Oral vaccines, owing to their non-invasive nature, ease of administration, and ability to elicit both mucosal and systemic immune responses, represent a pivotal direction in vaccine development. Microfold cells （M cells）, a specialized subset of immune-surveillance epithelial cells, though sparsely distributed, possess exceptional capacity for antigen uptake and transcytosis, rendering them a critical target for overcoming the bottlenecks of oral vaccine delivery. The morphological structure, antigen uptake mechanisms, and surface receptor characteristics of intestinal M cells were summarized in this paper. The multifaceted challenges currently impeding M cell-targeted oral delivery and recent advances in targeting strategies based on receptor–ligand specific recognition were analyzed. The design and application of delivery carriers tailored for M cell targeting were reviewed, which aimed to provide insights and guidance for future research and development of M cell-targeted mucosal delivery systems in the intestine.

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.