Fig. 3: (A) The obtained viability of the MSCs cultured on the collagen
thin films with various concentrations after 48 h; (B) Results of
counting the number of MSCs on the collagen thin films with various
concentrations after 48 h. Symbol * represents statistically significant
between groups determined by ANOVA (p < 0.05).
Bioimpedance assessment of the collagen thin films
concentration on the MSCs proliferation rate
3.2.1 Bioimpedance magnitude of the MSCs cells cultured on the
collagen thin film
Fig. 4 (A-C) shows the magnitude diagram of the measured impedances of
the MSCs seeded on the collagen thin films with various concentrations
during the time. As shown in the diagram, the magnitude of the measured
differential bioimpedance () at different concentrations of collagen
thin films has increased over time. This increase in impedance can be
due to cell attachment and proliferation over time. The diagram of the
of the MSCs cultured on different concentrations of collagen thin films
after 48 h is shown in Fig. 5 (A). Results showed that after 48 h, when
the doubling time of the MSCs has elapsed, the amount of increase in
impedance at lower concentrations is higher than that of higher
concentrations, which may indicate more cell growth on the collagen thin
films with lower concentration. Previous studies have investigated the
relationship between the collagen thin films concentration and cell
proliferation and morphology [2]–[6], [8],
[40]. The cells that interact with fibrils formed from higher
concentrations of collagen solution do not spread much on the surface
and show a weaker cytoskeleton than the cells that interact with fibrils
formed from lower concentrations of the collagen thin films. The cells
on the surfaces prepared from low collagen concentrations have a higher
rate of proliferation and show variations in gene expression compared to
the cells on collagen with similar concentrations to the physiological
condition [41]. The important point of this
research is that we have concluded this result with a quantitative
impedance criterion. The same results obtained for HUVECs cells under
similar conditions, which will represent in the next section.