improvement in the mechanical strength of bare PAN nanofibers was also observed. While the modulus of elasticity value for bare PAN nanofiber was calculated as 1.75 ± 0.2 MPa, this value was found to be 6.55 ± 0.13 MPa when the GO ratio was 0.5 wt%. Similarly, tensile strength of bare PAN nanofiber increased from 0.377 to 0.550 MPa and yield strength from 0.17 to 0.35 MPa at 0.5 wt% GO ratio. When water vapor transmission values of nanofibers were calculated, it was found that with the increase of GO ratio, the nanofibers became more hydrophilic and water vapor was adsorbed more on the filter surface, resulting in a decrease in water vapor transmission values down to 176.70 g/m2h. The PAN-GO nanofibers are promising candidates for the air filter materials due to their excellent mechanical properties, low cost and non-toxicity. 2025-01-01T00:00:00Z https://hdl.handle.net/20.500.12960/1759 Delivery of BikDD proapoptotic gene in Peptide-18-targeted Poly(2-oxazoline)-DOPE nanoliposomes for breast cancer models Bolat, Zeynep Büşra; Nezir, Ayça Ece; Saka, Ongun Mehmet; Zemheri, Itır Ebru; Gülyüz, Sevgi; Özköse, Umut Uğur; Yılmaz, Özgür; Bozkır, Asuman; Telci, Dilek; Şahin, Fikrettin Breast cancer is one of the most common cancers and a significant cause of death in females worldwide. For effective breast cancer treatment, using systems with a promising delivery of anticancer agents is an important strategy. Peptide 18 (P18), a tumor-homing peptide, shows a high binding affinity toward breast cancer cells. Nanoliposomes are known to have enhanced accumulation ability in tumors with longer systemic circulation. In this study, Poly (2-ethyl-2-oxazoline) (PEtOx) polymers conjugated with DOPE are used to prepare PEtOx-DOPE nanoliposomes. BikDD, a mutant form of the Bik gene and a member of the BH3-only proapoptotic genes, mimics the constitutively phosphorylated form of the gene. To the best of our knowledge, this study presents a novel approach by investigating P18-conjugated PEtOx-DOPE nanoliposomes (P18-PEtOx-DOPE) for the targeted delivery of BikDD to the AU565 breast cancer model. A site-directed mutated BikDD was loaded into P18-PEtOx-DOPE nanoliposomes, and the targeted drug delivery system was assessed in in vitro and in vivo breast cancer models for efficiency, safety, and efficacy. The increased Bik mRNA expression levels in AU565 cells suggest a high effectiveness of the targeting PEtOx-DOPE nanoliposomes. Following the in vitro studies, the delivery of BikDD by P18-PEtOx-DOPE nanoliposomes was analyzed in CD-1 nude mice models. The animal study showed no significant difference in the tumor volume of the CD-1 nude mice treated with P18-PEtOx-DOPE-BikDD nanoliposomes compared to the free delivery of BikDD. Our preclinical studies suggest that P18-PEtOx-DOPE-BikDD nanoliposomes may be promising gene carriers for targeted breast cancer therapy. Thus, further studies should be carried out to determine the prolonged use of this drug delivery system in breast cancer therapy. 2024-01-01T00:00:00Z