An in vitro study of blood compatibility of vascular grafts made of bacterial cellulose in comparison with conventionally-used graft materials.

In this study we analyzed the blood compatibility of bacterial cellulose (BC) as a new biosynthetic material for use as a vascular graft. As reference materials we used expanded polytetrafluoroethylene (ePTFE) and poly(ethylene terephthalate) (PET) vascular grafts. These materials are in clinical use today.

Real-time measurements of coagulation on bacterial cellulose and conventional vascular graft materials.

The search for a functional, small diameter (<5mm) vascular graft has been ongoing for over 30 years, but yet there is no consistently reliable synthetic graft. The primary mechanisms of graft failure are intimal hyperplasia, poor blood flow and surface thrombogenicity. Bacterial cellulose (BC) became therefore a proposed new biosynthetic vascular graft material.

Fibrinogen adsorption and conformational change on model polymers: novel aspects of mutual molecular rearrangement.

By combining quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR), the organic mass, water content, and corresponding protein film structure of fibrinogen adsorbed to acrylic polymeric substrates with varying polymer chain flexibility was investigated. Albumin and immunoglobulin G were included as reference proteins. For fibrinogen, the QCM-D model resulted in decreased adsorbed mass with increased polymer chain flexibility.

Quartz crystal microbalance-with dissipation monitoring (QCM-D) for real time measurements of blood coagulation density and immune complement activation on artificial surfaces.

A recently developed variant of quartz crystal microbalance (QCM) called QCM-with dissipation monitoring (QCM-D) allows simultaneous and simple measurements of changes in adsorbed mass as well as the viscoelastic property (D-factor) of deposited protein layers on the sensor surface. We have taken the QCM-D technology a step further and demonstrated its advantages in the study of protein assembly as a consequence of surface induced immune complement activation, or contact activated blood coagulation. In the present study we have continued our QCM-D investigations of surface assembly of fibrin clot formation and complement activation and incubated differently modified quartz sensor surfaces in blood plasma and sera.

Immune complement activation on polystyrene and silicon dioxide surfaces. Impact of reversible IgG adsorption.

We have studied aspects of the molecular background to immune complement activation on solid surfaces. Quartz crystal microbalance with dissipation monitoring (QCM-D) sensor surfaces were modified by means of spin coating with polystyrene (PS) or sputtering of silicon dioxide (SiO2). The IC activation on modified QCM-D surfaces was investigated by incubation in serum, followed by determinations of the amounts of bound C3 fragments (C3c) at the surface.

The effect of substrate molecular mobility on surface induced immune complement activation and blood plasma coagulation.

Changing the length of the alkyl ester side chain in poly(alkyl methacrylates) provides a unique opportunity to systematically vary the mobility of the polymer chains, or in other words vary the glass transition temperature (T(g)), without greatly affect the solid surface energy (gamma(s)) of the polymer. A series of poly(alkyl methacrylate) coatings was therefore analysed with regard to the human immune complement (IC) activation and the surface associated blood plasma coagulation cascade (CC) properties. For the IC and CC measurements we used a quartz crystal microbalance (QCM) where we modified the chemistry of the sensor surface by applying 10-30 nm thick poly(alkyl methacrylate) coatings.

Acoustics of blood plasma on solid surfaces.

We have quantified surface associated coagulation of human blood plasma with a recently developed methodological system consisting of a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), a method that measures the weight of adsorbed molecules on surfaces as a function of frequency shifts of a quartz crystal. Further, it measures the damping energy (i.e.