Effect of Immobilized Thiolated Glycosaminoglycans on Fibronectin Adsorption and Behavior of Fibroblasts

Glycosaminoglycans (GAGs) chondroitin sulfate, heparin, hyaluronan, and sulfated hyaluronan are lower and higher thiolated to enable a one-step covalent modification of gold or vinyl-terminated surfaces. Measurements of water contact angle and zeta potentials reveal that sulfated GAG-modified surfaces are more wettable and possess a negative surface potential. Additionally, higher thiolated GAGs (tGAGs) exhibit increased wettability and higher surface roughness. Fibronectin (FN) adsorption increases with sulfation degree of tGAGs. The tGAG-functionalized surfaces with higher degree of sulfation promote fibroblast adhesion most under serum-free conditions. The preadsorption of FN allows for more cell adhesion on tGAG surfaces. Metabolic activity measurements show that cell growth is enhanced for tGAGs up to a certain thiolation degree. Overall, thiolation of GAGs does not hamper their bioactivity toward proteins and cells, which make them highly interesting for biomimetic surface modification of implants and tissue engineering scaffolds.