The present invention provides methods for making, delivering and using formulations that combine a therapeutically active agent(s) (such as for example a Rho antagonist(s)) and a flowable carrier component capable of forming a therapeutically acceptable matrix in vivo (such as for example tissue adhesives), to injured nerves to promote repair and regeneration and regrowth of injured (mammalian) neuronal cells, e.g. for facilitating axon growth at a desired lesion site. Preferred active agents are known Rho antagonists such as for example C3, chimeric C3 proteins, etc. or substances selected from among known trans-4-amino(alkyl)-1-pyridylcarbamoylcyclohexane compounds or Rho kinase inhibitors. The system for example may deliver an antagonist(s) in a tissue adhesive such as, for example, a fibrin glue or a collagen gel to create a delivery matrix in situ. A kit and methods of stimulating neuronal regeneration are also included.