Self-assembly immobilization of hyaluronan thiosemicarbazone on a gold surface for cell culture applications

Hyaluronan (HA)-fixed layers were successfully prepared on a gold coated glass plate via self-assembly chemisorption of HA derivatives whose aldehydic reducing ends were selectively modified with thiosemicarbazide (TSC). Quartz crystal microbalance analysis and X-ray photoelectron spectroscopy suggested formation of the HA layers on the gold surfaces through spontaneous S-Au interaction, resulting in stability in aqueous culture medium. Biological functions of the HA layers were investigated by cell adhesion assay using mouse fibroblast cells (NIH-3T3). Cell attachment to the hydrophilic HA surface (water contact angle ≈ 11°) was far superior to cell attachment to a sugar-free, hydrophobic gold substrate (≈57°), while a spin-coated film composed of water-soluble, TSC-free HA molecules made little contribution to cell adhesion. After 48 h incubation, the NIH-3T3 cells proliferated well only on the HA layers and retained their original viability. This novel approach to surface glyco-modification with biocompatible HA is expected to have potential applications as a biofunctional scaffold for cell culture applications.