title: Evaluation of lithium naphthalocyanine (LiNc) microcrystals for biological EPR oximetry.
abstract: A new paramagnetic crystalline material, namely, lithium naphthalocyanine (LiNc), whose electron-paramagnetic-resonance (EPR) line width is highly sensitive to oxygen content, has been evaluated for use as oximetry probe in cells and tissues. Previously,we reported on the synthesis, structural framework,magnetic and oxygen-sensing properties of LiNc microcrystalline powder (Pandian et al, J. Mater. Chem. 19, 4138, 2009). The material exhibited a single, sharp EPR line that showed a highly linear response of its width to surrounding molecular oxygen (pO(2)) with a sensitivity of 31.2 mG/mmHg. In the present study, we evaluated the suitability of this material for in vivo oximetry in biological systems. We observed that the probe was stable in tissues for more than two months without any adverse effect on its oxygen-sensing properties. We further demonstrated that the probe can be prepared in sub-micron sizes for uptake by stem cells. Thus, the high oxygen sensitivity, biocompatibility, and long-term stability in tissues may be useful for high-resolution EPR oximetry.
authors: Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA.
authors: Ramasamy P
authors: RP
authors: Pandian
authors: Simi M
authors: SM
authors: Chacko
authors: M Lakshmi
authors: ML
authors: Kuppusamy
authors: Brian K
authors: BK
authors: Rivera
authors: Periannan
authors: P
authors: Kuppusamy
mesh_terms: D000818:Animals; D003460:Crystallization; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D051379:Mice; D008809:Mice, Inbred C3H; D010092:Oximetry / Q000295:instrumentation*; D010100:Oxygen / Q000378:metabolism*; D011166:Porphyrins / Q000737:chemistry*; D051381:Rats; D011916:Rats, Inbred F344; D013113:Spin Labels
chemical_list: D011166:Porphyrins; D013113:Spin Labels; C487013:lithium octa-n-butoxynaphthalocyanine; D010100:Oxygen