Umbilical cord blood (UCB) serves as a source of hematopoietic stem and progenitor cells (HSPCs) utilized in the regeneration of hematopoietic and immune systems, forming a crucial part of the treatment for various benign and malignant hematological diseases. UCB has been utilized as an alternative HSPC source to bone marrow (BM). Although the use of UCB has extended transplantation access to many individuals, it still encounters significant challenges in selecting a histocompatible UCB unit with an adequate cell dose for a substantial proportion of adults with malignant hematological diseases. Consequently, recent research has focused on developing ex vivo expansion strategies for UCB HSPCs. Our results demonstrate that co-cultures with the investigated mesenchymal stromal cells (MSCs) enable a 10- to 15-fold increase in the cellular dose of UCB HSPCs while partially regulating the proliferation capacity when compared to HSPCs expanded with early acting cytokines. Furthermore, the secretory profile of UCB-derived MSCs closely resembles that of BM-derived MSCs. Moreover, both co-cultures exhibit alterations in cytokine secretion, which could potentially impact HSPC proliferation during the expansion process. This study underscores the fact that UCB-derived MSCs possess a remarkably similar supportive capacity to BM-derived MSCs, implying their potential use as feeder layers in the ex vivo expansion process of HSPCs.

The interaction of mesenchymal stromal cells (MSC) in co-cultures with hematopoietic progenitor cells (HPC) in ex-vivo models induce the secretion of pro-inflammatory protein factors and influences HPC cell proliferation and differentiation processes. Different studies have shown the quantification of these biomarkers in other conditioned media using an ELISA and Luminex™ type immunoassay format. In this paper, we developed real-time quantification of biomarkers in conditioned media of these cells in co-cultures from bone marrow, umbilical cord blood, and Wharton's jelly sources using surface plasmon resonance imaging (SPRi). We show the detection and quantification of CCL2, CCL5, bFGF, IL-6, IL-8 and VEGF proteins with high sensitivity and specificity. SPRi can be used with a real-time analysis methodology and could be considered a tool for biomarker assays.