Plasma-activated solutions prevent peritoneal adhesion formation by regulating eNOS expression in mesothelial cells.

INTRODUCTION

Peritoneal adhesions cause significant morbidity due to limited therapeutic options. Current strategies are limited by inconsistent efficacy and potential side effects. Plasma-activated solutions (PAS) exhibit anti-inflammatory and healing promoting properties with good safety, their efficacy in preventing peritoneal adhesions remains further investigation.

OBJECTIVES

This study aimed to investigate the therapeutic potential of PAS in preventing peritoneal adhesion formation and to elucidate its mechanisms.

METHODS

Two murine peritoneal adhesion models ("ischemic button" and "cecum-peritoneum abrasion") were established. Human peritoneal mesothelial cell was treated with LPS or TGF-β1 to model apoptosis and mesothelial-to-mesenchymal transition (MMT) in vitro. Apoptosis was quantified via flow cytometry and western blotting; ROS levels were assessed using immunofluorescence staining. MMT markers (western blotting) and inflammatory cytokines (ELISA) were analyzed. Histological evaluation included Masson's trichrome and immunofluorescence staining.

RESULTS

PAS-2 min significantly reduced adhesion scores compared to PBS controls (ischemic button: 6.250 ± 1.389 vs. 2.5 ± 2.268; abrasion: 7.333 ± 1.033 vs. 1.633 ± 1.333, p < 0.01). In vitro, PAS treatment decreased LPS-induced apoptosis in mesothelial cells by 8.14 % (flow cytometry: 39.10 % ± 1.47 % vs. 30.96 % ± 1.73 %, p < 0.01) and suppressed MMT markers, with N-cadherin and Vimentin expression reduced by 1.46-fold (p < 0.05) and 1.62-fold (p < 0.05). PAS also attenuated oxidative stress, decreasing general ROS levels by 3-fold (p < 0.001) and mitochondrial ROS (mtROS) by 2-fold (p < 0.01). Mechanistically, reactive nitrogen species (RNS) in PAS restored eNOS expression, attenuating apoptosis and MMT in mesothelial cells.

CONCLUSION

This study demonstrates that PAS prevents peritoneal adhesions via RNS-mediated eNOS restoration, suppressing oxidative stress, apoptosis, and MMT. These findings position PAS as a novel and promising therapy for adhesion prevention, warranting clinical translation.