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العنوان
The Possible Impact of Zinc on the Bioaccumulation
and Lethality of Nano-aluminum Oxide Particles in
Rats /
المؤلف
Abd Eldayem, Hoda Khaled Khaled.
هيئة الاعداد
باحث / هدى خالد خالد عبد الدايم
مشرف / أحمد رفعت محمود عزت
مشرف / جمال محمد مرسى منصور
تاريخ النشر
2021.
عدد الصفحات
138 P. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
علم الحيوان والطب البيطري
تاريخ الإجازة
1/1/2021
مكان الإجازة
جامعة عين شمس - كلية العلوم - قسم علم الحيوان
الفهرس
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Abstract

The toxicity of nanoalumina (Al2O3NPs) as a result of
accumulation in the tissues of living organisms has been
recognized since the last decades of the twentieth centuries. It has
been found that zinc, as bulk zinc salt, acts to encounter the
accumulation of aluminum ions, due to its chemical interaction
with this metal, and this gives zinc an excellent therapeutic
potentials to counteract and possibly lessen its notorious toxicity.
Nanomaterials, because of their physical and chemical properties,
have a substantial ability to penetrate the biological membranes,
including cell membrane, blood-brain, and testicle barriers among
many others in living organisms. Nanoparticles, in general, are
more capable of gradual accumulation inside the cells and vital
organelles where they are retained until they reach concentrations
sufficient to induce sever cellular toxicity. Accordingly, the
hypothesis of this study is based on the rationale that nano-zinc
oxide (ZnONPs) particles, with their presumably high penetration
and accumulation capacity would be even more efficient in
encountering the aluminum nanoparticles toxicity. To the author’s
knowledge, and after thorough literature search, there is no
mention of previous studies to evaluate the interactions between
Al oxide nanoparticles with either nano-zinc or bulk zinc in
mammalian tissues. This work attempts, for the first time, to
compare and provide a full coverage of the bioaccumulation
pattern of aluminum nanoparticles in tissues in the presence of
nano-zinc oxide and bulk zinc chloride in attempt to evaluate their
ameliorative potentials in precluding the accumulation of
Al2O3NPs in various rat organ.
To attain the objectives set for this work, the following
parameters were computed and assessed; the lethality percentile
doses, including the median lethal dose of Al2O3NPs at 24h, acute
bioaccumulation of Al in different tissues, and the effect of
[90]
combined treatment of nano alumina with either nano- or bulk zinc
after 24 h. A follow-up study with sub-acute experiments, which
covered several time intervals extending to 21 days, was also
performed. In addition, the nano-size and zeta potential of
Al2O3NPs and ZnONPs were estimated. The TEM technique
revealed the amorphous shape of the Al2O3NPs with a size average
of 8.26 ± 1.987 nm whereas that of ZnONPs had a crystal shape
with an average diameter of 35.71 ± 5.39nm. The Zeta potential
for Al2O3NPs and ZnONPs was 43.8 mV and 34.1 mV
respectively. In order to determine the acute and sub-acute doses
of Al2O3NPs, ZnONPs, and B-ZnCl2, the lethality percentile
dosages (LD1 to LD99) were estimated.
In order to evaluate the influence of zinc, as Nano- or bulk
zinc, during acute and sub-acute experimentation, on the
bioaccumulation of Al2O3NPs, the following design was
constructed. For the acute experiments, rats were divided into four
groups. The first group was intranasally instilled with deionized
water (group I), whereas those of groups II, III, and IV were
instilled with a single acute dose of LD25@96h Al2O3NPs either
alone (1.66 g/kg b. wt.), in combination with ZnONPs LD25@96h
(0.52 g/kg b. wt.), or with B-ZnCl2 LD25@96h (0.06 g/kg b. wt.),
respectively. The total sample size was estimated as twenty rats
(N=20) which were then divided into four equal groups, each of
five rats (n=5). For the sub-acute experiments, the total sample
size of one-hundred rats (N=100) was allocated into four groups
of V, VI, VII, and VIII, each of twenty-five rats. The first group
was intranasally instilled with deionized water (group V), whereas
the sixth to the eighth groups, were instilled with a sub-acute dose
of LD5@96h Al2O3NPs alone (0.94 g), every other day, and in
combination with a sub-acute dose of LD5@96h ZnONPs (0.18g) or
the LD5@96h B-ZnCl2 (0.03g), respectively. In sub-acute
experimentation, five rats were taken from each group after 1, 3,
[91]
7, 14, and 21 days, euthanized and quickly dissected. The brain,
liver, kidneys, heart, spleen, and lungs were excised and prepared
for the metal assay. Aluminum ion content was measured
according to Smichowski et al. (2005) with the aid of an
Inductively Coupled Plasma Atomic Emission Spectrometer (ICPAES). The Al levels were expressed as µg/g dry wt. Statistically,
the Kolmogorov-Smirnov test indicated that the present data was
normally distributed, and therefore the parametric statistical
analyses were used. Two-ways analysis of variances was applied
to analyze the effect of nano- and bulk zinc on the LD50@24h of
Al2O3NPs as well as the bioaccumulation of Al in the studied
tissues, and their interactions during acute experimentation. In the
sub-acute experiments, one-way ANOVA was applied to analyze
the effect of the experimental periods (1, 3, 7, 14, and 21 days) on
the accumulation of Al in each organ, followed by Duncan’s
multiple range test (DMRT) and Tukey’s test post ANOVA hoc
analysis. Regression analysis and Spearman’s correlation
coefficient (r) were used to fit the relationships between the
different studied variables. All the results were expressed as a
mean ± standard error of the mean (SEM).
The current results revealed that the B-ZnCl2 was more toxic than
ZnONPs and Al2O3NPs, and this was indicated by its lethality
percentile dosages that were greater than ZnONPs and Al2O3NPs.
Additionally, the B-ZnCl2 and ZnONPs had a high affinity to
increase the median lethal dose values of Al2O3NPs at 24h, and
this confirmed that zinc reduces the nano alumina lethality. In
other words, the average values of the median lethal dose at 24h
(LD50@24h) of nano alumina were increased in response to both
forms of zinc salts at 24, 48, 72, and 96 h. These results revealed
their capability to reduce the Al2O3NPs lethality.
In conclusion, either the nano- or the bulk zinc had the
ability to reduce the bioaccumulation of Al inside the cells and
[92]
their organelles as reflected by the increased average values of the
lethality percentile dosages of nano alumina. Accordingly, the
potential full lethality of nano alumina is reduced which may help
in reducing the notorious impact of their accumulation in living
tissues. The statistical analysis revealed that ZnONPs are more
efficient than B-ZnCl2 in diminishing the bioaccumulation and
lethality of Al2O3NPs, thereby reducing their toxicity