Co-culture of Umbilical Cord-derived Hematopoietic and Mesenchymal Stem Cells on Protein-Coated poly-L-Lactic Acid Nanoscaffolds

Background and purpose: Umbilical cord blood (UCB) is a source of Hematopoietic stem cells (HSCs) and has received a lot of attention due to its availability, renewal capacity, proliferation rate, and differentiation potential. The main limitation of using these cells is their low quantity in one unite of UCB. To overcome this, HSCs co-culturing with UCB derived mesenchymal cells (MSCs) is a practical approach. The purpose of this study was the expansion of HSCs together with UCB derived MSCs on a three-dimensional poly L- lactic acid coated with fibronectin. Materials and methods: In this experimental study, after isolation of CD133+ from UCB cells using MACS method, the purity of the isolated cells was carried out by flow cytometry. Then, the cells were seeded on PLLA scaffold coated with fibronectin in presence of mesenchymal cells (group I), the PLLA scaffold in presence of mesenchymal cells (group II), and PLLA scaffold (group III). The proliferation rate, colonization potential and bio-compatibility of the cells were studied using a hemocytometer, CFU assay, and MTT, respectively. Results: The cells co-cuthured with PLLA-Fn scaffold (group I) had a higher proliferation rate of CD133 stemness marker compared to other groups. Also, the colonization of the cells and scaffold׳s biocompatibility was significantly higher in this group compared to other groups. (P <0.05). Conclusion: The study proved that the optimal 3D culture system in PLLA scaffold coated with fibronectin co-cultured with MSCs could reproduce minimum differentiation of CD133 + cells.