Laser ablation patterning by interference induces directional cell growth

Laser-patterning by interference is a method to introduce micropatterns on the surface of TXL and TXB, which were shown to have an effect on the L929 growth. In this experiment, we have produced collagen-coated and laser-patterned TXL and TXB with different dimensions; the groove width of the line patterns varied approximately from 1.2 μm to 9.7 μm, ridge depth varied from 0.4 μm to 1.3 μm, and the groove depth varied between 0.4 μm and 1.3 μm. Therefore, a homogeneous smooth surface was achieved, and that L929 growth was only affected by the different dimensions of the line patterns. All the laser-patterned TXL and TXB have shown inducing different degrees of directional growth of L929 that the cells grew in the direction aligning the microgrooves. However, the different widths of the microgrooves were demonstrated to play an important role in determining cell morphology and growth orientation. For example, cells were elongated when they grew on the narrower widths, which were 1.26 μm, 1.91 μm, and 5.04 μm while cells tended to be triangular when grew on wider width about 9.76 μm. In addition, L929 might grow only on the top of the laser-patterns attaching the ridges when the groove widths were narrow, but might grow into the microgrooves when the width went beyond 5.04 μm.