Heptametine cyanine-based hydrogel synthesis of which can do photodynamic therapy in the near-infrared region

Recently, photodynamic therapy (PDT) has emerged as one of the most widely used cancer treatment modalities. Although there are some clinically approved PDT agents, they have some certain drawbacks such as accumulation in healthy tissues, insolubility and aggregation in the physiological environment, difficulty in clearance from the body in a short time. Therefore, there is an urgent need for the development of new PDT agents. Cyanine dyes are organic dyes that can absorb and emit light in the phototherapeutic window (650-850 nm). Since the tissue light penetration depth is relatively high in the phototherapeutic window, materials pertinent to PDT have become very popular in this region of the electromagnetic spectrum. Hydrogels are three-dimensional polymeric materials that do not dissolve in water. They swell by absorbing water. They swell to an equilibrium volume in water. The amount of water they absorb is quite high. Also, hydrogels have highly permeable structures. Considering the above facts, the design and synthesis of a new organic dye that can be used as a PDT agent is investigated within the scope of the thesis. In addition, this dye was utilized in the synthesis of a new type of hydrogel. The experimental results validated that a near infrared cyanine-based hydrogel pertinent to PDT was successfully synthesized. At the final stage, the hydrogel was characterized by spectroscopic methods including SEM and TGA.