Charged wormholes with non-minimally coupled scalar fields. Existence   and stability
  Static, spherically symmetric, traversable wormhole solutions with electric or magnetic charges are shown to exist in general relativity in the presence of scalar fields nonminimally coupled to gravity. These wormholes, however, turn out to be unstable under spherically symmetric perturbations. The instability is related to blowing-up of the effective gravitational constant on a certain sphere. 
K.A. Bronnikov and S. Grinyok (Moscow)