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DOI: 10.1055/s-0034-1367270
Combined non-thrombogenic and endothelial cell adhesive surfaces by a single step procedure
Objectives: Blood contacting devices are prone to platelet adhesion and activation of the coagulation cascade resulting in potentially fatal thrombosis and emboli. Consequently a non-thrombogenic surface is desirable, what can be created by attaching highly hydrophilic polymers - eg. polyethylenglycol (PEG) - or by enabling endothelialization. Utilizing a conjugate consisting of a titanium (Ti) recognizing peptide motif coupled to the endothelial cell (EC) specific adhesive peptide REDV via a PEG-spacer, we intended to promote EC growth on Ti while simultaneously reducing platelet adhesion.
Methods: The peptide-PEG conjugate was synthesized by standard solid phase synthesis.
Ti samples were treated with the conjugate solution for 2 h. Untreated as well as modified specimen (n = 3) were seeded with 105 ECs per sample and growth was monitored after 4d by Calcein staining and fluorescent microscopy. In addition, samples were incubated in platelet rich plasma for 45 min, stained and examined. Micrographs were analyzed using ImageJ software and data expressed as mean ± sd.
Results: Bare Ti was poorly colonized by ECs after 4d (1.7 ± 1.06% coverage of total area) whereas modified material performed much better (25 ± 2.6%). Thrombocyte adhesion on treated surfaces was drastically reduced by a factor of approximately 14.4 compared to the control (91 ± 15.6 platelets/mm2 on modified Ti and 1309 ± 211 platelets/mm2 on untreated Ti respectively).
Conclusions: In a simple one-step procedure Ti surfaces can be endowed with EC adhesive properties while simultaneously reducing platelet attachment. The concept of PEGylated material-recognizing peptides, additionally functionalized with bioactive molecules can easily be translated to further cardio-vascular applications.
Fig. 1: TibP-PEG-REDV