Oral administration vaccine against dental caries by biodegradable polymer microparticle

Objectives: PBLG-PEG-PBLG block copolymer composed of Poly(g-benzyl L-glutamate) as the hydrophobic block and ploy(ethylene glycol) as the hydrophilic block was selected as carrier to prepare microparticle which can hold HDS and intensify vaccine immunoreaction. To investigate the colonization of rats` teeth by Streptococcus mutans and the effect of oral administration vaccine against dental caries. Methods: 28 Sprague-Dawley rats were divided into 4 groups randomly. Oral adminstration groups were: pure micropaticle only(group A),pure micropaticle mixed HDS(group B),HDS microparticle(group C) and HDS microparticle injected groups(group D).Gnotobiotic rat model was developed when challenged by S. mutans and a caries promoting diet(Diet 2000^#). The numbers of colonized S. mutans were counted and the presence of caries was examined by the procedure of Keyes. Results:The number of S. mutans in HDS microparticle group(group C) is 16.7±8.21x10⁴CFU/ml and carious lesions is 30.8±7.11, lower than the contrastive groups(P<0.01). Conclusions: The micropaticle vaccine could reduce the caries incidence in experimental caries rat models. The protection immunization effect against dental caries was especially significant on smooth surface of teeth.