Delivery devices with pressure control mechanisms are described herein. In some embodiments an apparatus includes a reservoir configured to contain a fluid, the reservoir having an inlet port and an outlet port. A plunger is disposed within the reservoir such that the reservoir is divided into a first portion and a second portion. The inlet port is in fluid communication with the first portion of the reservoir, and the outlet port is in fluid communication with the second portion of the reservoir. A pressure control device configured to control a pressure of the fluid within the first portion of the reservoir is in fluid communication with the first portion of the reservoir.