Physical biocompatibility enhancement of fully biodegradable polymers for cardiovascular scaffolds

What is it about?

We determined the optimal surface topography (microgroove‐pattern) able to favor endothelialization on a PEG‐functionalized poly‐l‐lactide (PLLA‐PEG550, a highly promising, controllable and adaptable approach for enhancing the degradation rate of PLLA to the requirements of the bio‐resorbable stent application) using the direct, contactless and versatile method of picosecond laser patterning. Laser direct ablation with ultra‐short pulses (femtosecond and picosecond pulses) has emerged as a fast, precise and direct method for 3D micro‐structuring of a wide variety of substrates and geometries. A commitment can be reached by applying picosecond laser pulses to ensure enough precision and quality in feature generation at the microscale without negative impact in the process scalability. A series of in vitro cell culture tests were conducted with these laser‐patterned biodegradable PLLA‐PEG550 samples to thoroughly evaluate cyto‐ and hemocompatibility. While the focus of this study was the analysis of endothelialization potential using human-derived cardiovascular endothelial cells we also analyzed other biocompatibility properties: in addition to simple cytotoxicity and hemolysis analyses as required by ISO 10993–4 and −5 platelet adhesion as well as leucocyte activation were studied.

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Why is it important?

Ultrashort pulsed laser (USPL)-generated defined surface patterns on biodegradable polymer surfaces promote endothelial cell adhesion and elongation, emulating biomechanical effects that blood flow has in vivo. The USPL technology is easily applicable to other materials, i.e. metals. A stainless steel extrusion mandrel with specific endothelialization promotor pattern in combination with extrusion technologies can be used to manufacture artificial vascular implants of any size, but in particular temporary cardiovascular stents.

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