Cell culture plastic ware was obtained from Nunc (Wiesbaden, Germany), BD (Heidelberg, Germany) and Greiner (Frickenhausen, Germany). Modified Minimal Essential Medium (α-MEM), phosphate buffered saline (PBS), trypsin and penicillin/streptomycin antibiotics were from Biochrom (Berlin, Germany), McCoy’s 5A medium was purchased from BioConcept (Allschwil, Switzerland). Fetal bovine serum (FBS) was obtained from BioWest (via Geyer, Hamburg, Germany). Ascorbic acid, β-glycerophosphate, alendronate and zolendronate were obtained from Sigma (Taufkirchen, Germany). The synthesis and characterization of sulfated hyaluronan derivatives were performed as previously described