Embedding methods for poly(l-lactic acid) microfiber mesh/human mesenchymal stem cell constructs

We first evaluated different embedding methods useable for histological analysis and the results showed that among the paraffin, Killik, and acrylic resin the only suitable medium was the latter. Then we employed the acrylic resin to embed the constructs made up of PLLA microfibers and bone marrow-derived human mesenchymal stromal cells, which we then analyzed with Toluidine Blue, PAS and Alcian Blue staining. These constructs, previously analyzed for cell viability by MTT and CCK-8 tests, showed viable/proliferating cells until 6 weeks of culture. The stainings performed on constructs confirmed viability data obtained with SEM and MTT/CCK-8 and supplied other information on the cell behaviors such as the distribution and organization onto the scaffold and the production of extracellular matrix molecules. In conclusion, this methodological study mainly suggests a suitable method to analyze PLLA microfiber/cell constructs, at the same time confirming and enriching the literature data on the compatibility between PLLA microfibers and hMSCs.