Development of Novel Material Surfaces for Cardiovascular Implants Using Direct Laser Interference Patterning

Background: The use of cardiovascular implants, such as stents, valves, closure devices, and the use of assist devices has reduced morbidity in patients with cardiovascular diseases. However, blood and tissue interaction with artificial surfaces is still challenging and limits the long-term use of such devices. Modification of the implant surface using ultra-short pulsed Direct Laser Interference Patterning (DLIP), without coating approaches, may influence the blood and cardiovascular tissue interaction with artificial surfaces of different implants. The study aimed to design nano-structured surfaces using the DLIP method and to test their suitability for cardiovascular implants using cardiovascular cell lines in vitro.

Methods: For this purpose, ultra-short pulsed Direct Laser Interference Patterning (DLIP) was used to create periodic line structures of 10 µm, 3 µm, and 750 nm. In addition, parallel (p) and perpendicular (s) substructures were generated by varying the beam polarization for 10 µm and 3 µm main structures. The biocompatibility of these structures was investigated using an HCM cell line (human cardiac myocytes). After 1, 3, and 6 days of culturing changes in morphology, metabolic rate, or cell death were evaluated and compared with polished control surfaces. Cell morphology was visualized by immunofluorescence staining. Viability assays including WST1 and BrdU were performed to analyze the metabolic activity and cell proliferation. The rate of dead cells was determined by Life/Dead staining.

Results: The 3 µm and 10 µm structures induced guided growth of cardiomyocytes along the line structures. Compared with polished control surfaces proliferation of cells was decreased on 3 µm and 10 µm structures. The 750 nm structure did not evoked such effects in cell culture. None of the tested structures showed cytotoxic effects on cells but caused decreased metabolism.

Conclusion: The structure of the designed surfaces can control the myocardial cell's behavior and growth. These surfaces exhibit considerable potential for usage for cardiovascular implants. Further testing of the new surfaces with other cell lines in vitro and blood interaction ex vivo is planned.

Publication History

Article published online:
13 February 2024