SBF

Protocol for Preparing Simulated Body Fluid (SBF)

 

which has ion concentrations nearly equal to those of human blood plasma and is buffered at pH 7.40 with 50 mM trishydroxymethylaminomethane and 45 mM hydrochloric acid at 36.5°C.

Department of Material Chemistry,

Graduate School of Engineering, Kyoto University

 

Wash all the bottles and wares with 1N-HCl solution, neutral detergent, and ion -exchanged and distilled water, and then dry them. Put 500 ml of ion-exchanged and distilled water into one liter polyethylene bottle, and cover the bottle with a watch glass. Stir the water in the bottle with a magnetic stirrer, and dissolve the reagents one by one in the order as given in Table 1 (One after the former reagent was completely dissolved). Adjust the temperature of the solution in the bottle at 36.5℃ with a water bath, and adjust pH of the solution at pH 7.40 by stirring the solution and titrating 1N-HCl solution (When the pH electrode is removed from the solution, add the water used for washing the electrode to the solution). Transfer the solution from the polyethylene bottle to a volumetric glass flask. Add the water used for washing the polyethylene bottle to thew solution in the flask. Adjust the total volume of the solution to one liter by adding ion-exchanged and distilled water and shaking the flask at 20℃. Transfer the solution from the flask to a polyethylene or polystyrene bottle, and store the bottle in a refrigerator at 5-10℃ (If some substance is precipitated in the solution during the storage, do not use this solution as SBF and its container again).

Table 1. Ion concentrations (mM) of SBF and juman blood plasma

 

Ion

Simulate Body Fluid

Blood plasma

Na+

142.0

142.0

K+

5.0

5.0

Mg2+

1.5

1.5

Ca2+

2.5

2.5

Cl-

148.8

103.0

HCO3-

4.2

27.0

HPO42-

1.0

1.0

SO42-

0.5

0.5

Table2. Regents for preparing SBF (pH7.40, 1L)

Order

Reagent

Amount

1

NaCl

7.996 g

2

NaHCO3

0.350 g

3

KCl

0.224 g

4

K2HPO4?3H2O

0.228 g

5

MgCl2?6H2O

0.305 g

6

1M-HCl

40 mL

(About 90 % of total amount of HCl to be added)

7

CaCl2

0.278 g

8

Na2SO4

0.071 g

9

(CH2OH)3CNH2

6.057 g

 

 

Figure 1. Preparation of SBF.

 

 

T. Kokubo, H. Kushitani, S. Sakka, T. Kitsugi and T. Yamamuro, "Solutions able to reproduce in vivo surface-structure changes in bioactive glass-ceramic A-W", J. Biomed. Mater. Res., 24, 721-734 (1990).