2 Multifunctional Magnetic Nanocomposites on the Base of Magnetite. . .
41
It was found that an increase in an equilibrium concentration of DR does not
lead to a saturated adsorption of the surface of the Fe 3 O 4 /H£ adsorbent. It was
discovered that the release of DR into saline solution has been decreasing as its
quantity on the NC surface has been increasing.
Investigation of Bioactivity of Nanocomposites on the Basis of Doxorubicin
The biocompatibility of Fe 3 O 4 /H£ NC was studied in many works, for example,
in [2, 6, 7, 9, 11, 12, 17, 18, 22, 24, 37]. In works [2, 24, 39], the biocompatibility
and the bioactivity of the produced samples were controlled by their effect on the
viability of baking yeast cells Saccharomyces cerevisiae.
In works [19, 23, 35], the interaction of DR with baking yeast cells Saccharomyces cerevisiae was studied. In particular, the presence of a cytotoxic effect
of the antibiotic on the cells and a decrease in the rate of their proliferation were
found. The mentioned effects are typical of DR and are caused, in particular, by its
participation in cyclic redox reactions and a respective increase in the number of
molecules of free radicals, an induction of oxidative stress and delays in the cell
cycle in G 1 - and S-phases. However, we did not manage to find in scientific sources
the data related to the impact of magnetosensitive nanocomposites containing
doxorubicin on baking yeast cells Saccharomyces cerevisiae.
Therefore, of interest was the research aimed at studying a cytotoxic effect of
new magneto-controlled multifunctional NCs on the basis of single-domain Fe 3 O 4 ,
H£, and DR on Saccharomyces cerevisiae cells [39].
During the research of bioactivity of the input DR preparation, it was experimentally found that its solution in a physiological fluid of a concentration of
0.5 mg/ml leads to an almost total death of yeast cells (95%) within 3.5 days. In
the methodology of cytotoxicity determination, usually use a I´ 50 dose at which
the death of ∼50% of cells are observed [15]. That’s why for bioactivity testing
a quantity of nanocomposite material Fe 3 O 4 /H£/DR (∼20 mg) with immobilized
doxorubicin (∼50 mg/g) which is used to make a suspension was selected as per the
data of Fig. 18 and Table 2.2, to ensure that the concentration of released DR in the
tested suspensions is equal to ∼0.25 mg/ml.
In total five samples of each of the following series were tested:
1. Suspension of yeast cells (initial concentration n 0 ≈ 2.5·10 7 ml −1 ) in PF with
MSM (Fig. 2.6a)
2. Suspension of yeast cells (initial concentration n 0 ≈ 2.5·10 7 ml −1 ) in PF with
MSM containing 20 mg of Fe 3 O 4 /HA NC
3. Suspension of yeast cells (initial concentration n 0 ≈ 3.5·10 7 ml −1 ) in PF with
MSM containing 20 mg of Fe 3 O 4 /HA/DR NC
All the samples contained 1.3 ml of saline solution (0.9% NaCl) and 1 ml of
MSM. The samples of series 1 and 2 were used for control and comparison and of
series 3 – for research of bioactivity of Fe 3 O 4 /H£/DR NC.
The data analysis shows that in the yeast suspensions (n 0 ≈ 2.5·10 7 ml −1 ) in
PF with MSM (type 1 control series) a cell proliferation typical of yeast is seen,
which led to a twofold increase in their concentration within 16 h (to 5·10 7 ml −1 ).
41
It was found that an increase in an equilibrium concentration of DR does not
lead to a saturated adsorption of the surface of the Fe 3 O 4 /H£ adsorbent. It was
discovered that the release of DR into saline solution has been decreasing as its
quantity on the NC surface has been increasing.
Investigation of Bioactivity of Nanocomposites on the Basis of Doxorubicin
The biocompatibility of Fe 3 O 4 /H£ NC was studied in many works, for example,
in [2, 6, 7, 9, 11, 12, 17, 18, 22, 24, 37]. In works [2, 24, 39], the biocompatibility
and the bioactivity of the produced samples were controlled by their effect on the
viability of baking yeast cells Saccharomyces cerevisiae.
In works [19, 23, 35], the interaction of DR with baking yeast cells Saccharomyces cerevisiae was studied. In particular, the presence of a cytotoxic effect
of the antibiotic on the cells and a decrease in the rate of their proliferation were
found. The mentioned effects are typical of DR and are caused, in particular, by its
participation in cyclic redox reactions and a respective increase in the number of
molecules of free radicals, an induction of oxidative stress and delays in the cell
cycle in G 1 - and S-phases. However, we did not manage to find in scientific sources
the data related to the impact of magnetosensitive nanocomposites containing
doxorubicin on baking yeast cells Saccharomyces cerevisiae.
Therefore, of interest was the research aimed at studying a cytotoxic effect of
new magneto-controlled multifunctional NCs on the basis of single-domain Fe 3 O 4 ,
H£, and DR on Saccharomyces cerevisiae cells [39].
During the research of bioactivity of the input DR preparation, it was experimentally found that its solution in a physiological fluid of a concentration of
0.5 mg/ml leads to an almost total death of yeast cells (95%) within 3.5 days. In
the methodology of cytotoxicity determination, usually use a I´ 50 dose at which
the death of ∼50% of cells are observed [15]. That’s why for bioactivity testing
a quantity of nanocomposite material Fe 3 O 4 /H£/DR (∼20 mg) with immobilized
doxorubicin (∼50 mg/g) which is used to make a suspension was selected as per the
data of Fig. 18 and Table 2.2, to ensure that the concentration of released DR in the
tested suspensions is equal to ∼0.25 mg/ml.
In total five samples of each of the following series were tested:
1. Suspension of yeast cells (initial concentration n 0 ≈ 2.5·10 7 ml −1 ) in PF with
MSM (Fig. 2.6a)
2. Suspension of yeast cells (initial concentration n 0 ≈ 2.5·10 7 ml −1 ) in PF with
MSM containing 20 mg of Fe 3 O 4 /HA NC
3. Suspension of yeast cells (initial concentration n 0 ≈ 3.5·10 7 ml −1 ) in PF with
MSM containing 20 mg of Fe 3 O 4 /HA/DR NC
All the samples contained 1.3 ml of saline solution (0.9% NaCl) and 1 ml of
MSM. The samples of series 1 and 2 were used for control and comparison and of
series 3 – for research of bioactivity of Fe 3 O 4 /H£/DR NC.
The data analysis shows that in the yeast suspensions (n 0 ≈ 2.5·10 7 ml −1 ) in
PF with MSM (type 1 control series) a cell proliferation typical of yeast is seen,
which led to a twofold increase in their concentration within 16 h (to 5·10 7 ml −1 ).