TPP1 and late infantile neuronal ceroid lipofuscinosis: TPPI-plasmid DNA transfected peritoneal macrophages or sonication and permeabilization of EVs with saponin to load TPPI In vitro CLN2-/- skin fibroblasts In vivo Intraperitoneal EV administration in late-infantile neuronal ceroid lipofuscinosis (LINCL) mice