Fibrinogen on glass

Figure 3. Adsorption of fibrinogen on glass as a function of time at various hematocrits. Conditions buffer—PBS, pH 7.35 fibrinogen concentration—1.0 mg/mL in free volume and shear rate at the surface—540 s Values are the average of at least three experiments error limits are standard deviations.

Figure 8. Adsorption of fibrinogen on glass in the presence of ghost cells. Conditions buffer—PBS, pH 7.35 and fibrinogen concentration—1.0 mglmL in free volume. Values are the average of three experiments. Key 0> ghosts at 15% HCT , ghosts at 45% HCT and —, level in absence of ghosts.

Figure 2. Adsorption isotherm of fibrinogen on glass in low concentration regimd.

Fig. 23. Brash and ten Hove s results on the adsorption of three plasma proteins from diluted plasma as a function of total plasma concentration. Up adsorption on glass showing a maximum adsorption of fibrinogen at about 1% plasma Down adsorption on polyethylene plasma was diluted with isotonic Tris, pH 7.35. Adsorption time was 5 minutes (reprinted from Ref.1031)...

In recent, unpublished experiments, the protein that platelets were suspended in appeared to determine to which film of protein they would adhere. For example, platelets suspended in albumin may adhere less to fibrinogen than to gamma-globulin films on glass or anodized tantalum. 

Figure 1 Adhesion of 5iCr-labelled platelets on a fibrinogen-coated glass tube at a wall shear rate of 80 s - Curves starting from the uppermost are for 0.5, 1.5, 2.5, 3.5, 5.0, 7.0 and 9.0 cm from the tube s inlet. (Reproduced with permission from Ref. 6. Copyright 1981 ASAIO Publications.1...

Figure 3. Platelet accumulation on the first 1 cm of fibrinogen-coated glass tubes versus time with and without thrombin prestimulation. (Reproduced with permission from Ref. 11. Copyright 1986 Pergamon Journals, Inc.)...

Table I. Overall Accounting for Platelets Arriving on Fibrinogen-coated Glass...

TABLE II. Overall Accounting for Platelets Arriving on Albumin-coated and Fibrinogen-coated Glass at 1.0 ml/min (80 s ) Basis 100 Platelets Contacting the Surface... 

Static Adsorption of Plasma Proteins on Glass. Initial studies of the interaction of proteins with artificial surfaces concerned the highly simplified situation of static adsorption on glass from solutions of purified radiolabeled human plasma proteins. Albumin was chosen as a major plasma protein known for its non thrombogenic properties (5>6). Fibrinogen and fibronectin, on the contrary, are major proteins of plasma which enhance platelet and cellular adhesion (4.5.7.23-25). 

Table II. Accumulation of Washed Human Platelets Labeled with Indium on Glass Capillary Surfaces Precoated with Purified Human Albumin, Human Fibrinogen or Bovine Collagen...

Table IV. Platelet Accumulation from Heparin Anticoagulated Whole Blood on Glass Capillary Surfaces Precoated v/ith Purified Human Albumin, Hnman Fibrinogen or Bovine Collagen. Quantitaticr of Platelet Deposition by Badioimmuroassay with Iodine Labeled Monoclonal Antibody 6C9 against Human Platelet Glycoprotein Complex Ilb-IIIa...

An alternative explanation of fibrinogen degradation on glass is that adsorption renders the molecule more susceptible to hydrolytic attack (either enyzme-related or otherwise). In this regard, it is worth noting that the o-chains, which are known to be hydrophilic and to extend as random coils into the aqueous phase ( ), are the most extensively degraded in all eluted fractions. 

Figure 7. Adsorption on glass from various mixtures of albumin and fibrinogen. Reproduced with permission from Ref. 7-Copyright 1976, Pergamon Press, Inc.

This Table (25) gives the fibrinogen albumin mole ratio in the layer adsorbed from solutions having a mole ratio of 0.005t close to the ratio found in normal human plasma. The surface mole ratios range from 0.05 to 0.5. reflecting a surface enrichment factor between 10 and 100. For the same solution ratio, the surface enrichment on glass is about 450. 

Figure 8. Adsorption on glass from the ternary system fibrinogen-albumin-I G, concentrations 0.09 1.20 and 0.36 mg ml respectively Buffer 0.05 M Tris, pH 7.35.

The transient adsorption of fibrinogen from diluted blood plasma on glass surfaces is shown in Figures 15.21a and b. The (higher molar mass) compounds that displace fibrinogen from the surface occur in relatively low concentrations in... 

FIGURE 15.21 Adsorption of fibrinogen from diluted blood plasma on glass, displayed (a) as a function of time for varying dilutions, and (b) as a function of dilution at various time intervals. (Data taken from Vroman, L. and Adams, A.L., J. Colloid Interface Sci., Ill, 391, 1986.) The transient adsorption of fibrinogen from blood plasma is known as the Vroman effect . 

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