comparison of the Growth and Differentiation of the Human Umbilical Cord Mesenchymal Stem Cells on the Poly-L-lactic acid/Hydroxyapatite Composite Scaffold with Pure Poly-L-lactic Acid Scaffold

Background and Natural bone is a combination of polymer and biological apatite, therefore, the composite scaffolds made of polymers and bioactive ceramics have found wide applications in bone tissue engineering studies. Among various polymers, the poly-L-lactic acid (PLLA) and hydroxyapatite (HA) have attracted much attention due to their optimal properties. In this study, using PLLA polymer and hydroxyapatite (which is similar to human bone mineral component) three-dimensional composite scaffolds were developed by Electrospinning Method. Then the behavior of human umbilical cord mesenchymal stem cells (MSCs) was investigated on the scaffolds. The aim of this research was to develop an appropriate bioactive and functional scaffold for bone tissue engineering. In this study mesenchymal stem cells were isolated from the human umbilical cord. The cells were cultured on both PLLA and PLLA/HA (10%) composite polymeric nano scaffolds. Biocompatibility of scaffolds was confirmed by MTT assay. The morphological and cell adhesion characteristics of MSCs on the scaffolds were compared using Scanning Electron Microscopic (SEM) imaging. Finally, the cells were treated with osteogenic differentiation medium for 21 days in order to investigate their differentiation potential on the scaffolds. The differentiation of the stained cells with Alizarin Red and Von Kossa were studied at 7,14 and 21 days after cultivation. SEM studies showed that the surface properties of both scaffolds were desirable and the cells not only had the ability to attach and proliferate better on the nanocomposite scaffolds, but were also in a natural condition morphologically. The comparison of staining results indicated a higher differentiation rate in composite polymeric nano scaffold. The results showed that the PLLA/HA nano scaffold could be a very good candidate for bone tissue engineering.