Devido à composição química, o biodiesel é muito suscetível à oxidação, tornando necessária a adição de antioxidantes que inibem ou retardam esse processo. Entretanto os antioxidantes ficam expostos à condições que podem degradá-los, reduzindo sua eficiência. Dessa forma, o uso de nanoesferas (NE) surge como alternativa para proporcionar a proteção dos mesmos. Neste sentido, o objetivo deste trabalho foi desenvolver NE de poli-ɛ-caprolactona contendo o antioxidante terc-butil-hidroquinona e aplicá-las no biodiesel. O método utilizado na produção das NE foi emulsificação-evaporação do solvente e a estabilidade foi avaliada durante 31 dias na estufa à 30°C, sendo analisados o tamanho, polidispersão, potencial zeta, atividade antioxidante e pH durante o período estudado, além da avaliação do tempo de indução do biodiesel contendo as NE. Após o período analisado, as NE sofreram variações estatisticamente significativas no pH (6,20 para 7,63), potencial zeta (-12,50 mV para-13,83 mV) e a atividade antioxidante (84,4 para 51%). Quanto ao TI, a adição das NE ao biodiesel não resultou em variações significativas.
Background:
Alzheimer's disease (AD) is a neurodegenerative disease characterized by the
progressive and incapacitating decay of cognitive, neuropsychiatric, and behavioral manifestations.
L-tryptophan is the precursor amino acid of serotonin, which is a neurotransmitter responsible for
mood balance and the sense of well-being and can be administered in the form of nanoparticles.
Objective:
This study analyzed the effectiveness of L-tryptophan nanoparticles and L-tryptophan on
behavioral physiological alterations resulting from AD in animal models.
Methods:
The sample consisted of 50 Rattus norvegicus rats, divided in 10 groups with 5 animals
each: one negative control (NC), three positive control groups (C3, C7, and C21), three groups treated
with L-tryptophan nanoparticles (T3N, T7N, and T21N) at the concentration of 1.5 mg, and three
groups treated with L-tryptophan (T3L, T7L, and T21L) at the concentration of 1.5 mg. The rats underwent
stereotactic surgery to induce AD through the injection of amyloid beta-amyloid peptide1-42 in
the intracerebroventricular region. All rats were submitted to pre- and post-surgery and post-treatment
motor behavior evaluation through the Later Water Maze (LWM) and elevated cross-labyrinth (ECL).
Histological analysis was performed to verify the presence of senile plaques, and the statistical analysis
used the unpaired T-test.
Results:
Significant intergroup differences were observed in some of the evaluated parameters between
treated and untreated groups.
Conclusion:
It was concluded that the treatment with L-tryptophan nanoparticles was beneficial to
improve behavioral reactions in the Alzheimer's model.
Objective:
Atorvastatin (ATV) is effective in reducing total cholesterol and low-density lipoprotein
levels. Furthermore, it produces pleiotropic effects in neurodegenerative conditions such as
Parkinson's, Alzheimer's, and epilepsy. However, due to the effective defense system of the central
nervous system (CNS), the development of new medicines for clinical conditions has proven difficult.
In this context, nanotechnology was applied as a promising solution to promote drug vectorization to
the brain.
Methods:
The solvent emulsification-diffusion method was used to develop nanoparticles (NPs) based
on polylactic acid and coated with polysorbate 80 containing ATV. Quality-by-Design (QbD) was
used in the optimization of nanoparticles production through the application of the experimental design
Box-Behnken Design.
Results:
After optimizing the independent factors including sonication time, surfactant concentration
and surfactant volume, the NPs presented physicochemical characteristics such as entrapment efficiency
of 86.4 ± 2.4%, mean size of 225.2 ± 4.8 nm, and zeta potential of -14.4 ± 0.36 mV. In the in vitro
release study, approximately 20% of the encapsulated ATV was released.
Conclusion:
The application of QbD was very useful in demonstrating its applicability in the nanotechnological
pharmaceutical area for controlling and predicting the influence of the variables in the
production of NPs. The NPs developed in this study presented adequate physicochemical characteristics,
which is promising for future in vivo studies.
Conclusion:
The physicochemical characteristics included entrapment efficiency of 86.4 ± 2.4%, mean size of
225.2 ± 4.8 nm, and zeta potential of -14.4 ± 0.36 mV. In the in vitro release study, approximately
20% of the encapsulated ATV was released. The application of QbD was very useful in demonstrating
its applicability in the nanotechnological pharmaceutical area for controlling and predicting the influence
of the variables in the production of NPs. The NPs developed in this study presented adequate
physicochemical characteristics, which is promising for future in vivo studies.
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