Platelet adhesion to novel phospholipid materials: Modified phosphatidylcholine covalently immobilized to silica, polypropylene, and PTFE materials

Abstract

Based on the premise of achieving blood compatibility through mimicking the chemical constitutents of the biologically insert surface of the unactivated platelet membrane, a process was developed that entails the covalent grafting of modified phosphatidylcholine molecules to materials including silica, polypropylene, and polytetrafluoroethylene (PTFE) polymer films. These materials were characterized using x-ray photoelectron spectroscopy (XPS) and contactangle measurements. The phosphatidylcholine-containing materials (PC materials) were used as substrates in the plateletadhesion assays and were subjected to enzymatic degradation evaluation. Phosphatidylcholine-grafted silica materials do not support platelet adhesion. In addition the number of adherent platelets correlate with the amount of grafted phospholipid present, as indicated by the phosphorus/ carbon ratio obtained by XPS analysis. Platelet adhesion to phosphatidylcholine-grafted polypropylene and PTFE was inhibited 80% and 90%, respectively, when compared with platelet adhesion to unmodified polypropylene and PTFE.

Glutardialdehyde induced fluorescence technique (GIFT): A new method for the imaging of platelet adhesion on biomaterials

“…PP appeared, not surprisingly, as the most platelet attracting and activating material. The findings for platelet counts and spread area on PP are comparable to the results reported by Kö hler et al 7 In the presence of plasma proteins, the hydrophilic HEMA surface modification dramatically reduced platelet/material interactions, which is in accordance with Desai and Hubbell. 5 The additional heparin-grafting of PDLLA-HEMA further improved the surface reactivity with platelets.…”

“…18 GIFT omits the use of selective/specific antibodies, staining with e.g. coomassie brillant blue or labeling with either fluorescent substances like rhodamine phalloidine, mepacrine or acridine orange, 6,7,23,26 or radioactivity. 22 This reduces associated risks, laboratory costs, and preparation time.…”

“…A successful approach to improve the hemocompatibility of biomaterials is surface modification by covalent coupling with anticoagulants, 3,4 grafting with hydrogels, 5,6 or phospholipids. 7 The development of new or modified materials, intended for blood contact, necessitates accurate methods for detection and quantification of platelet/material interactions.…”

Development of an electrospray approach to deposit complex molecules on plasma modified surfaces

“…32 Whole blood was obtained from normal donors and collected into acid citrate dextrose. Citrated blood was centrifuged at 800 rpm for 20 min at room temperature.…”

Bioinspired interface for nanobiodevices based on phospholipid polymer chemistry

“…Blood compatibility was assessed in a baboon arteriovenous shunt model, which revealed minimal platelet deposition over observation for 2 hours. Kohler et al (1996) prepared a glass surface that reacted with 3-aminopropyltrimethoxysilane (APTMS).…”