Mn. Jones et al., TARGETING AND DELIVERY OF BACTERICIDE TO ADSORBED ORAL BACTERIA BY USE OF PROTEOLIPOSOMES, Biochimica et biophysica acta, 1147(2), 1993, pp. 251-261
Proteoliposomes having surface-bound succinylated concanavalin A (s-co
nA) have been prepared from a range of phospholipid mixtures by sonica
tion (SUV) and reverse phase evaporation (REV) covering a range of siz
e (weight-average diameter (d(w)BAR)) from approx. 35 to 310 nm and we
ight-average number of protein molecules per liposomes (P(w)BAR) from
approx. 50 to 3000. The targeting of the proteoliposomes to adsorbed b
iofilms of the bacteria Streptococcus sanguis and Streptococcus mutans
has been assessed from the extent of inhibition of an enzyme-linked i
mmunosorbent assay (ELISA) for bacterial cell surface antigens. The su
rface-bound lectin enhances targeting relative to 'naked' liposomes of
comparable concentration by factors of 2-50 depending on the liposoma
l lipid composition and P(w)BAR. The effect of the bactericide Triclos
an' on the thermal properties and permeability characteristics of lipo
somes has been studied. At and above a molar ratio of Triclosan(R) to
lipid of 0.6, Triclosan(R) eliminates the gel to liquid-crystalline ph
ase transition in dipalmitoylphosphatidylcholine (DPPC) containing lip
osomes and increases the bilayer permeability of both liposomes and pr
oteoliposomes to D-glucose. The proteoliposomes have been used to deli
ver Triclosan(R) to S. sanguis biofilms and the inhibition of growth o
f the bacteria after treatment with liposomally delivered Triclosan' h
as been determined using a microtitre plate re-growth assay and compar
ed with growth inhibition by 'free' Triclosan(R). It is shown that for
short exposure times (1 to 2 min) proteoliposomally delivered Triclos
an' is a more effective growth inhibitor than free Triclosan(R). The r
esults are discussed in terms of the targeting, retention and subseque
nt release of Triclosan' into the bacterial biofilms.