H. Aranda-espinoza et al., Electrostatic repulsion of positively charged vesicles and negatively charged objects, SCIENCE, 285(5426), 1999, pp. 394-397
A positively charged, mixed bilayer vesicle in the presence of negatively c
harged surfaces (for example, colloidal particles) can spontaneously partit
ion into an adhesion zone of definite area and another zone that repels add
itional negative objects, Although the membrane itself has nonnegative char
ge in the repulsive zone, negative counterions on the interior of the vesic
le spontaneously aggregate there and present a net negative charge to the e
xterior. Beyond the fundamental result that oppositely charged objects can
repel, this mechanism helps to explain recent experiments on surfactant ves
icles.