Enhanced Growth Activities of Stem Cell Spheroids Based on a Durable and Chemically Defined Surface Modification...

Surface modification layers are needed for the precise definition of surface chemistries and are equally important for durable and stable adhesive properties to ensure long-term stability and effective performance for biotechnological applications. This study demonstrates a robust modification layer that is synthesized based on chemical vapor deposition copolymerization, and the resultant coating layer is composed of the side-by-side presentation of N-hydroxysuccinimide ester and maleimide functionalities with a controlled ratio to define the immobilization accessibility of chitosan and growth factor protein (FGF-2) molecules on the substrate surface for enhancing cellular activities of stem cells. Characterizations of the copolymer modification layer showed excellent durability, including adhesive strength and thermal stability, and the layer is free of concerns for delamination and/or unacceptable deformation/debris formation that can cause potential toxicity to the surrounding biological environment. Modifications using the copolymer layer on the cell culture surface have demonstrated synergistic activity by chitosan to support the formation of spheroids and by FGF-2 to enhance the proliferation of human adipose-derived stem cells (ADSCs) within the spheroids while increasing the spheroid size and cell numbers. Healthy and flourishing growth activities were discovered for ADSCs on the modified culture surfaces, and the results are useful for potential and related stem cell research and the interfaces of biomaterials.