Thromb Haemost 2004; 92(06): 1394-1401
DOI: 10.1160/TH04-02-0124
Platelets and Blood Cells
Schattauer GmbH

Platelet deposition on stainless steel, spiral, and braided polylactide stents

A comparative study
Eeva-Maija Hietala
1   Helsinki University Hospital, Departments of Surgery and
,
Paula Maasilta
2   Medicine, and
,
Hanne Juuti
3   Institute of Biomaterials,Tampere, Finland
,
Juha-Pekka Nuutinen
3   Institute of Biomaterials,Tampere, Finland
,
Ari L. J. Harjula
1   Helsinki University Hospital, Departments of Surgery and
,
Ulla-Stina Salminen
1   Helsinki University Hospital, Departments of Surgery and
,
Riitta Lassila
4   Hematology, Helsinki, Finland
5   Wihuri Research Institute, Helsinki, Finland
› Institutsangaben

Financial support: This work has been supported by research grants from the Helsinki University Central Hospital Special Funds, the Finnish Cultural Foundation, and the Finnish Foundation for Cardiovascular Research.
Weitere Informationen

Publikationsverlauf

Received 25. Februar 2004

Accepted after resubmission 13. September 2004

Publikationsdatum:
04. Dezember 2017 (online)

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Summary

Platelets play a key role in (sub)acute thrombotic occlusion after stenting. We examined the possible differences between biodegradable polylactide (PLA) and stainless steel (SS) stents in platelet attachment and morphology after whole blood perfusion. PLA stents of different configurations (spiral/braided) and polycaprolactone-polylactide (PCL-PLA)-coatings, or SS stents were implanted into a PVC tube (Ø 3.2 mm), with or without precoating of the tube with type-I collagen. PPACK (30 µM)-anticoagulated blood with 3H-serotonin prelabeled platelets was perfused (flow rate: 30 ml/min, 90 s) over the stents. Platelet deposition was assessed by scintillation counting and morphology by scanning electron microscopy (SEM). To examine coagulation activation, plasma prothrombin fragments (F1+2) were measured before and after the perfusion. Protein deposition on PLA/SS stents was assessed at augmented shear forces mimicking coronary flow (rate: 60 ml/min, 60 s) under minimal anticoagulation (PPACK 1 µM). More platelets deposited on PLA stents than on SS stents under all study conditions (p <0.03). Under anticoagulation (PPACK 30 µM) the generation of F1+2 remained unaltered. Under higher flow rate and limited anticoagulation SS stents accumulated 3.27 ± 0.75 µg and PLA stents 5.25 ± 1.74 µg of protein (Mean ± SD, p <0.95). Among all biodegradable stents, the braided PLA stent coated with PCL-PLA-heparin accumulated the fewest platelets (p <0.02). In SEM, signs of platelet activation on braided heparin-coated PLA stents, when compared with uncoated braided PLA/SS stents, appeared modest. In conclusion, PCL-PLAheparin coating of biodegradable stents may enhance their hemocompatibility, expressed by less platelet deposition. Nevertheless, materials, design, and coating techniques of biodegradable stents must be further developed.