A method is described herein for the treatment of intracranial aneurysms. The method comprises inserting into an aneurysm an embolism coil coated with a polymeric coating comprising a genipin, such as genipin or a derivative thereof, thereby increasing the stability of clots within the aneurysm. According to one example, the coating is a poly(L-lactide-co-glycolide) (PLGA) is used to release genipin to crosslink fibrin clots thereby creating more stable occlusions. Increased clotting can improve segregation of the weakened portion of the blood vessel from the rest of the vasculature and reduce the risk of recurrence.