@phdthesis{Grebinyk2021, author = {Grebinyk, Anna}, title = {Synergistic Chemo- and Photodynamic Treatment of Cancer Cells with C\(_{60}\) Fullerene Nanocomplexes}, doi = {10.25972/OPUS-22207}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222075}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Recent progress in nanotechnology has attracted interest to a biomedical application of the carbon nanoparticle C60 fullerene (C60) due to its unique structure and versatile biological activity. In the current study the dual functionality of C60 as a photosensitizer and a drug nanocarrier was exploited to improve the efficiency of chemotherapeutic drugs towards human leukemic cells. Pristine C60 demonstrated time-dependent accumulation with predominant mitochondrial localization in leukemic cells. C60's effects on leukemic cells irradiated with high power single chip LEDs of different wavelengths were assessed to find out the most effective photoexcitation conditions. A C60-based noncovalent nanosized system as a carrier for an optimized drug delivery to the cells was evaluated in accordance to its physicochemical properties and toxic effects. Finally, nanomolar amounts of C60-drug nanocomplexes in 1:1 and 2:1 molar ratios were explored to improve the efficiency of cell treatment, complementing it with photodynamic approach. A proposed treatment strategy was developed for C60 nanocomplexes with the common chemotherapeutic drug Doxorubicin, whose intracellular accumulation and localization, cytotoxicity and mechanism of action were investigated. The developed strategy was revealed to be transferable to an alternative potent anticancer drug - the herbal alkaloid Berberine. Hereafter, a strong synergy of treatments arising from the combination of C60-mediated drug delivery and C60 photoexcitation was revealed. Presented data indicate that a combination of chemo- and photodynamic treatments with C60-drug nanoformulations could provide a promising synergetic approach for cancer treatment.}, subject = {cancer}, language = {en} } @article{WaeldchenLehmannKleinetal.2015, author = {W{\"a}ldchen, Sina and Lehmann, Julian and Klein, Teresa and van de Linde, Sebastian and Sauer, Markus}, title = {Light-induced cell damage in live-cell super-resolution microscopy}, series = {Scientific Reports}, volume = {5}, journal = {Scientific Reports}, number = {15348}, doi = {10.1038/srep15348}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145207}, year = {2015}, abstract = {Super-resolution microscopy can unravel previously hidden details of cellular structures but requires high irradiation intensities to use the limited photon budget efficiently. Such high photon densities are likely to induce cellular damage in live-cell experiments. We applied single-molecule localization microscopy conditions and tested the influence of irradiation intensity, illumination-mode, wavelength, light-dose, temperature and fluorescence labeling on the survival probability of different cell lines 20-24 hours after irradiation. In addition, we measured the microtubule growth speed after irradiation. The photo-sensitivity is dramatically increased at lower irradiation wavelength. We observed fixation, plasma membrane permeabilization and cytoskeleton destruction upon irradiation with shorter wavelengths. While cells stand light intensities of similar to 1 kW cm\(^{-2}\) at 640 nm for several minutes, the maximum dose at 405 nm is only similar to 50 J cm\(^{-2}\), emphasizing red fluorophores for live-cell localization microscopy. We also present strategies to minimize phototoxic factors and maximize the cells ability to cope with higher irradiation intensities.}, language = {en} }