||Melanin is one of the most ubiquitous biological polymer widespread in our body tissue, and it has been shown that melanin has potential|
medical functions against free radicals, reactive oxygen species, tumor,
venin, virus, and heavy metal ions. However, its insolubility drastically
reduces its efficacy. We have shown previously that melanin can be
broken down to become nanometer-sized and water-dispersible by
pulsed-laser photo-fragmentation or by extended mechanical stir.
Through this, the exposed surface area could be increased by many orders of magnitude, dramatically increasing the efficiency of chemical and biological interactions. As a demonstration, we have explored the
efficacy of using the nanonized melanin in protecting cells from reactive
oxygen species.In this master thesis , we will explore the utilization of the nanonized melanin as a chelation agent against toxic metal ions.
In this paper, the possibility of using melanin nanoparticles as a new
kind of chelation agent has been studied. The chelating ability was
characterized by using Inductively Coupled Plasma Optical Emission
Spectrometer ( ICP-OES). The cell viability activity were characterized by using flow cytometer and ATP measurement. Result shows the melanin nanoparticles not only can chelate metal ions, more importantly,
but also can recovery cells from harm of Pb2+ ion. First, the chelation
ability of melanin on Pb2+ was studied. Then nanolized melanin was been utilized to in-vitro experiment. it was found the melanin nanoparticles can cure cells from harm of metal ion, but DMSA can not. We hypothesize that the nanolized melanin could diffuse into the cells to spit out lead-ion which had been swallowed by cells, and increase cells ATP. This result indicates that the nanolized melanin did have the possibility of being a new chelating agent.
|| Tchounwou PB Yedjou CG Petlolla AK Sutton DJ. Heavy metals|
toxicity and the environment. NIH Public Access, 101:113–164, 2014.
 Lowry JA. Oral chelation therapy for patients with lead poisoning.
Am Acad Pediatr, 116: 1036-1046, 2010.
 Pombeiro-Sponchiado SR Goncalves RDR. Antioxidant activity of
the melanin pigment extracted from aspergillus nidulans. Biol Pharm
Bull, 28(6):1129–1131, 2005.
 Niwano Y Tada M, Kohno M. Scavenging or quenching effect
of melanin on superoxide anion and singlet oxygen. J. Clin.
Biochem. Nutr., 46(3):224–228, 2010.
 Sichel G Brai M Palminteri MC, Sciuto S. Seasonal dependence
of ESR feature of frog melanins. Comp. Comparative Biochemistry
and Physiology Part B: Comparative Biochemistry, 70(3):611-613,
 Geremia E et al. Vanella A, Sichel, G. Eumelanins as free
radicals trap and superoxide dismutase activities in Amphibia.
Comparative Biochemistry and Physiology Part B: Comparative
Biochemistry, 79(1): 67-69, 1984.
 Sarna T Pilas B Land EJ, Truscott TG. Interaction of radicals
from water radiolysis with melanin. Biochimica et Biophysica Acta
(BBA)-General Subjects, 883(1): 162-167, 1986.
 Scalia M Geremia E Corsaro C Santoro C Baratta D, Sichel G.
Lipid peroxidation in pigmented and unpigmented liver tissues:
protective role of melanin. Pigment Cell Research, 3(2): 115-119,
 Burkhart CN Burkhart CG. The mole theory: primary function
of melanocytes and melanin may be antimicrobial defense
and immunomodulation (not solar protection). Int. J. Dermatol.,
 Mackintosh JA. The antimicrobial properties of melanocytes,
melanosomes and melanin and the evolution of black skin. J.
Theor. Biol., 211(2):101–113, 2001.
 Garger SJ Dousman L Grill LK Tus’ e D Mohagheghpour N,
Waleh N. Synthetic melanin suppresses production of proinflammatory
cytokines. Cell. Immunol., 199(1):25–36, 2000.
 Michel M et al. Ball V, Frari DD. Deposition mechanism and
properties of thin polydopamine films for high added value applications
in surface science at the nanoscale. BioNanoSci., 2(1):16–
 Irimia-Vladu M Mostert AB Schwenn PE Meredith P, Bettinger
CJ. Electronic and optoelectronic materials and devices
inspired by nature. Rep. Prog. Phys., (034501):1–36, 2013.
 Sivakumar K Kim S-K Manivasagan P, Venkatesan J.
Actinobacterial melanins: current status and perspective for the
future. World J. Microbiol. Biotechnol., 29:1737–1750, 2013.
 Gasyna EM Kobori Y Rezaei KA-Norris JR Jr. Seagle BL,
Rezai KA. Time-resolved detection of melanin free radicals quenching
reactive oxygen species. Journal of the American Chemical
Society, 127(32):11220–11221, 2005.
 Potts AM Au PC. The affinity of melanin for inorganic ions. Exp.
Eye, 22(5): 487–491, 1976.
 Lee J-K Kim DJ, Ju K-Y. The synthetic melanin nanoparticles
having an excellent binding capacity of heavy metal ions. Bull. Korean
Chem. Soc., 33(11): 3788–3792, 2012.
 Chu P et al. Schweitzer AD, Revskaya E. Melanin-covered
nanoparticles for protection of bone marrow during radiation therapy
of cancer. Int. J. Radiat. Oncol. Biol. Phys., 78(5): 1494–1502, 2010.
 Mikirova N Casciari J, Hunninghake R. Efficacy of oral DMSA
and intravenous EDTA in chelation of toxic metals and improvement
of the number of stem/progenitor cells in circulation. Translational
Biomedicine, 2(2), 2011.