in alginate beads. Contrary results were shown by a study of Ince and colleagues or Charalambous and co- workers.2,19 In the study of Ince and colleagues, human osteoblasts and endothelial cell were incubated with different concentrations of polyhexanide for 6 hours. Already a low concentration of 0.0006% of polyhexanide demonstrated a signiﬁcant decrease of total cell number and viability.19 In the study of Sch- aumburger and co-workers, cultured chondrocytes were treated with different concentrations of polyhex- anide, hydrogen peroxide, and betaisodona. In all treatment groups, a decrease of vital cells and of total cell count were detected.5 In comparison with the results of the present study, our data showed no signiﬁcant differences of cell numbers between control and antiseptic-treated chondrocytes. An explanation is very likely that chondrocytes embedded in alginate beads show a higher and clinically more relevant barrier against the injurious effects of antiseptic solutions. Monolayer-cultured chondrocytes do not have any barrier against toxic solutions. In summary, polyhexanide has more toxic potential than hydrogen peroxide. Both antiseptics inhibit the proteoglycan synthesis of human chondrocytes. Based on the fact that the cell number and morphology were not altered by the substances at the examined concen- trations, the lower intensity of Alcian blue staining of treated chondrocytes indicates a direct decrease of cartilage speciﬁc matrix synthesis by polyhexanide more than by hydrogen peroxide and control. References 1 Armstrong RW, Bolding F, Joseph R. Septic arthritis following arthroscopy: clinical syndromes and analysis of risk factors. Arthroscopy 1992;8:213–31. 2 Charalambous CP, Tryfonidis M, Sadiq S, Hirst P, Paul A. Septic arthritis following intra-articular steroid injection of the knee — a survey of current practice regarding antiseptic Ro¨hner et al. Polyhexanide and hydrogen peroxide inhibit proteoglycan synthesis technique used during intra-articular steroid injection of the knee. Clin Rheumatol 2003;22:386–90. 3 von Essen R, Savolainen HA. Bacterial infection following intra-articular injection — a brief review. Scan J Rheumatol 1989;18:7–12. 4 Kalteis T, L u¨ring C, Schaumburger J, Perlicl L, Ba¨this H, Grifka J. Gewebetoxizit a¨t lokaler Antiseptika. Z Orthop 2003;141:233–8. 5 Schaumburger J, Beckmann J, Springorum HR, Handel M, Anders S, Kalteis T, et al. Toxitita¨t lokaler Antiseptika auf Chondrozyten in vitro. Z Orthop Unfall 2010;148:39–43. 6 Riegels-Nielsen P, Frimodt-M o¨ller N, Jensen J. Rabbit model of septic arthritis. Acta Orthop Scand 1987;58:14–9. 7 Ryan MJ, Kavanagh R, Wall PG, Hazleman BL. Bacterial joint infection in England and Wales: analysis of bacterial isolates over a four year period. Br J Rheumatol 1997;36:370–3. 8 Smith M. Arthroscopic treatment of the septic knee. Arhtroscopy 1986;2:30–4. 9 Muir H. The chondrocyte, architect of cartilage. Biomechanics, structure, function and molecular biology of cartilage matrix macromolecules. Bioessays 1995;17:1039–48. 10 Goldring MB. The role of the chondrocytes in osteoarthritis. Arthritis Rheum 2000;43:1916–26. 11 Newman AP. Articular cartilage repair. Am J Sports Med 1998;26:309–24. 12 de Crombrugghe B, Lefebvre V, Behringer RR, Bi W, Murakami S, Huang W. Transcriptional mechanisms of chondrocytes differentiation. Matrix Biol 2000;9:389–94. 13 Goldring MB. Update on the biology of the chondrocyte and new approaches to treating cartilage disease. Best Pract Res Clin Rheumatol 2006;20:1003–25. 14 M u¨ller G, Kramer A. Effect of selected wound antiseptics on adult articular cartilage (bovine sesamoid bone) in the presence of Escherichia coli and Staphylococcus aureus. J Orth Res 2005;23:127–33. 15 Bates EJ, Johnson CC, Lowther DA. Inhibition of proteogly- can synthesis by hydrogen peroxide in cultured bovine articular cartilage. Biochimica Biophysica Acta 1984;838:221–8. 16 R o¨hner E, Detert J, Kolar P, Hocke A, N’Guessan P, Matziolis G, et al. Induced apoptosis of chondrocytes by Porphyromonas gingivalis as a possible pathway for cartilage loss in rheumatoid arthritis. Cal Tiss Int 2010;87:333–40. 17 Pischon N, R o¨hner E, Hocke A, N’Guessan P, M u¨ller HC, Matziolis G, et al. Effects of Porphyromonas gingivalis on cell cycle progression and apoptosis of primary human chondro- cytes. Ann Rheum Dis 2009;68:1902–7. 18 Stutz G, Ga¨chter A. Diagnostik und stadiengerechte Therapie von Gelenkinfekten. Unfallchirurg 2001;104:682–6. 19 Ince A, Sch u¨tze N, Hendrich C, Jakob F, Eulert J, L o¨hr JF. Effect of polyhexanide and gentamicin on human osteoblasts and endothelial cells. Swiss Med Wkly 2007;137:139–45. Journal of Histotechnology 2011 VOL. 34 NO. 1 39