Biomedical Engineering Reference
In-Depth Information
A
A
A
Physical
adsorption
A
A
A
Physical
adsorption +
crosslinking
Cationic
groups
A
A
A
Ionic
adsorption
Lipid
groups
A
Hydrophobic
interaction
adsorption
Dye
molecules
A
Dye affinity
adsorption
Reactive
groups
A
A
Covalent
binding + or
−
"arm" or
"leash"
A
Fig. 3.2.16-4 Schematic of various ways that albumin may be immobilized on a surface. Albumin is often used as a ''passivating''
protein, to minimize adsorption of other proteins to a surface.
Table 3.2.16-7 Biomolecule immobilization methods
Method
Physical and electrostatic
adsorption
Cross-linking
(after physical adsorption)
Entrapment
Covalent
binding
Ease
High
Moderate
Moderate to
low
Low
Loading level possible
Low
(unless high S/V)
Low
(unless high S/V)
High
(depends on
S/V and site density)
Low to none
a
Leakage (loss)
Relatively high
(sens. to
6
pH salts)
Relatively low
Low to none
Cost:
Low
Low to moderate
Moderate
High
a
Except for drug delivery systems.
