Hypothesis / aims of study
Vaginal childbirth inflicts substantial trauma to the pelvic floor, emerging as a pivotal risk factor for pelvic floor muscle disorders (PFDs) such as urinary incontinence (UI) and Pelvic Organ Prolapse (POP). While the damage occurs during childbirth, its
enduring impact often becomes evident later in life, marked by complications in bladder, bowel, and sexual functions. This phenomenon affects 25% of women across all age groups, underscoring the profound and lasting consequences of
maternal childbirth injury on women's pelvic health. The increasing demand for preventative treatment approaches for pelvic organ prolapse (POP) subsequent to birth injury has led to the exploration of novel biologically active scaffolds such as Aloe Vera-Alginate hydrogel (AV-ALG-Hyd) comprising xenogeneic SUSD2 +human Endometrial Mesenchymal Stem Cells (eMSC) This study addresses the urgent need for effective birth injury interventions by investigating the therapeutic potential of AV-ALG-Hyd with and without eMSC in promoting healing.
The primary aim was to construct and evaluate the efficacy of tissue engineered AV-ALG-Hyd with SUSD2+ eMSC in postpartum tissue healing. Furthermore, we aimed to assess for differences in acute inflammatory immune responses, tensile properties
of vaginal tissue explants between treatment groups, and to demonstrate optimized eMSC retention for superior immunomodulatory potential.
Study design, materials and methods
Herein, we selected primiparous ewes and simulated birth injury using a balloon catheter that is clinically used to mitigate post-partum uterine bleeding. AV-ALG-Hyd, with SUSD2+ eMSC was transplanted directly following simulated vaginal birth injury,
while control groups underwent injury without hydrogel and/or eMSC injection. Ewes transplanted with AV-ALG-Hyd without eMSCs and sham injury served as control. Explant analysis at 30 and 90-day timepoints encompassed pre-and post-operative POP-Q measurements, eMSC retention, tissue healing, immune response, and tissue tensiometry.
Results
We observed that birth injury in ewes is characterised by disruption of collagen, smooth muscle cells and elastin content within the vaginal tissue. However, an injection of AV-ALG-Hyd with SUSD2+ eMSC treatment after simulated injury could reverse these alternations. Tissue analysis revealed a trend towards increased α-Smooth Muscle Actin (αSMA) expression in the hydrogel + eMSC group at 90 days, suggesting potential benefits in smooth muscle preservation. Elastin maintenance was observed at 30 and 90-day timepoints across all groups, emphasizing the positive impact of AV-ALG-Hyd and eMSC on tissue elasticity.
eMSC based therapy promoted angiogenesis as some cells were retained up to 30 days without triggering unwanted foreign body response. Modified POP Q assessments indicated clinical benefits in the presence of eMSC + hydrogel, with a trend towards reduced descent of the Ap anatomical point. Smooth musclin actin was significantly improved in hydrogels with cells treatment at 90 days compared to leaving it entirely untreated. Further data collection is currently underway including a formal immunohistochemical study for immune markers and tensiometry experiments.
Interpretation of results
Novel cell-based tissue engineered hydrogels such as AV-ALG-Hyd with xenogenicSUSD2+ eMSC present a promising intervention for improved tissue healing subsequent to birth injury. A timely therapy has the potential to regeneration of tissues that are detrimentally affected by the impact of vaginal birth injury.