Electrospun Nanofiber Meshes With Endometrial MSCs Modulate Foreign Body Response by Increased Angiogenesis, Matrix Synthesis, and Anti-Inflammatory Gene Expression in Mice: Implication in Pelvic Floor.

Shayanti Mukherjee,Kallyanashis Paul,Jerome A Werkmeister,Fiona L Cousins,Caroline E Gargett,Saeedeh Darzi

doi:10.3389/fphar.2020.00353

Abstract

PurposeTransvaginal meshes for the treatment of Pelvic Organ Prolapse (POP) have been associated with severe adverse events and have been banned for clinical use in many countries. We recently reported the design of degradable poly L-lactic acid-co-poly ε-caprolactone nanofibrous mesh (P nanomesh) bioengineered with endometrial mesenchymal stem/stromal cells (eMSC) for POP repair. We showed that such bioengineered meshes had high tissue integration as well as immunomodulatory effects in vivo. This study aimed to determine the key molecular players enabling eMSC-based foreign body response modulation.MethodsSUSD2+ eMSC were purified from single cell suspensions obtained from endometrial biopsies from cycling women by magnetic bead sorting. Electrospun P nanomeshes with and without eMSC were implanted in a NSG mouse skin wound repair model for 1 and 6 weeks. Quantitative PCR was used to assess the expression of extracellular matrix (ECM), cell adhesion, angiogenesis and inflammation genes as log2 fold changes compared to sham controls. Histology and immunostaining were used to visualize the ECM, blood vessels, and multinucleated foreign body giant cells around implants.ResultsBioengineered P nanomesh/eMSC constructs explanted after 6 weeks showed significant increase in 35 genes associated with ECM, ECM regulation, cell adhesion angiogenesis, and immune response in comparison to P nanomesh alone. In the absence of eMSC, acute inflammatory genes were significantly elevated at 1 week. However, in the presence of eMSC, there was an increased expression of anti-inflammatory genes including Mrc1 and Arg1 by 6 weeks. There was formation of multinucleated foreign body giant cells around both implants at 6 weeks that expressed CD206, a M2 macrophage marker.ConclusionThis study reveals that eMSC modulate the foreign body response to degradable P nanomeshes in vivo by altering the expression profile of mouse genes. eMSC reduce acute inflammatory and increase ECM synthesis, angiogenesis and anti-inflammatory gene expression at 6 weeks while forming newly synthesized collagen within the nanomeshes and neo-vasculature in close proximity. From a tissue engineering perspective, this is a hallmark of a highly successful implant, suggesting significant potential as alternative surgical constructs for the treatment of POP.

Highlights

Pelvic Organ Prolapse (POP) is a debilitating urogynecological pelvic floor disorder that significantly impacts the quality of lives of 50% of parous women aged over 50 years (Nygaard et al, 2008)
At 6 weeks, there was a substantial amount of collagen inside the Nanomesh in the P+eMSC group compared to P alone
Our results show that presence of eMSC increases new collagen subunit synthesis which may be mediated by increased Tgfb1 and Tgfb3 gene expression within implanted P nanomesh, may foster tissue integration via the expression of extracellular matrix (ECM) formation and cell adhesion genes by 6 weeks but not as early as 1 week in vivo

Summary

Introduction

Pelvic Organ Prolapse (POP) is a debilitating urogynecological pelvic floor disorder that significantly impacts the quality of lives of 50% of parous women aged over 50 years (Nygaard et al, 2008). A growing body of evidence shows implant failures and have established that prolonged inflammation and undesirable foreign body response (FBR) are associated with complications in patients (Deprest et al, 2009; Claerhout et al, 2010; Brown et al, 2015; Jallah et al, 2016; Nolfi et al, 2016; Tennyson et al, 2019) Such FBRs and associated adverse effects of transvaginal meshes were deemed to out-weigh PP benefits and led to the ban on transvaginal meshes in Australia, UK, and USA by regulatory authorities, with no alternative treatments on the horizon. More reliable treatment measures that promote tissue healing and repair without piquing deleterious FBR are pivotal for the treatment of POP (Siddiqui et al, 2018)

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