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Title: Mechanical and photo-fragmentation processes for nanonization of melanin to improve its efficacy in protecting cells from reactive oxygen species stress

It has been well established ex vivo that melanin has the ability of scavenging free radicals and reactive oxygen species (ROS), besides other functions. Therefore, we propose to utilize nanonized melanin as medication against acute oxidative stress. For this purpose, we developed and characterized two techniques based on mechanical stir and photo-fragmentation using femtosecond laser pulses, respectively, for disintegration of suspended melanin powder to produce nanometer-sized and water-dispersible melanin. This resolves a major obstacle in the medical and industrial applications of melanin. The viabilities of cultured retinal pigment epithelium (RPE) cells exposed to exogenous H{sub 2}O{sub 2} stress and treated with various conditions of melanin and irradiation were compared. It was found that melanin could be nanonized very effectively with the techniques, and nanonized melanin exhibited a much stronger effect than unprocessed melanin on raising the viability of cultured RPE cells under acute ROS stress. The effect was even more prominent without simultaneous light irradiation, promising for effective in vivo application to the whole body.
Authors:
 [1] ;  [2] ;  [3] ; ;  [4] ;  [1] ;  [5] ;  [2] ;  [2]
  1. Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)
  2. (China)
  3. Graduate Institute of Biophysics, National Central University, Jhongli 32001, Taiwan (China)
  4. Department of Physics, National Central University, Jhongli 32001, Taiwan (China)
  5. Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)
Publication Date:
OSTI Identifier:
22413110
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COMPARATIVE EVALUATIONS; EPITHELIUM; HYDROGEN PEROXIDE; IRRADIATION; LASER RADIATION; MELANIN; OXIDATION; OXYGEN; POWDERS; RHODOPSIN; STRESSES; VISIBLE RADIATION; WATER