
Modelling coupled dynamics of diffusive-convective mass transfer in microfluidic systems and determining hydrodynamic dispersion coefficient. Journal of Taiwan Institute of Chemical Engineers, 80, 100-106.
Ece Yildiz-Ozturk, Mesut Yucel, Cahit Muderrisoglu, Sayit Sargin, Ozlem Yesil-Celiktas (2017)
One of the challenges in mathematical modelling of microchips is the lack of available data for dispersion coefficients of biomolecules. The main focus of this study was to determine the hydrodnamic dispersion coefficients of the model substrates, 4-Nitrophenyl-β-d-glucopyranoside (pNPG_1) and 4-Nitrophenyl-β-d-glucuronide (pNPG_2) for β-glucosidase and β-glucoronidase...
Supercritical CO2 extraction of hydrocarbons from Botryococcus braunii as a promising bioresource. Journal of Supercritical Fluids, 130, 261-266.
Ece Yildiz-Ozturk, Ozlem Yesil-Celiktas (2017)
Microalgae has been a sustainable resource for producing bio-based products and hydrocarbon rich varieties are significant sources for converting into green naphtha and further to ethylene and propylene. The objective of this study was to develop an optimized supercritical CO2 method for extracting hydrocarbons from Botryococcus braunii...
Optimizing subcritical water extraction of Morus nigra L. fruits for maximization of tyrosinase inhibitory activity. Journal of Supercritical Fluids, 127, 15-22.
Halil Koyu, Aslihan Kazan, Taylan Kurtulus Ozturk, Ozlem Yesil-Celiktas, Zeki Haznedaroglu (2017)
The process of preparing extracts for pharmaceutical industry from natural resources is a challenge to obtain effective constituents besides using resources efficiently considering public health and environment. Advanced extraction technologies aim to provide high efficiency and selectivity apart from decreasing the demand for organic solvents causing toxic residuals. In line with this objective, optimization of subcritical water extraction of Morus nigra L. fruits had been carried out with response surface methodology...
Formulation of organic and inorganic hydrogel matrices for immobilization of β-glucosidase in microfluidic platform. Engineering in Life Sciences, 17, 714-722.
Aslihan Kazan, Marcel Heymuth, Dilan Karabulut, Seref Akay, Ece Yildiz-Ozturk, Rabia Onbas, Cahit Muderrisoglu, Sayit Sargin, Rene Heils, Irina Smirnova, Ozlem Yesil-Celiktas (2017)
The aim of this study was to formulate silica and alginate hydrogels for immobilization of β‐glucosidase. For this purpose, enzyme kinetics in hydrogels were determined, activity of immobilized enzymes was compared with that of free enzyme, and structures of silica and alginate hydrogels were characterized in terms of surface area and pore size. The addition of polyethylene oxide improved the mechanical strength of the silica gels and 68% of the initial activity of the enzyme was preserved after immobilizing into tetraethyl orthosilicate–polyethylene oxide matrix where the relative activity in alginate beads was 87%...
An injectable alginate-based hydrogel for microfluidic applications. Carbohydrate Polymers, 161, 228-234.
Seref Akay, Rene Heils, Hoc Khiem Trieu, Irina Smirnova, Ozlem Yesil-Celiktas (2017)
The objective of this study was to develop an injectable alginate based formulation for immobilizing enzymes into microfluidic systems. The gelation was induced upon lowering the pH by addition of d-glucono-δ-lactone (GDL) and release of Ca+ ions from solid CaCO3. The effects of GDL concentration on enzymatic activity and gelation time were investigated...
Cytotoxic responses of carnosic acid and doxorubicin on breast cancer cells doped in butterfly-shaped microchips in comparison to 2D and 3D culture systems. Cytotechnology, 69(2), 337-347.
Ece Yildiz-Ozturk, Sultan Gulce-Iz, Muge Anil, Ozlem Yesil-Celiktas (2017)
Two dimensional (2D) cell culture systems lack the ability to mimic in vivo conditions resulting in limitations for preclinical cell-based drug and toxicity screening assays and modelling tumor biology. Alternatively, 3D cell culture systems mimic the specificity of native tissue with better physiological integrity. In this regard, microfluidic chips have gained wide applicability for in vitro 3D cancer cell studies...
Synthesis of silica-PAMAM dendrimer nanoparticles as promising carriers in Neuro blastoma cells. Analytical Biochemistry, 519, 1-7.
Ozlem Yesil-Celiktas, Cansu Pala, E. Oyku Cetin-Uyanikgil, Canan Sevimli-Gur (2017)
Mesoporous silica carriers are emerging as therapeutic drug delivery systems. The objective of this study was to develop a formulation for synthesizing silica-PAMAM dendrimer hybrid nanoparticles with sol-gel technique. Subsequently, black carrot anthocyanins were encapsulated and investigated for their capability in terms of inhibiting the proliferative effects of neuroblastoma (Neuro 2A)...
Green extraction processes focusing on maximization of black carrot anthocyanins along with cytotoxic activities. Food Analytical Methods, 10 (2), 529-538.
Cansu Pala, Canan Sevimli-Gur, Ozlem Yesil-Celiktas (2017)
Interest in anthocyanins has intensified due to their health promoting ability by reducing the risk of atherosclerosis, cancer, diabetes, and neurodegenerative disorders. In this study, anthocyanin extraction from black carrot was optimized by using solvent, ultrasound-, and microwave-assisted techniques, where the independent variables were temperature, liquid/solid ratio, and extraction time...
In vitro tumor suppression properties of blueberry extracts in liquid and encapsulated forms. European Food Research and Technology, 243, 1057-1063.
Aslihan Kazan, Canan Sevimli-Gur, Ozlem Yesil-Celiktas, Nurhan Turgut Dunford (2017)
Blueberries are rich in anthocyanins. Short shelf life of fresh blueberries and chemical instability of anthocyanins make the handling of blueberries very challenging. Hence, the objectives of this study are to characterize anthocyanin contents of blueberry water and acetone extracts and to encapsulate the extracts with chitosan. The encapsulated material was analyzed for its particle size distribution, thermal characteristics, and efficacy to reduce cancer cell proliferation...