Researcher:
Almammadov, Toghrul

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Researcher

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Toghrul

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Almammadov

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Almammadov, Toghrul

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2019 - 201922020 - 20239

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Now showing 1 - 10 of 12
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    Selective monitoring and treatment of neuroblastoma cells with hydrogen sulfide activatable phototheranostic agent
    (Elsevier, 2023) Kepil, Dilay; Elmazoglu, Zubeyir; Ozogul, Naz; Gunbas, Gorkem; N/A; Department of Chemistry; N/A; Department of Chemistry; Dırak, Musa; Almammadov, Toghrul; Çetin, Sultan; Kölemen, Safacan; PhD Student; Researcher; PhD Student; Faculty Member; Department of Chemistry; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; College of Sciences; Graduate School of Sciences and Engineering; College of Sciences; N/A; N/A; N/A; 272051
    Activity-based photosensitizers (aPSs) are highly attractive as they offer improved selectivity and better therapeutic outcome in the scope of photodynamic therapy (PDT). Here, a hydrogen sulfide (H2S) responsive iodinated resorufin-based PS (RHS) was developed to treat neuroblastoma cancer cells selectively. RHS was shown to be a phototheranostic agent as it turned on its fluorescence signal and singlet oxygen (O-1(2)) generation capability after reacting with H2S. RHS exhibited remarkable sensitivity towards H2S and proved to be highly cytotoxic in H2S rich SH-SY5Y human neuroblastoma cells upon light irradiation. In contrast, no photocytotoxicity was observed in H2S deficient nonmalignant fibroblast L929 cells. RHS marks the first example of a resorufin-based H2S activatable photo-theranostic agent, which paves the way for effective treatment of neuroblastoma through PDT modality.
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    Directing chemiluminescent dioxetanes to mitochondria: a cationic luminophore enables in vitro and in vivo detection of cancer cells upon enzymatic activation
    (Elsevier B.V., 2023) Department of Chemistry; N/A; N/A; Department of Chemistry; N/A; N/A; N/A; N/A; N/A; Department of Chemistry; Gündüz, Hande; Acari, Alperen; Çetin, Sultan; Almammadov, Toghrul; Değirmenci, Nareg Pınarbaşı; Dırak, Musa; Cingöz, Ahmet; Kılıç, Eda; Önder, Tuğba Bağcı; Kölemen, Safacan; Researcher; Master Student; PhD Student; Researcher; PhD Student; PhD Student; Researcher; Master Student; Faculty Member; Faculty Member; Department of Chemistry; N/A; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; N/A; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); N/A; N/A; N/A; College of Sciences; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; College of Sciences; Graduate School of Health Sciences; Graduate School of Sciences and Engineering; N/A; Graduate School of Sciences and Engineering; School of Medicine; College of Sciences; 224496; N/A; N/A; N/A; N/A; N/A; N/A; N/A; 184359; 272051
    A mitochondrion targeted and leucine aminopeptidase (LAP) activatable 1,2-dioxatane based chemiluminescent probe (MCL) for detection of LAP activity in living cancer cells and tumor bearing mice was reported. MCL displayed a selective and sensitive turn-on response in aqueous solutions upon reacting with the LAP enzyme. In cell culture studies, a selective luminescence intensity increase was observed in cancer cell lines, suggesting that MCL can differentiate between cancer and normal cells and allows detection of varying endogenous LAP concentrations. Using fluorescence imaging with a commercial Mitotracker dye, MCL was also shown to localize mitochondria in cancer cell lines. Furthermore, MCL was used to image tumors in mice models. MCL marks not only the first ever example of a mitochondria targeted chemiluminescent probe, but also the first ever example of an organelle targeted 1,2-dioxetane derivative. © 2023 Elsevier B.V.
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    A hydrogen peroxide responsive resorufin-based phototheranostic agent for selective treatment of cancer cells
    (Elsevier Sci Ltd, 2021) Department of Chemistry; Department of Chemistry; Almammadov, Toghrul; Kölemen, Safacan; Researcher; Faculty Member; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Koç University Boron and Advanced Materials Application and Research Center (KUBAM) / Koç Üniversitesi Bor ve İleri Malzemeler Uygulama ve Araştırma Merkezi (KUBAM); College of Sciences; College of Sciences; N/A; 272051
    Enhanced selectivity towards cancer cells is one of the most essential features sought in new generation photodynamic therapy (PDT) agents in order to minimize the side effects on healthy cells and to improve the efficacy of the treatment. In this direction, one promising approach is to design activatable photosensitizers, which tend to stay in an OFF state and get activated only in cancer cells with tumor-associated stimuli. Based on this idea, herein we introduced a hydrogen peroxide (H2O2) activatable iodinated resorufin (RR-1) as a redshifted, water soluble and cancer cell selective photosensitizer. RR-1 exhibited high singlet oxygen quantum yield in aqueous solutions upon reacting with H2O2 and induced selective photocytotoxicity in colorectal (HCT116) and triple negative breast (MDA MB-231) cancer cells, which contain high level of reactive oxygen species (ROS). Additionally, fluorescence signal of the iodo-resorufin core was restored upon cleavage of the cage unit in these cancer cells. In contrast, very low photocytotoxicity and negligible fluorescence enhancement were observed in normal fibroblast (NIH-3T3) cells. RR-1 not only marks the first example of a H2O2 activatable resorufin-based photosensitizer but also represents the first ever resorufin-based theranostic agent. We anticipate that iodo-resorufin scaffold can be easily modified with different masking units towards realization of highly selective and efficient phototheranostic agents for treatment of various cancer cells.
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    A leucine aminopeptidase activatable photosensitizer for cancer cell selective photodynamic therapy action
    (Elsevier Sci Ltd, 2021) N/A; N/A; N/A; Department of Chemistry; N/A; Department of Physics; Department of Chemistry; Department of Chemistry; Arslan, Büşra; Bilici, Kübra; Demirci, Gözde; Almammadov, Toghrul; Khan, Minahil; Sennaroğlu, Alphan; Acar, Havva Funda Yağcı; Kölemen, Safacan; Master Student; PhD Student; Master Student; Researcher; PhD Student; Faculty Member; Faculty Member; Faculty Member; Department of Physics; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Boron and Advanced Materials Application and Research Center (KUBAM) / Koç Üniversitesi Bor ve İleri Malzemeler Uygulama ve Araştırma Merkezi (KUBAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; College of Sciences; N/A; N/A; N/A; N/A; N/A; 23851; 178902; 272051
    Activity based photosensitizers (PS) continue to attract great attention as they enable selective photodynamic therapy action on cancer cells while sparing normal cells even under light irradiation. Sensitivity to specific enzymes that are differentially overexpressed in cancer cells is crucial in the design of activatable PSs. In this direction, we report here, for the first time, a leucine aminopeptidase (LAP) activatable PDT agent (HCL), which is a red-shifted, water soluble and photostable brominated hemicyanine derivative. HCL was activated by endogenous LAP enzyme selectively in A549 (lung) and HCT116 (colon) cancer cells containing high LAP levels and induced effective photocytotoxicity with negligible dark toxicity. Furthermore, the fluorescence of the parent bromo-hemicyanine core was restored upon LAP-based activation in cancer cells. On the other side, no remarkable phototoxicity or fluorescence turn-on was detected in healthy L929 cells. Thus, HCL serves as an effective and tumour associated LAP-sensitive phototheranostic agent. We believe different cancer-associated analytes can be utilized in combination with near-IR absorbing scaffolds in the scope of activatable PDT designs to enrich the tumour-selective PS arsenal.
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    New class of red absorbing activatable PDT drugs
    (Amer Chemical Soc, 2019) Atakan, Gizem; Gunaydin, Gurcan; Gunbas, Gorkem; Department of Chemistry; Department of Chemistry; Almammadov, Toghrul; Kölemen, Safacan; Researcher; Faculty Member; Department of Chemistry; College of Sciences; College of Sciences; N/A; 272051
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    Organo-soluble dendritic zinc phthalocyanine: photoluminescence and fluorescence properties
    (Taylor & Francis Inc) Yabas, Ebru; Bicer, Emre; Baser, Pinar; Kul, Mehmet; Department of Chemistry; Department of Chemistry; Almammadov, Toghrul; Kölemen, Safacan; Researcher; Faculty Member; Department of Chemistry; College of Sciences; College of Sciences; N/A; 272051
    In this study, the spectroscopic measurements of the second generation dendritic zinc phthalocyanine (phthalocyanine dendrimer with tris) 2 were made and its potential to be used in optoelectronic applications was investigated. To examine the intramolecular energy transfer properties, fluorescence quantum yields were calculated and the contribution of first (phthalocyanine dendrimer with triethyl methanetricarboxylate) 1 and second 2 generation dendrimers to this energy transfer was investigated. The photoluminescence properties and optical band gap of the second generation zinc phthalocyanine 2 were investigated depending on the temperature. In addition, the quantum efficiency of singlet oxygen was calculated to evaluate the usability of this compound in photodynamic therapy. Also, aggregation behavior of compound 2 was examined in different solvents (DMF, DMSO and THF) and different concentrations in THF. To the best of our knowledge, this is the first study to examine the photoluminescence properties and temperature dependent changes of dendritic phthalocyanines.
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    Superior photodynamic therapy of colon cancer cells by selenophene-bodipy-loaded superparamagnetic iron oxide nanoparticles
    (2022) Karaman, Osman; Günbaş, Görkem; N/A; Department of History; Department of Chemistry; Department of Chemistry; N/A; Sertçelik, Kübra Nur Özvural; Almammadov, Toghrul; Kölemen, Safacan; Acar, Havva Funda Yağcı; Onbaşlı, Kübra; Master Student; Researcher; Faculty Member; Faculty Member; Researcher; Department of History; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Boron and Advanced Materials Application and Research Center (KUBAM) / Koç Üniversitesi Bor ve İleri Malzemeler Uygulama ve Araştırma Merkezi (KUBAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; N/A; College of Sciences; College of Sciences; N/A; N/A; N/A; 272051; 178902; N/A
    Development of targeted nanoparticles as carriers to deliver photosensitizers to cancer cells is highly beneficial for ensuring the expected therapeutic outcome of photodynamic therapy. Herein, polyacrylic acid (PAA) coated superparamagnetic iron oxide nanoparticles (SPIONs), conjugated with endothelial growth factor receptor (EGFR) targeting Cetuximab (Cet) were loaded with a BODIPY-based (BOD-Se-I) photosensitizer (Cet-PAA@SPION/BOD-Se-I) to achieve enhanced and selective photodynamic therapy on colon cancer cells. In vitro studies showed that Cet-PAA@SPION/BOD-Se-I improved phototoxicity dramatically compared to free BOD-Se-I on the HT29 cell line due to high uptake of the photosensitizer via endothelial growth factor receptor. Most importantly, the developed nano-agent completely eliminated the phototoxicity of BOD-Se-I on the healthy L929 cell line.
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    Mitochondria-targeting selenophene-modified BODIPY-based photosensitizers for the treatment of hypoxic cancer cells
    (Wiley-V C H Verlag Gmbh, 2019) Karaman, Osman; Gedik, M. Emre; Günaydin, Gürcan; Günbaş, Görkem; Department of Chemistry; Department of Chemistry; Almammadov, Toghrul; Kölemen, Safacan; Researcher; Faculty Member; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); College of Sciences; College of Sciences; N/A; 272051
    Two red-absorbing, water-soluble and mitochondria (MT)-targeting selenophene-substituted BODIPY-based photosensitizers (PSs) were realized (BOD-Se, BOD-Se-I), and their potential as photodynamic therapy (PDT) agents were evaluated. BOD-Se-I showed higher O-1(2) generation yield thanks to the enhanced heavy-atom effect, and this derivative was further tested in detail in cell culture studies under both normoxic and hypoxic conditions. BOD-Se-I not only effectively functioned under hypoxic conditions, but also showed highly selective photocytotoxicity towards cancer cells. The selectivity is believed to arise from differences in mitochondrial membrane potentials of healthy and cancerous cells. To the best of our knowledge, this marks the first example of a MT-targeted BODIPY PS that functions under hypoxic conditions. Remarkably, thanks to the design strategy, all these properties where realized by a compound that was synthesized in only five steps with 32% overall yield. Hence, this material holds great promise for the realization of next-generation PDT drugs for the treatment of hypoxic solid tumors.
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    Selective detection of carboxylesterase 2 activity in cancer cells using an activity-based chemiluminescent probe
    (Royal Soc Chemistry, 2022) Kailass, Karishma; Digby, Elyse M.; Beharry, Andrew A.; N/A; Department of Chemistry; Department of Chemistry; Özsan, Çağrı; Almammadov, Toghrul; Kölemen, Safacan; Master Student; Researcher; Faculty Member; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Boron and Advanced Materials Application and Research Center (KUBAM) / Koç Üniversitesi Bor ve İleri Malzemeler Uygulama ve Araştırma Merkezi (KUBAM); Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; N/A; N/A; 272051
    Carboxylesterase 2 (CES2) has crucial roles in both xenobiotic metabolism and formation of pathogenic states including cancer. Thus, it is highly critical to monitor intracellular CES2 activity in living cancer cells. Here, we report a CES2 activatable phenoxy 1,2-dioxetane based chemiluminescent agent (CL-CES2). The probe exhibited a selective turn-on response in the presence of CES2 enzyme and enabled detection of CES2 activity in three different cancer cells that possess varying enzyme concentrations with high signal to noise ratios. In contrast no signal was obtained with CES1, an isoform of CES2 enzyme. CL-CES2 marks the first ever example of a CES2-responsive chemiluminescent luminophore and holds a great potential in further understanding the roles of CES2 activity in tumorogenesis.
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    Resorufin enters the photodynamic therapy arena: a monoamine oxidase activatable agent for selective cytotoxicity
    (Amer Chemical Soc, 2020) Atakan, Gizem; Gunbas, Gorkem; Department of Chemistry; N/A; N/A; Department of Chemistry; Almammadov, Toghrul; Leylek, Özen; Özcan, Gülnihal; Kölemen, Safacan; Researcher; PhD Student; Faculty Member; Faculty Member; Department of Chemistry; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Boron and Advanced Materials Application and Research Center (KUBAM) / Koç Üniversitesi Bor ve İleri Malzemeler Uygulama ve Araştırma Merkezi (KUBAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); College of Sciences; Graduate School of Health Sciences; School of Medicine; College of Sciences; N/A; N/A; 185014; 272051
    A red-absorbing, water-soluble, and iodinated resorufin derivative (R1) that can be selectively activated with a monoamine oxidase (MAO) enzyme was synthesized, and its potential as a photodynamic therapy (PDT) agent was evaluated. R1 showed high O-1(2) generation yields in aqueous solutions upon addition of MAO isoforms, and it was further tested in cell culture studies. R1 induced photocytotoxicity after being triggered by endogenous MAO enzyme in cancer cells with a much higher efficiency in SH-SYSY neuroblastoma cells with high MAO-A expression. Additionally, R1 displayed differential cytotoxicity between cancer and normal cells, without any considerable dark toxicity. To the best of our knowledge, R1 marks the first example of a resorufin-based photosensitizer (PS) as well as the first anticancer drug that is activated by a MAO enzyme. Remarkably, the target PDT agent was obtained only in three steps as a result of versatile resorufin chemistry.