Disclosed are methods, devices and materials for the in situ formation of a nerve cap to inhibit neuroma formation following planned or traumatic nerve injury. The method includes the steps of identifying a severed end of a nerve, and positioning the severed end into a cavity defined by a form. A transformable media is introduced into the form cavity to surround the severed end. The media is permitted to undergo a transformation from a first, relatively flowable state to a second, relatively non flowable state to form a protective barrier surrounding the severed end. The media may be a hydrogel, and the transformation may produce a synthetic crosslinked hydrogel protective barrier. The media may include at least one anti-regeneration agent to inhibit nerve regrowth.