Purpose: The objectives of this in vitro study were (1) to determine whether a commercially available collagen membrane (CM) or human demineralized freeze‐dried bone (DFDB) particles adversely affected viability or function in cultured osteoblasts through oxidative stress, and, if so, (2) to determine whether N‐acetyl cysteine (NAC) successfully prevented loss of viability and dysfunction in osteoblasts.
Materials and methods: Rat calvaria‐derived osteoblasts were seeded onto polystyrene and commercially available CM (Cytoplast®) or DFDB (DynaGraft™) with or without pretreatment with NAC solution. The osteoblastic response was evaluated using a flow cytometric cell viability assay, measurement of attached viable cell number, quantification of reactive oxygen species (ROS) and alkaline phosphatase (ALP) staining.
Results: The percentage of viable cells on CM was <50% at 24 h after seeding. However, this increased to 70% by pretreatment with NAC. The numbers of attached osteoblasts on DFDB remained at 60% the level of that on polystyrene at 24 h after seeding, but increased to up to 90% the level of that on polystyrene with NAC pretreatment. Although collagen materials increased intracellular ROS generation 1.5–5 times that with polystyrene, this was significantly reduced by NAC pretreatment. The percentage of the ALP‐positive area was consistently 7% or less on CM and DFDB at days 7 and 14, which was restored by NAC pretreatment up to 60% or more.
Conclusions: Commercially available CM and DFDB impaired osteoblastic viability and function and markedly increased intracellular ROS, indicating an oxidative stress‐mediated negative impact on osteoblasts. Pretreatment with NAC substantially alleviated these cytotoxic effects.
To cite this article:
Yamada M, Kojima N, Att W, Minamikawa H, Sakurai K, Ogawa T. Improvement in the osteoblastic cellular response to a commercial collagen membrane and demineralized freeze‐dried bone by an amino acid derivative: an in vitro study.
Clin. Oral Impl. Res. 22, 2011; 165–172.
doi: 10.1111/j.1600‐0501.2010.01975.x