Plasma Protein Adsorption and Platelet Adhesion on Heparin-Immobilized Polyurethane Films

Abstract

Polyurethane surfaces were modified by covalent immobilization of different molecular weight heparins (fractionated Mw $3000 Da, and unfractionated Mw $17,000-19,000 Da) and examined by ESCA, AFM, and contact angle goniometer. The effect of these different surface-immobilized heparins on blood protein adsorption and on platelet adhesion, were examined after incubating the samples with platelet-poor and platelet-rich plasma. Protein adsorption kinetics was studied by electrophoresis and the platelets adhered on the surfaces were examined by SEM after incubation. The two heparin types clearly showed different behavior with respect to protein adsorption, especially in the early stages of blood plasma interaction. After a 5-min incubation in plasma, low molecular weight heparin-immobilized polyurethanes (PU-LMWH) showed three times less protein adsorption compared to unfractionated heparinimmobilized polyurethanes (PU-UFH). The total amount of adhered protein Downloaded from became more similar as the incubation time was extended. The morphology of adhered platelets on material surfaces demonstrated differences: PU-UFH had clusters with some pseudopodia extensions, while PU-LMWH surfaces had roundshaped platelets with little clustering. For contact times 415 min, the amount of adsorbed proteins and adhered platelets on the heparinized PU surfaces decreased.

Hyaluronan and dextran modified tubes resist cellular activation with blood contact

“…In these cases the platelets appeared to have much less spreading on the surface with far fewer pseudopod extensions than on the most adhesion-stimulating materials studied, as has also been noted previously for platelet-resistant biomaterials [12]. This analysis is also consistent with findings reported in other studies of platelet adhesion to selectively coated PU and PVC surfaces [1;2;12;36]. …”

Protein adsorption, platelet adhesion, and bacterial adhesion to polyethylene-glycol-textured polyurethane biomaterial surfaces

“…The traditional strategy for controlling biological responses by surface modification is through chemical or physical designs. One effective chemical approach is grafting, which places polymerized monomers or covalently couples existing polymer molecules onto the polymer surface .…”

“…5,6 Modification of biomaterial surfaces represents a promising route to engineer biofunctionality at material-blood interfaces enhancing the biocompatibility and antibacterial properties without altering the bulk property of biomaterials. 7,8 The traditional strategy for controlling biological responses by surface modification is through chemical [9][10][11][12][13][14] or physical [15][16][17] designs. One effective chemical approach is grafting, which places polymerized monomers or covalently couples existing polymer molecules onto the polymer surface.…”

Modulation of collagen and keratin synthesis in co-cultures of fibroblasts and keratinocytes on hyaluronan-coated polysulfone membranes

“…Very often, these materials were modified by immobilizing the matrix macromolecules, such as heparin and hyaluronic acid (HA), in order to improve their functionality. [1][2][3][4][5][6][7][8][9] In previous studies, we found that both PSU and HA-coated PSU membranes were suitable for culturing dermal fibroblasts and to support their matrix synthesis capacity. 10,11 Furthermore, they induce the expression of type III collagen in addition to type I, indicating that they promote a fetal-like environment that could be beneficial for enhanced wound healing.…”