Invited Paper BI-WeM8
Engineered Surfaces for Stem Cell Expansion

Wednesday, December 10, 2014, 10:20 am, Room Milo

Control over biomolecule-material and cell-material interactions is critical to the performance of designed surface coatings in a broad range of applications including cell culture materials, implantable biomedical devices and biosensors. Three key design features for materials used in the expansion of cells is that the materials should have very low non-specific protein adsorption, the coatings should be covalently attached to the substrate and should contain covalently attached, highly specific ligands to mediate cell attachment. For cell therapy applications, these materials should be able to function effectively in cell culture media which is chemically defined and animal product free (i.e. serum-free). We have developed a platform coating approach¹, which in one step, results in coatings with very low non-specific protein adsorption, i.e. no initial chemical functionalisation or priming steps are required. In addition, the coatings also contain functional groups onto which cell attachment ligands such as peptides can be chemically attached. The approach can be used to produce coatings on many different formats of interest, such as multiwall plates, tissue culture flasks and microcarrier particles. Microcarrier particles are particularly attractive for application in stirred tank and wavebag-type bioreactors

In this study we have prepared a number of synthetic polymer coatings using a platform grafting from approach to produce materials for the culture of cells. Coatings were formed using a grafting from approach from a monomer feed comprising 10 mole percent acrylic acid and 90 mole percent acrylamide. Coatings were found to be similar in composition to the monomer feed ratio, highly swelling. Characterisation was carried out using X-ray photoelectron spectroscopy and atomic force microscopy. Coupled to these coatings was a cyclic peptide (cRGDfK) which interacts in a highly specific manner with αvβ3 integrins only. These surfaces were found to be highly suitable for the attachment and growth of murine L929 fibroblasts, bone marrow derived human mesenchymal stem cells (hMSCs) and human embryonic stem cells (hESCs). Furthermore, in the case of hMSCs the surfaces were used to expand the cells over three passages in three different media (two were serum free). The hMSCs were characterised by their ability to differentiate into adipocytes, osteocytes and chondrocytes as well as maintenance of cell surface markers typically used to define hMSCs.

References

^1. Ameringer, T., Meagher, L., Thissen, H., Pasic, P., Styan, K., Process for Modifying a Polymeric Surface, WO 2014/000052 A1, 3January 2014