This research has investigated the use of pentablock copolymers and polyanhydride nanoparticles in combination to form a hydrogel matrix giving controlled and sustained release of model protein ovalbumin (OVA) for vaccine delivery applications. To investigate the influence of hydrogel composition on release of OVA, the weight percent of polyvinyl alcohol (PVA), form of OVA, and molecular weight of pentablock copolymer were varied. The weight percent of PVA was tested for 20% and 30%. Molecular weight of the pentablock copolymer was also varied giving a low molecular weight or high molecular weight copolymer. Lastly, OVA was incorporated into hydrogels either in a free form, encapsulated in polyanhydride nanoparticles, or a combination of the two. For all trials, the total OVA amount loaded was constant, and release curves of protein with time were observed for 4 days. Overall, these release curves confirmed gradual and controlled release of OVA. They also showed that the amount of OVA released from 20% PVA hydrogels was greater than the protein released from 30% hydrogels due to structural differences of the matrices. Lastly, the encapsulated OVA versus free OVA influenced total protein amount released and varied with % PVA and molecular weight of copolymer.