Research on Mammalian Cell Arrangement - "Mammalian Cell Arrangement on Nanostructured Tantalum Surface"

Table 1 Results of cell alignment performance on different substrate materials and surface pattern designs

As can be clearly seen in Table 1, the sensitivity of cell morphology and cell arrangement varies significantly between cell types and substrate materials as a result of surface pattern geometry (eg, line and trench width).

Table 2 Summary of data for the number of cells (n) examined

The horizontal axis is the percentage of cell population with 10♀>φ>10♀, and the axis length ratio (L/S). The initial cell concentration of the medium used was approximately 0.5 × 105 cells/ml. Data spread corresponds to one standard deviation.

Figure 1 Schematic showing the fabrication method of tantalum (green) comb-like structures

(a) The pattern is transferred onto the silicon oxide film using photolithographic techniques. (b) Deposition of tantalum and copper films on the etched pattern. (c) Use chemical mechanical polishing to remove excess copper. Strip the remaining copper with nitric acid. The comb-like structure contains lines (L) and grooves (T) of equal width. All trenches have the same depth (D).

Figure 2 Schematic diagram of the cells on the patterned comb-like structure and its orientation and elongation parameters

Figure 3 Representative top-down scanning electron microscope (SEM) micrographs

Different comb-like structures and adherent cells overlying tantalum (Ta) membranes are shown. The results showed that on structures with line widths of 0.18–10 μm, adherent cells were aligned with the spool. In contrast, cells on the 50-µm and 100-µm structures did not align well with the spools—they resembled cells randomly distributed on the covering tantalum membrane. All cells were incubated on these specimens for 24 hours.

Figure 4 Typical fluorescence confocal micrographs of adherent cells covered with tantalum films and comb-like structures

Line widths are 0.18, 10, and 50 μm; nuclei are in blue, while F-actin filaments are in red (fluorescent penis protein conjugate).

Fig. 5 Distribution of cell orientation (φ) percentage points at 0.18, 0.25, 0.5, 1, 2, 5, 10, 50

To quantify cell alignment and elongation behavior, the orientation of the nuclei relative to the spool (φ) and their dimensions were measured. Figure 5a shows the percentage of nuclei populations oriented at different angles to the spool. Samples with randomly oriented nuclei should have an equal distribution within each bin. The error bars shown in Figure 5a,b represent one standard deviation of the results for the three sets of random nuclei. shown in Figure 5c. The results showed that the nuclei were significantly elongated when cells adhered to the comb-like structures with line widths of 0.18–10 μm. shown in Figure 5d. The results showed that the average elongation of the nuclei also increased as more nuclei were aligned in a row axis.

Fig. 6 Scanning electron micrographs of the 70♀ line width of 0.18–50 μm in the cell tilt on the comb-like structure

Two distinct types of cell adhesion morphologies were observed: type 1 - adherent cells on 0.18 μm and 0.25 μm structures only contact the top of the wire but do not fill the groove gap, and type 2 - combs with wire widths greater than 1 m The cells on the like structures exhibit conformal surface coverage. Two morphological types of adherent cells were observed on 0.5 μm combs. All cells were incubated on the construct for 24 hours.

Fig. 7 Scanning electron microscope photo of 70♀ line width of slanted cross-section cells on the comb-like structure

(a) 0.18 μm, (b) 0.25 μm, and (c) 0.5 μm. Two distinct types of cell adhesion morphologies were observed: type 1 - adherent cells on the 0.18 μm and 0.25 μm structures only contact the top of the line but do not fill the groove gap; and type 2 - cells show conformal surface coverage. Two morphological types of adherent cells were observed on 0.5 μm combs. All cells were incubated on the construct for 24 hours. The cell concentration is approximately 5 × 105 cells/ml.