Research
The projects listed below are conducted by our team.
Carbon Quantum Dot Synthesis With Hot Bubble Synthesis (HBBBS) Method and Its Characterization (Acibadem University General Research Projects Support Program)
Project Leaders: Beste Dipçin, Bora Güvendiren
Consultant: Assoc. Prof. Bükem Tanören, Assoc. Prof. Kadriye Kızılbey, Dr. Selçuk Birdoğan
This project is about synthesizing carbon quantum dots (C-dots) from 98% sulfuric acid, pure acetone, and sodium hydroxide with a newly developed method, hot bubble synthesis (HBBBS) method, and understanding the chemical and physical properties of C-dots alongside characterizing them by UV-Vis Spectrophotometry, Fourier Transform Infrared Spectroscopy (FT-IR), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Dynamic Light Scattering (DLS), Zeta Potential analysis, and fluorescence microscopy.
Formation of TTR Gene Targeted Nanoparticles Investigating the Effect of Them on Transthyretin Protein Production and Cell Viability Alongside Observation of Their Cell Localization Utilizing Confocal Microscope (TUSEB-A)
Project Leader: Beste Dipçin
Consultant: Assoc. Prof. Bükem Tanören, Assist. Prof. Özgül Gök Özatay
Genetic transthyretin amyloidosis (hATTR) is a genetic rare disease that occurs because of mutation(s) in the TTR gene that has become endemic in a few countries and causes the protein structure of transthyretin to deteriorate. This disease causes a complex, multifunctional system disorder that affects many systems, especially the nervous and cardiovascular systems. In the treatment of the disease, liver transplantation, transthyretin protein stabilizing drugs, and gene-targeted drugs are used. Gene silencing using the RNA interference (RNAi) mechanism is one of the most preferred methods in gene-targeted drug delivery systems. Gene therapies based on gene silencing by RNA interference hold great potential for the treatment of hATTR. Within the scope of this project, conjugation of PEG, HIV-1 Tat peptide, and carbon quantum dot to chitosan polymer, physical encapsulation of the obtained coating to the TTR gene-targeted siRNA molecules into the formed chitosan complex, characterization and optimization of the nanoparticle, measurement of cytotoxicity of the resulting nanoparticle in cell lines are aimed. It is planned to observe the cell localization utilizing a confocal microscope and to investigate the changing transthyretin (TTR) protein levels in the cells with Protein Immunoblot (Western Blot). In addition, stabilization and drug release analyzes of the nanoparticle will be performed. Obtained nanoparticles’ analysis and characterization will be done with Fourier Transform Infrared Spectrophotometer (FT-IR), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Zeta analysis, Nanodrop, agarose gel electrophoresis Dynamic Light Scattering Spectrometer (DLS) and Liquid Chromatography - Mass Spectrometry - Mass Spectrometry (LC-MSMS) instrument. With the findings obtained in the project, it is aimed to produce a gene therapy that can be used in the treatment of hATTR.
Radiation and Photobleaching Characterization of Theranostic Quantum Dots (TUBITAK 2209-A)
Project Leader: Bora Güvendiren
Consultant: Assoc. Prof. Bükem Tanören
Within the scope of this project, it is aimed to measure the resistance of the theranostic quantum dots against photobleaching together with the absorption and radiation characterization. In line with the information obtained, it is aimed to discuss the potential of an alternative agent that can be used for treatment while imaging more effectively and with less cost for the imaging and diagnostic methods used today.
Theranostic quantum dots are nanocrystals made of luminous and semiconductor materials. Photobleaching is a condition in which the fluorescence intensity decreases after long-term use of a fluorescent molecule, which occurs as a result of modification of covalent bonds or reaction of the fluorophore with surrounding molecules. However, stable theranostic quantum dots have higher resistance to photobleaching.
Theranostic quantum dots are superior contrast agents with the advantage that they have light efficiencies, more stable particles, more light scattering, lower cytotoxicity than most contrast agents used today, more resistant to photobleaching, and simultaneous treatment with imaging.
In this project, graphene quantum dots of 2 and 10-nanometer sizes will be used as theranostic quantum particles. Characterization will be made by examining the absorption spectra with a UV-VIS spectrophotometer and the luminescence spectra with an inverted fluorescence microscope. After this process, the resistance of the theranostic quantum dots to photobleaching will be evaluated by following the radiation spectra with fluorescence microscopy.
With the information to be obtained at the end of this project, an alternative to the contrast agents used in the imaging methods mentioned before will be created. In addition, it will be possible to discuss the potential of theranostic quantum dots for drug delivery methods, imaging, and simultaneous treatment of many non-tumor diseases, together with the properties to be examined.
Imaging of Fibrocalcific Carotid Plaques by Using Confocal Microscope (TUBITAK 2209-A)
Project Leader: Eda Nur Yetim
Consultant: Assoc. Prof. Bükem Tanören
In humans, the development of structures called plaques in the inner part of the main carotid arteries, which are located one on each side of the neck, is called carotid artery disease, and the formation of plaques in the inner part of the arteries is called atherosclerosis. Since plaque formation will cause narrowing in the inner diameter of the vessels over time, carotid artery disease may lead to dangerous consequences such as cerebrovascular attack and ischemic stroke for human health in the future. At the same time, carotid artery atherosclerosis is one of the leading causes of ischemic stroke. Therefore, it is important to determine the vulnerability of these plaques in order to reduce the risk of ischemic stroke. The plaques, especially if fragile, could rupture and cause paralysis, because the greater the vulnerability of the plaques, the greater the risk of rupture and stroke. Within the scope of this project, it is aimed to visualize the fibrocalcific plaques formed in the carotid artery vessels in humans with a confocal microscope in detail and to determine the dependence of the calcification rate according to age and gender. Since the confocal microscope is a laser scanning microscope and scans samples point by point, it offers high resolution. Observation of plaques in high resolution is important for accurate diagnosis of vulnerability. Considering the literature studies, since there is not yet a system that can detect the fragility sensitivity of these plaques in the clinic, it will be possible to visualize these structures in detail and to diagnose dangerous fragile plaques at a micron level with a confocal microscope. Hence, visualization of plaques and the observation of micro-calcifications or stained calcifications in them, which are indicative of plaque sensitivity, also play an important role in determining that larger calcifications are stable and no longer threatening. In addition, after this imaging process is completed, correlation determination of calcification rate according to age and gender will be possible.
Preparation of Peptide Conjugated Quantum Dots for Imaging Applications and Characterization with Fluorescent Microscopy (TUBITAK 2209-A)
Project Leader: Şevval Yıldız
Consultant: Assoc. Prof. Bükem Tanören
Within the scope of this project, it is aimed to prepare peptide conjugations of 3 types of quantum dots, graphene, cadmium tellurium/cadmium sulfide (CdTe/CdS) and silver indium sulfide (AgInS2), which are suitable imaging agents for medical imaging, and to evaluate the luminescence ability of the formed nanoparticle with fluorescence microscopy. Quantum dots are nanocrystalline semiconductor inorganic nanoparticles that have strong and long-lasting luminescence and exhibit unique optical, spectropic and physicochemical properties for biomedical application. In this project, 3 types of quantum dots will be conjugated with arginine-rich peptides at different concentrations and in different peptide-quantum dot ratios to identify suitable data for future bioimaging and targeting applications. Since the electrostatic interaction of peptides and quantum nanoparticles will be utilized within the scope of the project, arginine-rich peptides that contain amino acids that carry electrical charge and that enter cells will be used. Peptides will be synthesized by solid phase peptide synthesizer. The synthesized peptides will be purified by HPLC and then confirmed by mass determination by LC-MS. Quantum dots-peptides bioconjugates will be prepared by non-covalent interactions. This is because non-covalent interactions tend to produce simpler, more efficient, and smaller nanoparticles. This type of attachment will also enable to overcome obstacles such as cytotoxicity and rejection into the cell that may be experienced in cellular internalization. Electrophoresis gel retardation test will be used to examine the binding rates and bond interaction of peptides with quantum dots. This process will be viewed with an inverted fluorescent microscope, and besides evaluating the binding abilities of the peptides with the quantum dots, the interaction between them will also be observed.
Imaging Effects of the PEGylation on Quantum Dot
Physically Absorbed Pep-1 Complexes Given Cells' Viability and Given Complexes' Localization Utilizing Confocal Microscopy
Project Leader: Beste Dipçin
Consultant: Assoc. Prof. Bükem Tanören, Assist. Prof. Özgül Gök Özatay, Dr. Selçuk Birdoğan
The goal of this project is to synthesize biocompatible bioimaging agents (quantum dots) and make them more biocompatible to decrease the amount of cell degradation when they are used in biological systems. This is achieved through PEGylation of quantum dots. After PEGylation, PEGylated and non-PEGylated quantum dots are physically absorbed by an amphipathic cell-penetrating peptide that can go through the cell membrane via translocation, Pep-1. Confocal microscopy is utilized for the characterization of samples.
Neuromodulation by Targeting Magneto-electric Nanoparticles
Project Leaders: Şevval Yıldız
Consultants: Assoc. Prof. Bükem Tanören, Assist. Prof. Melis Yavuz
In this project, it is aimed to use magneto-electric nanoparticles to artificially stimulate the neural activity in the Central Nervous System. This presents a novel method for coupling electric signals in the neural network to magnetic dipoles in nanoparticles, allowing a non-invasive approach. This project will be composed of the synthesis of Magneto-electric nanoparticles (MEN), the synthesis of functionalized Hyaluronic Acid, the fabrication of 3D hydrogels as a biomimetic matrix, physical and chemical characterization of hydrogels, cell culture/encapsulation/viability/morphology stages, computational simulation, animal modeling, histological and immunofluorescence imaging of spinal cord and brain.