Browsing by Subject "Phototherapy."

Now showing 1 - 5 of 5

Open Access
Chiral Bodipy dyes & photosensitizers for photodynamic therapy and dye-sensitized solar cells
(2013) Çakmak, Yusuf
Bodipy is a molecule with many superior properties. After its discovery in 1968, most of the features were not recognized until mid 1990s. Thereafter, many research papers and patents have been produced and the number of publications and citations is still on the rise today. An important fraction of the research done with this fluorophore is in chemosensing field to probe various analytes including anions, cations and even biomolecules. However, in this research we have focused on different areas of subjects and tried to find novel applications for these dyes. First, we designed orthogonal bodipy dimers for efficient triplet photosensitization without heavy atoms in contrast to most other sensitizers and efficient singlet oxygen generation was achieved (Φ∆=0.51). In the second project, calix[4]arene molecules were designed and synthesized as carriers for photodynamic therapy, potentially behaving as a molecular basket carrying the agents to the tumor tissues. Later, we focused on obtaining axial chiral molecules by using solely bodipy dyes, and we were able to obtain enantiopure fragments were separated by using chiral HPLC. These rare molecules are desirable for modern biological labeling and advanced optoelectronic devices. Finally, we designed bodipy dyes for dye sensitized solar cells by adapting relevant functional groups, and following synthesis work, we constructed cells to assess the design parameters via measuring the electrical output results.
Open Access
Design, synthesis and characterization of activatable photosensitizers for photodynamic therapy
(2012) Çakmak, Fatma Pir
Search for new noninvasive methods for diseases has been significant question for years. Therapeutic properties of light are combined with proper chromophore in order to create fundamentals of photodynamic therapy which is a new treatment modality for cancer and other various non-oncological diseases. The method relies on the activation of photosensitizer by using light of certain wavelength and generation of cytotoxic singlet oxygen species in response. Reactive oxygen species kill the targeted tissue within smaller effective diameter through apoptosis/ necrosis mechanism. Through this method, new PDT agents can be proposed and their properties can be tuned by manipulation of other photophysical processes. In this thesis, synthesis, characterization novel water soluble, near IR absorbing Bodipy photosensitizer will be discussed. As opposed to other photosensitizers in literature, this photosensitizer is rationally designed to have singlet oxygen generation capability only in cancer tissue as a result of glutathione triggered activation.
Open Access
Molecular logic gates in the activity modulation of potential PDT agents & rational design of selective chloride sensors
(2013) Erbaş-Çakmak, Sündüs
Considering the time arrow of science, things are getting smaller and smarter as the information grows immensely. More is known about the molecular and genetic basis of diseases, and therapies become more personalized accordingly. In parallel, organic devices are becoming progressively intelligent. Molecular logic gates increase the flexibility in functionality of the Boolean logic operations, and allow the creation of demanding complex functionalities for different purposes. The missing link between the design of any kind of complex logic operation and assignment of a real function is addressed by our work. A dual-activatable photosensitizer acting as an AND logic gate enables a more selective photodynamic therapy with the use of biologically relavant concentrations of acid and glutathione. Additionally, with a combinatorial therapy and imaging approach, a proof of principle theranostic device with DEMUX logic behaviour is developed to select between singlet oxygen generation and emission in response to an address input (acid) in organic solvent. In another project, relay of information between two independent logic gates embedded into a physically constraining microenvironment was successfully demonstrated to report the activity of a pH-activatable photosensitizer as an enhanced emission. Independently, a series of highly selective fluorescent chloride anion sensors based on BODIPY-triazolophane conjugate are introduced with a surprisingly large dynamic response range.
Open Access
Photosensitizers for photodynamic action and synthesis of modules for a molecular demultiplexer
(2014) Durgut, Tuğçe
Photodynamic therapy (PDT) is a new therapeutic methodology that uses light as a distinguishing tool for the treatment of diseased cells. In recent years PDT has become one of the most preferred therapies because it is innocent for the healthy cells and tissues while diagnosing and curing the malignant cells and tissues. Bodipy is one of the most favorite fluorophore in this field due to its excellent chemical and physical properties. Logic gates are widely used in modern technology as the fundamentals of logical operations for the development of science. The progressive advances leads to the emergence and growth of molecular logic gates. Molecular logic gates can be used for the diagnosis and therapies of disease which are originated from the heredity. In addition, they occupy an important place in the theoretical and practical use of photodynamic therapy. In the first part of my thesis, we designed and synthesized a calix[4]arene-Bodipy conjugate molecule as a carrier for the photodynamic therapy agents. It is an amphiphilic delivery molecule that is utilized for the curing of tumor tissues. In the second part, we synthesized modules for molecular logic gate function, DEMUX (demultiplexer), serving as a theranostic device which selects either singlet oxygen channel or energy transfer between the modules depending on the inputs. The superiority of the project is that it serves a realistic pathway for the PDT.
Open Access
Tetrastyryl-BODIPY dyes as potential photosensitizers for photodynamic theraphy
(2011) Yeşilgül, Nisa
Photodynamic therapy (PDT) is a novel methodology for a wide range of treatments of cancerous and noncancerous diseases. Success of treatment and photodynamic action is highly dependent the performance of PDT agents. Therefore, PDT agents with unique photophysical properties are required in clinical applications. There are several photosensitizers in literature and some are available. However, most of them less than ideal due to limitations such as low molar absorptivity and photo stabilities. In this study, we synthesized near-IR tetrastyryl-Bodipy derivatives as photosensitizers. These sensitizers have strong absorption in therapeutic region and are good photo-generator of singlet oxygen. They are promising for photodynamic therapy with their favorable properties.