Identificação e avaliação de propriedades de polissacarídeos sulfatados de diferentes fontes naturais que possibilitem sua aplicabilidade biotecnológica
Sulfated polysaccharides (SP) are widely distributed in animals and seaweeds tissues. These polymers have been studied in light of their important pharmacological activities, such as anticoagulant, antioxidant, antitumoral, anti-inflammatory, and antiviral properties. On other hand, SP potential...
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| Formato: | doctoralThesis |
| Idioma: | por |
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Universidade Federal do Rio Grande do Norte
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| Endereço do item: | https://repositorio.ufrn.br/jspui/handle/123456789/13241 |
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| Resumo: | Sulfated polysaccharides (SP) are widely distributed in animals and seaweeds
tissues. These polymers have been studied in light of their important pharmacological
activities, such as anticoagulant, antioxidant, antitumoral, anti-inflammatory, and
antiviral properties. On other hand, SP potential to synthesize biomaterials like as
nanoparticules has not yet been explored. In addition, to date, SP have only been found
in six plants and all inhabit saline environments. However, the SP pharmacological plant
activities have not been carrying out. Furthermore, there are no reports of SP in
freshwater plants. Thus, do SP from marine plants show pharmacological activity? Do
freshwater plants actually synthesize SP? Is it possible to synthesize nanoparticles
using SP from seaweed? In order to understand this question, this Thesis was divided
into tree chapters. In the first chapter a sulfated polysaccharide (SPSG) was
successfully isolated from marine plant Halodule wrightii. The data presented here
showed that the SPSG is a 11 kDa sulfated heterogalactan contains glucose and
xylose. Several assays suggested that the SPSG possessed remarkable antioxidant
properties in different in vitro assays and an outstanding anticoagulant activity 2.5-fold
higher than that of heparin Clexane® in the aPTT test; in the next chapter using
different tools such as chemical and histological analyses, energy-dispersive X-ray
analysis (EDXA), gel electrophoresis and infra-red spectroscopy we confirm the
presence of sulfated polysaccharides in freshwater plants for the first time. Moreover,
we also demonstrate that SP extracted from E. crassipes root has potential as an
anticoagulant compound; and in last chapter a fucan, a sulfated polysaccharide,
extracted from the brown seaweed was chemically modified by grafting hexadecylamine
to the polymer hydrophilic backbone. The resulting modified material (SNFuc) formed
nanosized particles. The degree of substitution for hydrophobic chains of 1H NMR was
approximately 93%. SNFfuc-TBa125 in aqueous media had a mean diameter of 123 nm
and zeta potential of -38.3 ± 0.74 mV, measured bydynamic light scattering. Tumor-cell
(HepG2, 786, H-S5) proliferation was inhibited by 2.0 43.7% at SNFuc concentrations
of 0.05 0.5 mg/ mL and RAEC non-tumor cell line proliferation displayed inhibition of
8.0 22.0%. On the other hand, nanogel improved CHO and RAW non-tumor cell line
proliferation in the same concentration range. Flow cytometric analysis revealed that
this fucan nanogel inhibited 786 cell proliferation through caspase and caspaseindependent
mechanisms. In addition, SNFuc blocks 786 cell passages in the S and
G2-M phases of the cell cycle |
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