Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/26/2005
Publication Date: 2/27/2006
Citation: Christie, R.J., Findley, D.J., Dunfee, M., Hansen, R., Olsen, S.C., Grainger, D.W. 2006. Photopolymerized hydrogel carriers for live vaccine ballistic delivery. Vaccine. 24(9):1462-9. Interpretive Summary: Brucella abortus is a disease that causes abortion and associated economic losses in infected cattle herds. The infection of bison with Brucella abortus in Yellowstone National Park pose a risk to the completion of the Brucellosis Eradication Program for cattle. For vaccination of bison within Yellowstone National Park, a remote vaccination method that doesn't require capture of bison is needed. In this study, we evaluated new cross-linked polymers as a vehicle for preparing ballistic bullets for vaccinating bison. This polymer does not adversely influence vaccine viability but does enhance release of vaccine after delivery to bison. Our data suggest that the new polymer will be better than the previous method of ballistic bullet preparation. It is anticipated that this polymer will facilitate development of a remote vaccination system for use on free-ranging bison in Yellowstone National Park.
Technical Abstract: Photopolymerized poly(ethylene glycol) (PEG) crosslinked hydrogels were assessed for their ability to serve as a payload vehicle to deliver a viable bacterial vaccine (Brucella abortus strain RB51) vaccine to bison in Yellowstone National Park ballistically using thermoplastic degradable biobullets. PEG modified with degradable glycolide or lactide oligomers capped with photopolymerizable methacrylate groups served to crosslink the hydrogel vaccine carrier inside commercial hydroxypropylcellulose biobullets. Release of 1-micron diameter model fluorescent particles from hydrogels follwoed known degradation trends for glycolide- and lactide-modified PEG hydrogels. All particles were released from PEG-co-glycolide hydrogels after approximately 10 days and PEG-co-lactide hydrogels after approximately 45 days following gel degradation. Minimal particle release was observed from pure PEG dimethacrylate hydrogels over 40 days. P. Aeruginosa (strain PA01) and RB51 live vaccines exhibit excellent viability following exposure to photopolymerization encapsulation within these gel matrices. Hydrogels photpolymerized into the payload chamber of biobullets exhibit similar ballistic properties to commercially available biobullets, and penetrate and remain intact when delivered intramuscularly into live elk for release of their gel payload in the host.