Amniotic derived stem cells biocompatibility on randomly oriented electrospun poly(lactide-co-glycolide) (PLGA), poly(ɛ-caprolactone) (PCL), poly(lactic acid) (PLA) bioscaffolds

Amniotic derived stem cells (ASCs) retain great potential in cell-based regenerative medicine for their plasticity, non-tumorigenic, immunotolerance and anti-inflammatory properties. Their performance in regenerative medicine would be increased by creating ASCs engineered electrospun scaffolds in order to form a three-dimensional architecture, which resembles the natural extracellular matrix structure in human body allowing tissue regeneration and preserving its mechanical and structural properties. Thus, in this study ovine amniotic epithelial stem cells (oAECs), already proofed to be suitable for musculo-skeletal regenerative medicine, were tested for their biocompatibility in randomly oriented microfiber PLGA, PCL and PLA scaffolds, biopolymers routinely used as medical devices. In order to obtain a suitable microenvironment for cell attachment, spatial organization and proliferation, porous scaffolds were firstly fabricated using the electrospinning process. Ovine AECs, after scaffolds sterilization, were seeded and cultured for 48h. Then, oAECs biocompatibility analysis was performed on sterilized cell engineered scaffolds investigating engraftment, cell survival, spatial organization, proliferation index (PI), and DNA quantification. SEM analysis of seeded scaffolds showed oAECs engraftment in all biopolymers, in fact, after 48h incubation ultrastructural examination showed that seeded cells adhered to scaffolds microfibers covering the pores. Immunofluorescence confirmed a good cell integration and survival, although the type of biomaterial influenced their spatial distribution. In detail, oAECs seeded on all analysed scaffolds spread within the whole surface and around the microfibers especially in PLGA, which showed the best result in term of spatial distribution and organization efficiency. Cell proliferation quantification was assessed confirming their mitotic activity on scaffolds. In particular, after 48h cell proliferation index was significantly higher in PLGA compared to PCL and PLA, consistent with the morphological analysis. Moreover, DNA quantification demonstrated an increasing on cell population within all the analysed scaffolds compared to the initial quantity of DNA at the beginning of culture, especially in PLGA, confirming the proliferation data. The obtained results indicate that oAECs were able to colonize and to proliferate inside the analyzed electrospun biomaterials. Although, their biocompatibility grade and biologic activities are influenced by the scaffold chemical and ultrastructural microfibers organization. In conclusion, oAECs engineered scaffolds could represent a good synergy and safe alternative in tissue regeneration in a preclinical/clinical application, prior allo- and xeno-transplantation settings.