O-102 Polymeric scaffold loaded with CD133+ BMDSCs for endometrial regeneration in Asherman’s syndrome
Authors: Venkatesan N , Fernandez Garcia E , Santamaria Costa X , Simon Valles C 
Published: August 2021

Abstract

Study question
Can CD133+ bone marrow-derived stem cells (BMDSCs) loaded in polyethylene glycol diacrylate (PEGda) and gelatin divide and decidualize?

Summary answer
Biocompatible porous PEGda and gelatin scaffold provides a three-dimensional environment for CD133+ cells to attach, divide, and decidualize in vitro.

What is known already
Intrauterine adhesions (IUA) develop due to acquired damages in the endometrium resulting in partial to complete endometrial dysfunction in the Asherman syndrome. Previous works from our group have demonstrated the engraftment of CD133+ BMDSCs and its paracrine effect on endometrial proliferation, improved endometrial thickness and clinical outcome in murine and human models of Asherman syndrome (AS).

Study design, size, duration
Human CD133+ BMDSCs were obtained from refractory AS patients undergoing autologous cell therapy. Two different polymers PEGda and gelatin were analysed for their ability to form porous scaffold. CD133+ BMDSCs cell adhesion and division was analysed up to
14 days, and its differentiation upon 8-Br-cAMP was evaluated in vitro on day 5. In vivo biocompatibility was evaluated until week 5.

Participants/materials, setting, methods
Porous PEGda and gelatin scaffolds were synthesized by cryogelation. Porosity, interconnectivity, and its distribution were characterized by scanning electron microscopy (SEM) and micro-computed tomography. Cell adhesion, growth, and morphology were analysed by SEM and fluorescence microscopy while decidualization of the adhered cells were analysed by prolactin (PRL) and IGFBP1 secretion by ELISA and the mRNA expression levels by qPCR. Biocompatibility and degradation of the scaffolds were analysed by sub-cutaneous implantation in Sprague -Dawley rats.

Main results and the role of chance
The average pore size was higher in the case of gelatin (100 – 250 µm) compared to PEGda which had compact structure with through pores (25 – 150 µm) and thick walls. Cross-sectional analysis revealed, well interconnected pores in both polymers. There was no significant difference between the two polymers with respect to cell adhesion, and viability (&gt; 80% in both the cases). There was a significant increase in the expression of mRNA levels of IGFBP1 with a fold change of 3 ± 2.25 (PEGda), and 10 ± 1.3 (gelatin) whereas for PRL it was 0.08 ± 0.82 (PEGda), and 0.39 ± 1.7 (gelatin) when treated with cAMP. Secretion of IGFBP1 (7.4 ± 4.5 pg/ml for PEGda and 8.5 ± 4 pg/ml for gelatin) and PRL (4.7 ± 1.8 pg/ml for PEGda and 5.6 ± 1.2 pg/ml for gelatin) also increased with the addition of cAMP. In vivo, PEGda degraded at a faster rate (∼ 3 weeks) compared to gelatin (&gt; 5 weeks) with no inflammatory reaction. Subcutaneous polymer degradation study was carried out to determine its degradation rate, its effect on inducing fibrosis, and to test its use as subcutaneous implant to aid in the regeneration of endometrium.

Limitations, reasons for caution
This is an in vitro study.

Wider implications of the findings
CD133+ BMDSCs loaded inflatable PEGda and gelatin scaffold could be a potential alternative to deliver the cells locally for the repair of endometrial damage provoked by the iatrogenic destruction of the endometrial niche.

Trial registration number
Not applicable