A study on polysialic acid as a biomaterial for cell culture applications

Polysialic acid (PSA) was investigated for its applicability as coating material for mammalian cell cultivation. PSA is involved in post-translational modification of the vertebrate neural cell adhesion molecule (NCAM). It is biocompatible and degradation-controlled. Thus, it becomes interesting for use as a coating and scaffold material for tissue engineering applications, especially for peripheral nerve regeneration. As a preliminary study of the use of PSA as scaffold material it was tested in its soluble form as coating material. The cytotoxicity was investigated and compared to another polysaccharide beta-glucan, to widely used coating substances (collagen I, poly-L-lysine, hyaluronic acid) and uncoated tissue culture plastic material. The interactions between the modified cell culture surface and the cells were investigated using a model liver cell line Hep-G2 and a neurobiological cell line PC-12. The PSA coating itself was analyzed by immunoanalysis. Viability of the cells was investigated by the MTT assay. The number and distribution of adhered cells were studied by cell nuclei staining. Furthermore, the differentiation status of the PC-12 cells was monitored, as well as glucose and lactate levels in the cell culture medium from the Hep-G2 cells. Comparable viability and similar numbers of attached cells were observed. Growth in cell clusters was observed for PSA, beta-glucan, and hyaluronic acid coated materials. In general, the results indicate that PSA is comparable to other well-established coating materials (e.g. collagen I, hyaluronic acid, and poly-L-lysine). Moreover, as a key substance in vertebrate development it offers interesting features for nerve regeneration, especially as an insoluble, modified scaffold material.