Evaluation of the effects of adipose-derived mesenchymal stem cells on intraperitoneal adhesions

Therapeutic effect of adipose-derived mesenchymal stem cells in a porcine model of abdominal sepsis

BACKGROUND

The term sepsis refers to a complex and heterogeneous syndrome. Although great progress has been made in improving the diagnosis and treatment of this condition, it continues to have a huge impact on morbidity and mortality worldwide. Mesenchymal stem cells are a population of multipotent cells that have immunomodulatory properties, anti-apoptotic effects, and antimicrobial activity. We studied these capacities in a porcine model of peritoneal sepsis.

METHODS

We infused human adipose-derived mesenchymal stem cells (ADSCs) into a porcine model of peritoneal sepsis. Twenty piglets were treated with antibiotics alone (control group) or antibiotics plus peritoneal infusion of ADSCs at a concentration of 2 × 106 cells/kg or 4 × 106 cells/kg (low- and high-dose experimental groups, respectively). The animals were evaluated at different time points to determine their clinical status, biochemical and hematologic parameters, presence of inflammatory cytokines and chemokines in blood and peritoneal fluid, and finally by histologic analysis of the organs of the peritoneal cavity.

RESULTS

One day after sepsis induction, all animals presented peritonitis with bacterial infection as well as elevated C-reactive protein, haptoglobin, IL-1Ra, IL-6, and IL-1b. Xenogeneic ADSC infusion did not elicit an immune response, and peritoneal administration of the treatment was safe and feasible. One day after infusion, the two experimental groups showed a superior physical condition (e.g., mobility, feeding) and a significant increase of IL-10 and TGF-β in blood and a decrease of IL-1Ra, IL-1b, and IL-6. After 7 days, all animals treated with ADSCs had better results concerning blood biomarkers, and histopathological analysis revealed a lower degree of inflammatory cell infiltration of the organs of the peritoneal cavity.

CONCLUSIONS

Intraperitoneal administration of ADSCs as an adjuvant therapy for sepsis improves the outcome and diminishes the effects of peritonitis and associated organ damage by regulating the immune system and reducing intra-abdominal adhesions in a clinically relevant porcine model of abdominal sepsis.

Regenerative Medicine Therapies for Prevention of Abdominal Adhesions: A Scoping Review

INTRODUCTION

Globally, abdominal adhesions constitute a significant burden of morbidity and mortality. They represent the commonest complication of abdominal operations with a lifelong risk of multiple pathologies, including adhesive small bowel obstruction, female infertility, and chronic pain. Adhesions represent a problem of the entire abdomen, forming at the time of injury and progressing through multiple complex pathways. Clinically available preventative strategies are limited to barrier technologies. Significant knowledge gaps persist in the characterization and mitigation of the involved molecular pathways underlying adhesion formation. Thus, the objectives of this scoping review are to describe the known molecular pathophysiology implicated in abdominal adhesion formation and summarize novel preclinical regenerative medicine preventative strategies for potential future clinical investigation.

METHODS

A literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews Extension for Scoping Reviews. Included peer-reviewed publications were published within the last 5 y and contained in vivo preclinical experimental studies of postoperative adhesions with the assessment of underlying mechanisms of adhesion formation and successful therapy for adhesion prevention. Studies not involving regenerative medicine strategies were excluded. Data were qualitatively synthesized.

RESULTS

A total of 1762 articles were identified. Of these, 1001 records were excluded by the described screening criteria. Sixty-eight full-text articles were evaluated for eligibility, and 11 studies were included for review.

CONCLUSIONS

Novel and reliable preventative strategies are urgently needed. Recent experimental data propose novel regenerative medicine targets for adhesion prevention.

Peritoneal adhesions: Occurrence, prevention and experimental models

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.