Abstract: According to one embodiment, a person's own RBCs can be recruited as secondary bioscavenger carriers in vivo using a nanopolymer-BChE complex, with an affinity ligand (antibody or peptide) for selective targeting to the RBCs and a cell-penetrating peptide for uptake into the RBCs. A general approach according to an embodiment involves parenteral administration of the nanodevice to gain access to the systemic circulation, which then seeks out and attaches to the person's RBCs, followed by transport into the RBCs (to minimize clearance from the circulation), leading to long-term circulation of the bioscavenger enzymes and thus protection against intoxication.