Rm. Kowalchuk et al., ZETA-POTENTIAL OF BONE FROM PARTICLE ELECTROPHORESIS - SOLUTION COMPOSITION AND KINETIC EFFECTS, Journal of biomedical materials research, 29(1), 1995, pp. 47-57
The morphology of bone may be influenced by many factors, including el
ectromechanical ones such as electric potentials, electric fields, or
zeta potentials. Stress-generated potential studies in bone and partic
le electrophoresis studies using calcium-deficient hydroxyapatite have
shown that the zeta potential depends on the composition of the steep
ing fluid and steeping time. To better quantify and understand these i
n situ potential changes in bovine cortical bone, the effects of alter
ations in calcium, phosphate, and fluoride concentrations in Neuman's
Fluid (NF), which simulates in vivo bone extracellular fluid, were inv
estigated using particle electrophoresis. The zeta potential increased
in magnitude with increased calcium concentration in NF in as little
as 17 min. Increasing phosphate concentration in NF also increased the
zeta potential magnitude. These results provide support for a structu
ral model of the bone matrix surface-bone fluid interface, which incor
porates the bone surface proper (composed of collagen, mineral, and bo
undary regions), stationary layer (in which ions, ionic complexes, and
proteins may be adsorbed), and bone extracellular fluid. These result
s, coupled with those of previous studies, indicate that the protein p
hase probably has an important role in the determination of the physio
logic zeta potential; the role of the mineral phase may also be import
ant. (C) 1995 John Wiley and Sons, Inc.