Biomimetic microspheres for 3D mesenchymal stem cell culture and characterization.

• Microspheres are flexible biomimetic 3D environments that can be freely remodeled by cells. • Microspheres are a versatile system for a wide variety of cellular analyses. • Cells grown in the microspheres have good proliferation rates. • Cells form aggregates and surround the fibronectin coated microspheres. • Hyaluronic acid coating triggers cell proliferation but hinders cell adhesion. Stem cells reside in niches, specialized microenvironments that sustain and regulate their fate. Extracellular matrix (ECM), paracrine factors or other cells are key niche regulating elements. As the conventional 2D cell culture lacks these elements, it can alter the properties of naïve stem cells. In this work we designed a novel biomimetic microenvironment for cell culture, consisting of magnetic microspheres, prepared with acrylates and acrylic acid copolymers and functionalized with fibronectin or hyaluronic acid as ECM coatings. To characterize cell proliferation and adhesion, porcine mesenchymal stem cells (MSCs) were grown with the different microspheres. The results showed that the 3D environments presented similar proliferation to the 2D culture and that fibronectin allows cell adhesion, while hyaluronic acid hinders it. In the 3D environments, cells reorganize the microspheres to grow in aggregates, highlighting the advantages of microspheres as 3D environments and allowing the cells to adapt the environment to their requirements. [ABSTRACT FROM AUTHOR]