NO Photorelease And Its Photobiology Applications

As a signal transfer molecule, nitric oxide (NO) plays an important role in various physiological processes, including the control of cardiovascular system, nervous system, immune response and apoptosis. In recent years, with the rapid development of the photobiology and photodynamic therapy, the photoactive NO donors have been paid more and more attention by researchers. How to delieve NO to the specific physiological target and to control NO release at fixed times and with fixed quantity are of great significance. Photophysics and photochemistry method has many advantages, for example, you can easily control the time, dose and release at specific location, so as to achieve the purpose of effective regulation of physiological processes.Due to the special photoreactivity and stability, ruthenium-nitric oxide complexes receive special attention by researchers. The discovery and use of the specific light-sensitive{Ru-NO} complexes is important for the design of NO donors, the regulation of physiological processes and the development of new methods for treating the disease.In this paper, we used a variety of accurate methods in order to measure NO radicals released by cis and trans-[Ru(OAc)-(2mqn)2NO] complexes upon photoirradiation. We compared and studied the binding and the interactions of the two complexes with bio-macromolecule DNA; explored the inhibition acvitity against different tumor cell lines upon photoirradiation; obtained the basic method of quantitatively controlling the quantity of NO radicals released by adjusting the photoirradiation; established experimental methods to improve their inhibition acvitity against the growth of tumor cells by photoirradiation.The main works of this paper are as follows:First, the physiological roles and related research progress of NO were introduced and summarized, and its dissociation reaction induced by photo- irradiation is analyzedSecond, electron paramagnetic resonance (EPR) technology and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) were used to confirm the release of NO radicals from cis and trans-[Ru(OAc)(2mqn)2NO] complexes which were irradiated. NO radicals released under different photoirradiation conditions were measured by NO selective sensor.Third, the binding of cis and trans-[Ru(OAc)(2mqn)2NO] with CT-DNA was studied by fluorescence spectroscopy, and quenching constant was calculated. Also, the mechanism for photocleavage of pBR322DNA when cis and trans-[Ru(OAc)(2mqn)2NO] was added, was investigated.Fourth, the in vitro cytotoxic activities of cis and trans-[Ru(OAc)-(2mqn)2NO] complexes were evaluated against Hela, HepG2, and C6 glioma tumor cell lines upon and without photoirradiation via MTT method.