Objective To increase the antigen presentation and immune response of liposomal vaccines through IgM functionalization strategy. Methods Folic acid-modified liposomes loaded with ovalbumin （FA-sLip/OVA） were prepared. The binding ability of liposomal vaccines with IgM was investigated by ELISA method. The IgM in the protein corona was analyzed by SDS-PAGE and Western Blot. Mice were immunized by intravenous injection to investigate the spleen B cell targeting and immune activation of vaccines. Results The average particle size of FA-sLip/OVA was about 117 nm. The specific binding between FA-sLip and IgM was verified by ELISA method. Folic acid-modified liposomal vaccines could absorb IgM in mouse serum and form protein coronas on the surface. Intravenous immunization could stimulate mice to produce long-lasting, high-level antibody titers. Conclusion Natural IgM-enabled folic acid-modified liposomal vaccines were successfully prepared which could effectively induce immune response and provide a new idea for the research of nano-vaccines.

OBJECTIVE To study the quality grade stand ard of the premature Forsythia suspensa . METHODS A total of 138 batches of premature F. suspensa were collected from the main producing areas of F. suspensa in China. According to 2020 edition of Chinese Pharmacopoeia ，the contents of impurities ，moisture，ethanol-soluble extract ，volatile oil ，forsythin and forsythoside A in the premature F. suspense were determined ，and the qualified samples were screened. AHP-PCA mixed weighting method was used to give comprehensive weight to the indicators （except for the limit of impurity ）. The comprehensive score of the samples was calculated. The suggestions on the quality grade division of premature F. suspensa were put forward according to cluster analysis of K-mean value. RESULTS & CONCLUSIONS The contents of impurities ，moisture，ethanol-soluble extract ，volatile oil ，forsythin and forsythoside A in the premature F. suspense were 0-7.80％，1.60％-8.18％，13.13％-61.60％，0.21％-3.47％，0.02％-2.15％ and 0.79％-14.04％，respectively；average contents of them were 1.24％，4.97％，34.88％，2.01％，0.42％，6.86％，respectively. Totally 47 batches of 138 batches were qualified in all indexes. It is suggested that the quality grade of the premature F. suspense can be divided into three grades ：in first grade of F. suspense ，the contents of volatile oil ，forsythin，forsythoside A ， ethanol-soluble extract and moisture were ≥2.40％，≥0.59％，≥8.34％，≥38.66％ and ≤4.99％，respectively；in second grade of F. suspense ，the contents of above indicators were ≥2.26％，≥0.41％，≥7.47％，≥32.58％ and ≤5.33％，respectively；in third grade of F. suspense ，the contents of above indicators were ≥2.15％，≥0.32％，≥4.60％，≥31.52％ and≤7.23％，respectively.