To institutionalize someone is to send them to a place where they can be taken care of. Institutionalize also means that something is part of the system. If men are paid more than women, then gender bias has been institutionalized.
The verb institutionalize is usually used to talk about committing people to hospitals, nursing homes, or other facilities where they will live and be taken care of in some way. There's another meaning of the word that means "to establish as a regular way of doing things." In this case, a teacher might institutionalize the tradition of ordering pizza for the class once a month; in other words, pizza parties would become a permanent, official part of the school year.