Researcher: Hocaoğlu, İbrahim
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Hocaoğlu, İbrahim
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Publication Metadata only Apoptosis induction by 2-mercaptopropionic acid (2-MPA)-coated silver sulfide QD in human A549 cells(Elsevier, 2017) Vardar, Deniz Özkan; Aydın, Sevtap; Başaran, Nurşen; N/A; Department of Chemistry; Department of Chemistry; Hocaoğlu, İbrahim; Acar, Havva Funda Yağcı; PhD Student; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; N/A; 178902N/APublication Metadata only Genotoxicity of 2-mercaptopropionic acid-coated silver sulfide quantum dot(Elsevier, 2015) Vardar, Deniz Özkan; Aydın, Sevtap; Başaran, Nurşen; N/A; Department of Chemistry; Department of Chemistry; Hocaoğlu, İbrahim; Acar, Havva Funda Yağcı; PhD Student; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; N/A; 178902N/APublication Metadata only Cyto/hemocompatible magnetic hybrid nanoparticles (ag2s-fe3o4) with luminescence in the near-infrared region as promising theranostic materials(Elsevier, 2015) Grandfils, Christian; Ojea-Jimenez, Isaac; Rossi, Francois; Dogan, Nurcan; Department of Physics; N/A; Department of Chemistry; Department of Chemistry; N/A; Department of Physics; Department of Chemistry; Kiraz, Alper; Hocaoğlu, İbrahim; Aşık, Didar; Acar, Havva Funda Yağcı; Ulusoy, Gülen; Faculty Member; PhD Student; Master Student; Faculty Member; N/A; College of Sciences; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; N/A; 22542; N/A; N/A; 178902; N/ASmall hybrid nanoparticles composed of highly biocompatible Ag2S quantum dots (QD) emitting in the near-infrared region and superparamagnetic iron oxide (SPION) are produced in a simple extraction method utilizing ligand exchange mechanism. Hybrid nanoparticles luminesce at the same wavelength as the parent QD, therefore an array of hybrid nanoparticles with emission between 840 and 912 nm were easily produced. Such hybrid structures have (1) strong luminescence in the medical imaging window eliminating the autofluoresence of cells as effective optical probes, (2) strong magnetic response for magnetic targeting and (3) good cyto/hemocompatibility. An interesting size dependent cytotoxicity behavior was observed in HeLa and NIH/3T3 cell lines: smallest particles are internalized significantly more by both of the cell lines, yet showed almost no significant cytotoxicity in HeLa between 10 and 25 mu g/mL Ag concentration but were most toxic in NIH/3T3 cells. Cell internalization and hence the cytotoxicity enhanced when cells were incubated with the hybrid nanoparticles under magnetic field, especially with the hybrid nanoparticles containing larger amounts of SPION in the hybrid composition. These results prove them as effective optical imaging agents and magnetic delivery vehicles. Combined with the known advantages of SPIONs as a contrast agent in MRI, these particles are a step forward for new theranostics for multimode imaging and magnetic targeting.Publication Metadata only Epigenetic changes of 2-mercaptopropionic acid (2-MPA)-coated silver sulfide quantum dot in human cervical carcinoma cells(Elsevier, 2016) Vardar, Deniz Özkan; Aydın, Sevtap; Başaran, Nurşen; N/A; Department of Chemistry; Department of Chemistry; Hocaoğlu, İbrahim; Acar, Havva Funda Yağcı; PhD Student; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; N/A; 178902N/APublication Open Access Development of highly luminescent and cytocompatible near-IR-emitting aqueous Ag2S quantum dots(Royal Society of Chemistry (RSC), 2012) Çizmeciyan, M. Natali; Erdem, Rengin; Özen, Can; Kurt, Adnan; N/A; Department of Physics; Department of Chemistry; Department of Physics; Department of Chemistry; Hocaoğlu, İbrahim; Sennaroğlu, Alphan; Acar, Havva Funda Yağcı; PhD Student; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; N/A; 23851; 178902Colloidally stable and highly luminescent near-IR emitting Ag2S quantum dots (NIRQDs) were prepared by a very simple aqueous method using 2-mercaptopropionic acid (2MPA) as a coating. Emission of Ag2S-2MPA NIRQDs can be tuned between 780 and 950 nm. These NIRQDs have photoluminescence quantum yields (PLQY) around 7–39% and exhibit excellent cytocompatibility even at 600 mg mL 1 in NIH/3T3 cells. With such improved properties, Ag2S-2MPA NIRQDs have a great potential in practical bio-applications.Publication Open Access Highly luminescent and cytocompatible cationic Ag2S NIR-emitting quantum dots for optical imaging and gene transfection(Royal Society of Chemistry (RSC), 2015) Ozturk, Deniz Gulfem; Gozuacik, Devrim; Department of Chemistry; Department of Physics; Department of Chemistry; Department of Physics; Duman, Fatma Demir; Hocaoğlu, İbrahim; Kiraz, Alper; Acar, Havva Funda Yağcı; PhD Student; PhD Student; Faculty Member; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Sciences; N/A; N/A; 22542; 178902The development of non-toxic theranostic nanoparticles capable of delivering a therapeutic cargo and providing a means for diagnosis is one of the most challenging tasks in nano-biotechnology. Gene therapy is a very important mode of therapy and polyethyleneimine (PEI) is one of the most successful vehicles for gene transfection, yet poses significant toxicity. Optical imaging utilizing quantum dots is one of the newer but fast growing diagnostic modalities, which requires non-toxic, highly luminescent materials, preferentially active in the near infrared region. Ag2S NIRQDs fit to this profile perfectly. Here, we demonstrate the aqueous synthesis of cationic Ag2S NIRQDs with a mixed coating of 2-mercaptopropionic acid (2MPA) and PEI (branched, 25 kDa), which are highly luminescent in the NIR-I window (lambda(em) = 810-840 nm) as new theranostic nanoparticles. Synergistic stabilization of the QD surface via the simultaneous use of a small molecule and a polymeric material provided the highest quantum yield, 150% (with respect to LDS 798 at pH 7.4), reported in the literature for Ag2S. These cationic particles show a dramatic improvement in cytocompatibility even without PEGylation, a strong optical signal easily detected by confocal laser microscopy and effective conjugation and transfection of the green fluorescence protein plasmid (pGFP) to HeLa and MCF-7 cell lines (40% efficiency). Overall, these Ag2S NIRQDs show great potential as new theranostics.Publication Open Access Emission tunable, cyto/hemocompatible, near-IR-emitting Ag2S quantum dots by aqueous decomposition of DMSA(Royal Society of Chemistry (RSC), 2014) Sevrin, Chantal; Department of Chemistry; Department of Physics; Department of Chemistry; Department of Physics; Birer, Özgür; Hocaoğlu, İbrahim; Kiraz, Alper; Acar, Havva Funda Yağcı; Duman, Fatma Demir; Researcher; PhD Student; Faculty Member; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); College of Engineering; College of Sciences; Graduate School of Sciences and Engineering; N/A; N/A; N/A; 22542; N/A; 178902Size tunable aqueous Ag2S quantum dots emitting in the near-infrared region were synthesized through decomposition of meso-2,3-dimercaptosuccinic acid (DMSA) in water. The resulting NIR QDs are highly cyto- and hemocompatible, have quantum yields as high as 6.5% and are effective optical imaging agents based on in vitro evaluation.