Hemocompatibility of chitosan/poly(acrylic acid) grafted polyurethane tubing

Abstract

The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tubes upon exposure to saline solution for 7 days. Using quartz-crystal microbalances with dissipation (QCM-D), in-situ adsorption of blood plasma proteins on CH and CH-Q compared to a silicon oxide control was measured. The QCM-D results showed that the physically adsorbed plasma protein layer on CH-Q and CH surfaces is softer and more viscous than the protein layer on the SiO2 surface. The CH-Q layer thus has the weakest interaction with plasma proteins. Whole blood and platelet adhesion was reduced by ~92% on CH-Q, which showed the weakest interaction with plasma protein but more viscous adsorbed plasma protein layer, compared to SiO2. Last, to examine the biologic response of platelets and neutrophils to biomaterial surfaces, CH (CH-Q)/PAA, PAA and PU tubes were tested using a Chandler Loop apparatus as an ex vivo model and flow cytometry. The blood adhesion and biologic response results showed that CH and CH-Q reduced adhesion and activation of platelets and neutrophils and improved hemocompatibility relative to other surfaces (PU and PAA). Our studies demonstrated that the properties of physically adsorbed plasma protein layer on biomaterial surfaces correlates with blood coagulation on biomaterial surfaces.

Targeted Release of Tobramycin from a pH-Responsive Grafted Bilayer Challenged with S. aureus

“…In addition, PAA coated PU (PAA/PU) and CH grafted PAA/PU (CH/PAA/PU) tubes were prepared using previously published methods. 60 …”

“…Figure 1B shows the bilayer construction with the end-grafted PAA brush (red) cross-linked to the outer CH (blue), respectively. CH is a natural polymer that inhibits blood coagulation and inflammatory response upon blood contact (i.e., biocompatible) 60,61 and resists the attachment of bacteria. 68–70 Chitosan is insoluble at pH 7 and therefore forms a glassy outer layer under physiological conditions.…”

Chemically grafted fibronectin for use in QCM-D cell studies

“…Advances in medical device surface modification include our group’s recent work on the antibacterial properties and hemocompatibility of grafted surfaces (Coll Ferrer et al, 2013; Dastgheyb et al, 2013; Eckmann et al, 2013; Lee et al, 2013a, 2013b), with many other new developments reviewed by (Campoccia et al, 2013) and (Meyers and Grinstaff, 2012). Emerging technologies in biological research also often require the grafting of biomaterials, including various protein coatings to enable cell and biomolecule attachment in microfluidic devices (Shirtcliffe et al, 2013) and even the immobilization of enzymes for biocatalysis performance (Jia et al, 2014).…”

Surface modification strategies to improve titanium hemocompatibility: a comprehensive review

“…Modifying the device surface is effective because it can prevent the blood reactions without altering the favorable bulk material properties. 39 …”

“…Modifying the device's surface is effective because it can prevent the blood reactions without altering the favorable bulk material properties. 39 Fig. 3: Schematic representation of medical device associated thrombosis.…”