Three-dimensional expansion using plasma-medium gel with fragmin/protamine nanoparticles and FGF-2 to stimulate adipose-derived stromal cells and bone marrow-derived mesenchymal stem cells

Fragmin/protamine nanoparticles (F/P NPs) have been used as carriers for the preservation and controlled release of fibroblast growth factor (FGF)-2 and various cytokines in human plasma (HP). This study tested an HP-Dulbecco's modified Eagle's medium (DMEM) gel as a three-dimensional (3D) culture for the expansion of adipose tissue-derived multilineage stromal cells (ASCs) and bone marrow-derived mesenchymal stem cells (BMSCs). The growth of these cells improved in 3D culture using low-concentration HP (2%)-DMEM gel with 0.1 mg/mL F/P NPs and 5 ng/mL FGF-2 without animal serum in comparison to two-dimensional (2D) culture using a low-concentration human serum (2%)-DMEM containing 5 ng/mL FGF-2 on F/P NPs-coated plates. ASCs and BMSCs, which were expanded in the low-concentration HP-DMEM gel with F/P NPs and FGF-2, maintained their multilineage potential for differentiation into adipocytes or osteoblasts similar to the 2D cultured cells. Furthermore, flow cytometric analyses showed that the phenotypic markers which were positive for CD44, CD90, and CD105 (>80%) and negative for CD34 and CD45 (<1%) were well maintained in both 2D and 3D cultures after 7 days. Thus, this 3D culture system in low-concentration HP-DMEM gel with F/P NPs and FGF-2 provided an effective and safe method for the expansion of both cell types without using animal serum.