Much of the theory for BGG category O, associated to a semisimple complex Lie algebra, is controlled by a Borel subalgebra of the Lie algebra. In the context of finite dimensional algebras this is adapted by the notion of an exact Borel subalgebra. In this talk we show how to construct such a sugalgebra for every quasi-hereditary algebra up to Morita equivalence using the concept of twisted modules for A-infinity categories. This is joint work with Steffen Koenig and Sergiy Ovsienko based on the prepint arXiv:1305.2315.