Evaluation of Adhesion, Growth and Differentiation of Human Umbilical Cord Stem Cells to Osteoblast Cells on PLA Polymeric Scaffolds

Abstract

Tissue engineering is used for regenerating bioartificial tissues using suitable cells and biocompatible scaffold materials. The present study aims to prepare poly (lactic acid) (PLA) nanoparticles as an extracellular matrix to use in bone tissue engineering. For this purpose, the stem cells originating from the human umbilical cord were extracted and their adhesion, growth, and osteoblastic differentiation on the PLA scaffold were studied. First, the PLA nano-scaffold was fabricated by solvent casting/salt leaching method, and then its properties including formation, surface properties, porosity, pore size, pore distribution, biocompatibility, and biodegradability were evaluated. After extracting mesenchymal stem cells (MSCs) from the umbilical cord of human embryos, they were cultured on the scaffold, and then flow cytometry was used to prove their stemness. The morphological properties of the scaffold and differentiated cells attached to it were investigated using scanning electron microscopy (SEM), Alizarin red, and Von kossa staining. The results of SEM and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests for evaluating its biocompatibility showed that this scaffold has suitable surface properties for cell growth and proliferation. The result of flow cytometry demonstrated more than 90% expression of CD105 and CD90 markers (MSCs markers) and no expression of CD45 (hematopoietic marker) on the cell’s surface. The images of Alizarin red staining, Von kossa staining, and SEM confirmed calcium deposition on the scaffold containing cells differentiated to osteoblasts. This study showed that MSCs can adhere, proliferate and differentiate to bone cells (osteoblasts) on PLA scaffold in vitro. Thus, additional experiments on this scaffold should be done for regenerating bone tissues in vivo.