Environmental Engineering Reference
In-Depth Information
Fig. 15.4 Nanoparticle and method related parameters that affect the protein separation patterns
when separated by gel electrophoresis
running electrolyte did not contain any SDS. The separation of the silver
nanoparticles was improved upon the addition of SDS (20 mM) to the running
electrolyte. Peak that migrated more quickly (10.5 min) were of the smaller
diameter silver nanoparticles (17.0 nm); the more slowly eluting peak (12.2 min)
corresponded to the larger diameter silver nanoparticles (49.7 nm).
Particle size of nanoparticles plays a major role in adsorption of the plasma
protein corona around the nanoparticle. Molecules with molecular weight less than
5,000, or even higher for dense polymers like dendrimers, are removed from the
body via the renal system. For particles with hydrodynamic radii of over 200 nm
typically exhibit a more rapid rate of clearance than smaller particles. The biolog-
ical responses to nanoparticles tend to scale with surface area rather than mass. As
things become smaller, their surface areas shrink much more slowly than their
volumes, causing nanoscale materials to have far greater surface-to-volume ratios
than larger particles. A larger surface-to-volume ratio also implies more proteins
will bind nanoparticle (relative to its mass) than a particle of larger size [
52
]
(Fig.
15.4
).
The effect of pore volume and size on the protein adsorption pattern using three
ceramic materials viz. hydroxyapatite, zirconia and alumina was studied [
53
]. The
pore volume study showed that particles of hydroxyapatite, zirconia and alumina
were porous with pore volumes ranging from 0.29 cm
3
/g up to 1.14 cm
3
/g. The size
of the pores (i.e. the pore diameters) varied somewhat among the three materials.
Zirconia was found to have the smallest pores with maximum diameters of 0.2 mm.
Hydroxyapatite and alumina had pores with up to 10 mm in diameter. The protein
binding capacity study revealed that the maximum amount of plasma proteins
adsorbed on the materials, after rinsing were 0.42 mg/m
2
on hydroxyapatite,
0.22 mg/m
2
on zirconia and 0.20 mg/m
2
on alumina. The low binding capacity of
the materials was attributed to the fact that the material being porous in nature, the
internal surface was not available for protein adsorption. The pore size distribution
study revealed that the surfaces were available from a theoretical point of view,
