Effects and Mechanisms of Drug-Loaded Ulinastatin Nanoparticles on Inflammatory Response in Sepsis
Authors: Xiong Shenming , Guo Weidong , Ren Zhangpeng , Fu Yun 
Published: June 2021

This work was aimed to explore the effects of ulinastatin nanoparticles on the related inflammatory indicators of cardiac microvascular endothelial cells (CMVECs) induced by lipopolysaccharides (LPS) and its mechanism of action on the inflammatory response to sepsis. First, the solvent
diffusion method was applied to prepare drug-loaded ulinastatin nanoparticles, so as to measure the particle size, encapsulation efficiency, and drugloading rate of the ulinastatin nanoparticles. Then, CMVECs were cultivated and damaged by LPS, which were divided into group I (without any
treatment), group II (injected with 5,000 μ/mL ulinastatin), group III (with 5,000 μ/mL ulinastatin nanoparticles), IV group (with 10,000 μ/mL ulinastatin nanoparticles), and V group (with 20,000 μ/mL ulinastatin nanoparticles). The changes of cell inflammatory
factors in each group before and after intervention were detected, including tumor necrosis factor-α (TNF-α), interleukin-β (IL-β), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), microtubule-associated protein 1 light chain
3-1 (LC3-1), and autophagy-related gene 5 (Atg5). Finally, 30 healthy male Wistar rats were selected to construct the sepsis rat model by cecal ligation and puncture (CLP), which were divided into a control group (group A), a sham operation group (group B), a ulinastatin group (group C), a
low-dose ulinastatin nanoparticle group (group D), a mediumdose ulinastatin nanoparticle group (group E), and a high-dose ulinastatin nanoparticle group (group F). The expression levels of TNF-α, cardiac troponin I (cTnI), endothelin-1 (ET-1), and p38 mitogen-activated protein
kinase (p38 MAPK) and phosphorylated-p38 MARK (p-p38 MARK) in serums of the rats were detected. The results demonstrated that the encapsulation rate of ulinastatin nanoparticles was 68.28 ± 2.28 (%), the drugloading rate was 3.26 ± 0.18 (%), and the particle size was 351.25 ±
125.63 (nm), which was higher than the blank nanoparticles of 212.34 ± 98.26 (nm), P 0.05. After the intervention with ulinastatin, the levels of inflammatory factors IL-β, IL-1, IL-6, IL-8, TNF-α, LC3-1, and Atg5 in each group showed a marked downward
trend from time T0 to T2, and there was a statistically great difference among the 6 groups at time T2 (P 0.05). The levels of cTnI, TNF-α, and ET-1 and the protein contents of p-p38 MAPK and p38 MAPK in the serums of group C, D, E, and F were sharply lower than those of
group A (P 0.05); the levels of cTnI, TNF-α, and ET-1 and the protein contents of p-p38 MAPK and p38 MAPK in the serums of group D, E, and F were considerably lower than those of group C (P 0.05); and the levels of cTnI, TNF-α, and ET-1 and the protein
contents of p-p38 MAPK and p38 MAPK in group E and F were lower extremely than those of group D (P 0.05). It indicated that the ulinastatin nanoparticles could slow down the inflammatory response of CMVECs induced by LPS to inhibit their inflammatory response of septic rats and reduce
the expression of myocardial protein.