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TOMSK, Aug 1 – RIA Tomsk. Scientists of Tomsk Polytechnic University (TPU)
found a way to improve antioxidant properties of beta-carotene (pro-vitamin A)
due to use of polymeric nanospheres which transport this substance in a human
body, prolonging biological activity of substance, the press service of the
university reports on Wednesday.
It is specified that beta-carotene is
the most known form of pro-vitamin A. It is powerful antioxidant and an
immunostimulator, which prevents new growths. However, it is unstable and is
badly dissolved in water that limits its application in pharmacology. TPU
scientists offered to use polymeric nanospheres as transport for molecules of
beta-carotene.
"The idea consisted in development
of special carriers on the basis of natural polymers that molecules of
beta-carotene were delivered to the right place and were released not at a
time, and gradually. In addition, it was necessary to increase water solubility
of beta-carotene for its best sorption in an organism. We suggested to place
beta-carotene molecules in spheres – polyplexes – from chitosan and nucleic
acids", – the employee of Research School of Chemistry & Applied
Biomedical Sciences Antonio Di Martino is quoted.
It is noted that the size of polyplexes
is 100 nanometers, and each such sphere may contain up to 400 micrograms of
beta-carotene. Process of their receiving doesn't demand global installations
and the subsequent cleaning of the final product of toxic substances that is
important in the conditions of large production.
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"Release of beta-carotene happens
due to natural and gradual destruction of polyplexes under the influence of
acidity, PH, temperature, additional amino acids and enzymes. Depending on
these conditions for release up to 90% of the beta-carotene introduced in
polyplexes as several hours, and one week can be required", – Di Martino
is quoted.
It is added that the made experiments
have shown that the antioxidant activity of beta-carotene increased because of
polyplexes. In case with beta-carotene 50% of free radicals were destroyed in a
free form in 20 minutes in solution, and in a case from polyplexes – more than
90%. Also tests have shown that polyplexes don't influence viability of cages
even after 72-hour contact that confirms their low toxicity.