Guided orientation of human cardiomyocytes on laser patterned biphasic core/shell nanowires

Background: In contrast to other organ tissues myocardial tissues are contractile fibers, which have definitive orientation in order to achieve global mechanical contractile function and strain. Thus, guiding of myocytes adherence on micro and nano-structured surfaces is fundamental in order to develop such 3D-contractile heart tissues for possible regenerative therapy approaches. We test the effect of micro/nano-structured periodic lines on the direction and growth of human cardiomyocytes (HCM).

Methods: Prior to cell culture experiments, four different linear patterns with periodicity of 1, 2, 4 and 8 µm were prepared using Laser interference patterning. Cellular adhesion, viability and alignment of HCM have been investigated after cultivation on different laser patterned nanowires compared with unmodified nanowires. For visualization of the cytoskeleton and the focal adhesion points, the F-actin fibers of the cells as well as vinculin were stained.

Results: HCM on patterned surfaces exhibited an increased punctual adhesion over focal adhesion points but a changed arrangement. By altering the spacing of the linear structures, the cells started to align clearly along the direction of the micro-scale patterns. Cells on nanowires with 1 µm periodic lines showed a mixture of aligned and randomly grown cells. But with 2 µm periodic patterns the cells showed a strong alignment.

Conclusions: The laser induced scalability of the suggested surfaces enable a regular growing and orientation of myocardial tissues. Such approaches may be used to modify the surfaces of potential scaffolds to develop 3D-contractile tissues myocardial in the future.