Induction of Apoptosis and Dysfunction in Cultured Osteoblasts by Collagen Dressing Sponge and Its Improvement by N-acetyl Cysteine
2010 Volume 23 Issue 1 Pages 3-11
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2010 Volume 23 Issue 1 Pages 3-11
Background: Osteocompatibility of dressing collagen sponge is crucial for successful socket preservation before implant placement. Recently, adverse effects of implantable devices and materials were found to be associated with an excessive generation of reactive oxygen species (ROS). N-acetyl cysteine (NAC) can detoxify such cytotoxic materials.
Objectives: This study determined whether commercially available collagen dressing sponge shows any cytotoxic effects on osteoblasts, and if so, whether treating the material with NAC diminishes the cytotoxicity.
Methods:Rat calvarial osteoblasts were seeded on culture-grade polystyrene dishes or on a bovine-driven atelocollagen dressing sponge (TERUPLUG® , Olympus Terumo Biomaterial Corp., Tokyo) soaked in saline or NAC solution. Cytotoxicity of the materials was evaluated by a cell viability analysis, attached cell quantification, an intracellular ROS fluorescent quantification and a confocal laser microscopic observation with anti-ROS and cytoskeletal fluorescent staining after 24-h incubation. Cell function on collagen sponge was assessed by ALP staining at day 5 of culture.
Results:The percentage of viable cells was below 50% on the collagen dressing sponge tested. However, pretreating the collagen sponge with NAC increased the percentage of viable cells up to 70% on material. The collagen sponge induced osteoblastic functional disorders as shown by small attached cell number, impaired cellular adhesion and suppressed alkaline phosphatase activity on materials, which was restored by pretreating the material with NAC. NAC prevented extraordinary generation of intracellular reactive oxygen species on the collagen sponge.
Conclusion:Culturing rat calvarial osteoblasts on commercial collagen dressing sponge resulted in devastating damage to cell viability and function. Application of NAC greatly reduced the cytotoxicity for the collagen dressing sponge tested, suggesting that this molecule is useful for improving the biocompatibility of biomaterials.
