Bacterial outer membrane vesicles (OMVs) are readily amenable to engineering but naturally lack active targeting ability. In this study, the HLYVSPW peptide was displayed on the surface of OMVs using cytolysin A (ClyA) to construct Toll-like receptor 2 (TLR2)-targeted engineered OMVs (HLYV-OMVs), and their in vitro targeted uptake by triple-negative breast cancer cells was evaluated. HLYV-OMVs were prepared by ultracentrifugation and characterized by transmission electron microscopy, dynamic light scattering, zeta potential analysis, and proteinase K protection assays. TLR2-high-expressing MDA-MB-231 cells, TLR2-knockdown MDA-MB-231 cells (231-siTLR2), and MCF-10A cells were used to evaluate cell viability, cellular uptake, and batch-to-batch reproducibility. HLYV-OMVs exhibited a typical bilayer vesicular morphology with particle sizes of approximately 56–64 nm, and the HLYVSPW peptide was successfully displayed on the vesicle surface. Within the tested dose and exposure ranges, HLYV-OMVs did not cause an obvious decrease in cell viability. Their uptake by MDA-MB-231 cells was higher than that by TLR2-knockdown cells and MCF-10A cells and increased in a dose-related manner. Particle size and cellular uptake results showed a certain degree of reproducibility across batches. These findings indicate that HLYV-OMVs exhibit a TLR2 expression-associated uptake advantage in vitro and may provide an experimental basis for developing targeted delivery platforms for triple-negative breast cancer.
Objective To preliminarily understand the equipment configuration and information system function improvement of the microbiology laboratory for etiological submission before antibiotic treatment in Chinese medical institutions, and provide a scientific basis for further targeted action work on the rate of etiological submission before antibiotic treatment. Methods A network questionnaire was released in “Sentinel Hospital Information Reporting System of National Hospital Infection Management Professional Quality Control Center” between March 1 and June 21, 2022. The second-level and above hospitals were investigated. Results A total of 783 hospitals were included, of which 765 (97.7%) hospitals had been equipped with microbiology laboratory equipment to varying degrees, and the allocation rate of tertiary hospitals was higher than that of secondary hospitals (P<0.05). The top three items of common pathogenic test were aerobic (98.3%), bacterial smear (97.6%) and fungal smear (95.1%), and the last three items were streptococcus pneumoniae urine antigen (20.4%), silver hexamine staining (19.0%) and gene sequencing (8.9%). The comparison of relevant information system and function improvement among hospitals of different levels showed that tertiary hospitals were superior to secondary hospitals (P<0.05). In different regions, except for the allocation rate of nosocomial infection information monitoring system and rational drug use monitoring system (P>0.05), other relevant systems and functional improvement of hospitals in eastern, central and western regions, the differences were statistically significant (P<0.05). The number of hospitals that could obtain the indicators of “etiological submission rate of inpatients before antibiotic treatment”“etiological submission rate related to hospital infection diagnosis”“etiological submission rate before combined use of key drugs” were 698 (89.1%), 474 (60.5%) and 337 (43.0%), respectively. Among the factors affecting the implementation of special actions, 454 hospitals (58.0%) thought that the information system was not fully functional, 341 hospitals (43.6%) thought that the etiology testing project was not fully carried out, and 148 hospitals (18.9%) thought that the microbiology laboratory testing ability was insufficient. Conclusion All kinds of hospitals at all levels in China, especially specialized and secondary hospitals, need to further improve the configuration of equipment and information system functions in the microorganism laboratory related to aetiology inspection, strengthen the support for microbial inspection, and strengthen information management, monitoring and analysis.