DELIVERY SYSTEMS
CH2 COO· Na+ O
Glucuronic acid
O OH OH Hyaluronic acid Figure 3: Chitin and hyaluronic acid have the same backbone.
However, in the majority of cases, the active release follows more than one type of mechanism, firstly depending on the medium molecular weight of CN and HA, the global method of preparation, and particle size of the obtained nanoparticles. In conclusion, these CN-nanoparticles have shown great utility in controlled release and targeting studies of almost all classes of bioactive molecules of cosmetic use because of their interesting and different physicochemical activity and interesting skin efficacy connected with the electrical charges they possess. Moreover, the numerous acethyl groups characterising CN crystallites should be responsible for the supposed global effect on the wellness verified by the use of cosmetic products formulated by the NICE-approach (Nervous, Immune, Cutaneous and Endocrine systems) reported in some of our studies.20–22 As recently reported23–26
the addition
or removal of acethyl and methyl group and many other markers, helps the brain cells to reply and conform to all the environmental aggressions.
It has been discovered, in fact, that many molecular mechanisms by which the environment alters the genes’ comportment do not modify the information they contain. Thus, the epigenetic modifications provoked by the environment to the human body do not change the gene, but may modify its programmed activity.
The consequential epigenetic
modifications of the genes are due in fact, to a series of enzymes, some of which stick the chemical labels to the DNA’s histones (special proteins) while others erase them. Consequently, some enzymes write the information (stick the label) while others erase them. Therefore, the environment may influence the genes’ activity, controlling the comportment of
Chitin OH NH-CO-CH2 2500 O OH NH-CO-CH2 Chitin O glucosamine Acethyl
OH O CH2 OH glucosamine OH NH2 2500 Acethyl O O
CH2
OH O Glucosamine
Chitin nanofibril
Active compound Positive charged
Stabiliser (tenside) High speed stirrer
Homogenisation Filtration
Polyanionic HA Negative charged
Stabiliser (tenside)
Water washing Spray drying Nanoparticles Analysis
Figure 4: Production of CN block-polymer-nanoparticles.
Figure 5: Skin penetrability through the stratum corneum depends on electrical charges of nanoparticles and their size.
April 2012 PERSONAL CARE 97
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