Chitosan Microparticles Intended for Anti-caries DNA Vaccine Mucosal Delivery: Synthesis, Characterization and Transfection

In order to enhance the mucosal immunity of anti-caries DNA vaccine, chitosan-DNA microparticles for musocal vaccination were prepared by a coacervation method. The physicochemical structure of microparticles was investigated by a scanning electron microscope (SEM) and a cofocal laser scanning microscope (CLSM). For in-vitro studies, Hela cell was transfected by chitosan-DNA microparticles.The expression of proteins was measured by the immunohistochemical methods, and the cytotocity of chitosan in Hela cell line was determined by the MTT assay. The experimental results show that the microparticles are about 2-6 μm in size and spherical in shape. The encapsulation efficiency is 99%, and the DNA is almost captured in the micropraticles. Plasmid loaded into chitosan microparticles is distributed throughout these particles. The number of positive staining cells of chitosan-pGJA-P transfected cell is more than that of naked plasmid transfect cells, but less than that of Lipofect-DNA complex group. Chitosan was found to be less cytotoxic compared with lipofectin (p<0.01).

Immunogenicity and Prediction of Epitopic Region of Antigen Ag Ⅰ/Ⅱ and Glucosyltransferase from Streptococcus mutans

The levels of Streptococcus（S.） mutans infections in saliva were evaluated and a comparison for specific antibody levels among children with different levels of S. mutans infection was made. The promising epitopic regions of antigen AgⅠ/ Ⅱ（PAc） and glucosyltransferase（GTF） for potential vaccine targets related to S. mutans adherence were screened. A total of 94 children aged 3–4 years were randomly selected, including 53 caries-negative and 41 caries-positive children. The values of S. mutans and those of salivary total secretory immunoglobulin A（s Ig A）, anti-PAc and anti-Glucan binding domain（anti-GLU） were compared to determine the correlation among them. It was found the level of s-Ig A against specific antigens did not increase with increasing severity of S. mutans infection, and the complete amino acid sequence of PAc and GTFB was analyzed using the DNAStar Protean system for developing specific anti-caries vaccines related to S. mutans adherence. A significantly positive correlation between the amount of S. mutans and children decayed, missing, and filled teeth index was observed. No significant difference was detected in specific s Ig A against PAc or GLU between any two groups. No significant correlation was found between such specific s Ig A and caries index. A total of 16 peptides from PAc as well as 13 peptides from GTFB were chosen for further investigation. S. mutans colonization contributed to early children caries as an important etiological factor. The level of s Ig A against specific antigens did not increase with increasing severity of S. mutans infection in children. The epitopes of PAc and GTF have been screened to develop the peptide-based or protein-based anti-caries vaccines.

Development of Chinese Kids Toothpaste Market

The development of kids toothpaste in Chinese market has been introduced, and the common characterisUcs of kids toothpaste in the production and sales have been analyzed. Through the analysis of the characteristics of kids oral care, the special technical requirements of kids toothpaste are elucidated. Finally, suggestions for the future development of kids toothpaste are put forward.