Objective:To analyze the risk factors for severe acute pancreatitis (SAP) complicated with infection and the effects on immune level.Methods:A total of 150 SAP patients admitted to Deyang People′s Hospital from February 2018 to April 2019 were divided into the infected group ( n=90) and the uninfected group ( n=60) according to whether SAP was complicated with infection or not; the changes of pathogenic bacteria in the infection focus, infection risk factors, blood inflammatory cytokines levels and T-lymphocyte subgroups were analyzed. Results:A total of 105 pathogenic bacteria were detected in 90 SAP patients with infection, among which 74(70.5%) were gram-negative bacteria, mainly escherichia coli, klebsiella pneumoniae and pseudomonas aeruginosa. There were 27 strains (25.7%) of gram-positive bacteria, mainly staphylococcus aureus, and 4 strains (3.81%) of fungi. Biliary causes, total parenteral nutrition time≥1 week, APACHEⅡ score≥11, surgical intervention, and respiratory mechanical ventilation were all independent factors for SAP infection (all P<0.05). At 24 hours after onset, blood IL-4(59.1±6.2)ng/L, IL-6(134.1±12.2) ng/L, IL-10(146.4±13.2)ng/L, TNF-ɑ(76.3±5.2)ng/L in infected group were all significantly higher than those in the uninfected group (all P values <0.05); at 30 days after the onset, blood IL-4(33.6±5.8)ng/L, IL-6(49.2±6.8)ng/L of the infected group, IL-10(80.7±8.8)ng/L, TNF-ɑ(28.7±5.5)ng/L in infected group were significantly lower than those in the uninfected group (all P values <0.05). At 24 hours after onset, the proportion of CD 4+ T lymphocytes in the infected group was significantly higher than that in the uninfected group [(45.3±5.5)% vs (32.3±5.2)%], and the proportion of CD 8+ T lymphocytes was significantly lower than that in the uninfected group [(20.6±4.2)% vs (29.7±4.8)%]; at 30 days after onset, the proportion of CD 4+ T lymphocytes in the infected group was significantly lower than that in the uninfected group [(21.6±3.7)% vs (40.2±2.5)%], and the proportion of CD 8+ T lymphocytes was significantly higher in the uninfected group [(48.4±4.1)% vs (32.8±4.0)%]; and all the differences were statistically significant (all P <0.05). Conclusions:The strains of concurrent infection with SAP were mainly gram-negative bacteria. Biliary causes, total parenteral nutrition time, surgical intervention and respiratory mechanical ventilation were all risk factors for concurrent infection with SAP. SAP infection may cause excessive inflammatory response and lead to immune cell damage, which should be paid attention to in clinical treatment.

Electrospray technology is a method to prepare microspheres by electrostatic force. Electrospray technology has the advantages of simple operation and mild reaction conditions. The polymer microspheres prepared by electrospray technology have uniform morphology and good monodispersity, which is a new and promising method. In this paper, the devices and principles of electrospray technology, the factors affecting the morphology and particle size of the prepared polymer microspheres by the electrospray process, and the types of polymer solutions commonly used in electrospray technology were described, and the applications of electrospray technology for drug delivery, loaded nanoparticles, cell therapy, and bioactive substance delivery were reviewed. It can be concluded that electrospray technology has a broad application prospect and potential application value.