Date Published: July 6, 2017
Publisher: Public Library of Science
Author(s): Kanako Tominami, Hiroyasu Kanetaka, Shota Sasaki, Takayuki Mokudai, Toshiro Kaneko, Yoshimi Niwano, Sakamuri V. Reddy.
This study was designed to assess the effects of cold atmospheric plasma on osteoblastic differentiation in pre-osteoblastic MC3T3-E1 cells. Plasma was irradiated directly to a culture medium containing plated cells for 5 s or 10 s. Alkaline phosphatase (ALP) activity assay and alizarin red staining were applied to assess osteoblastic differentiation. The plasma-generated radicals were detected directly using an electron spin resonance-spin trapping technique. Results show that plasma irradiation under specific conditions increased ALP activity and enhanced mineralization, and demonstrated that the yield of radicals was increased in an irradiation-time-dependent manner. Appropriate plasma irradiation stimulated the osteoblastic differentiation of the cells. This process offers the potential of promoting bone regeneration.
In a modern society with a large aging population, age-related diseases such as decubitus ulcers and periodontitis caused by a weakened immune system have come to present an important social problem. For instance, periodontitis, an inflammatory disease that causes progressive destruction of tooth-supporting tissues including alveolar bone, root cementum, and periodontal ligaments, affects a large share of humanity worldwide. Periodontitis destroys tooth-supporting tissues and eventually causes tooth loss. Reconstituting lost periodontal structures persists as a difficult medical challenge [1, 2].
Cold atmospheric plasma produces various biologically active reactive species, particularly ROS including H2O2, •OH and •O2-, which are highly reactive radicals or molecules. Various experimental investigations have demonstrated that ROS can affect cell activity, including attenuated proliferation, cell cycle arrest, and increased sensitivity to apoptosis. This study specifically examined short-term effects of plasma irradiation on in vitro cell differentiation and the mineralization of osteoblasts (MC3T3- E1 cells) in relation to ROS generation.
Based on results of this study, we concluded that short-term appropriate plasma irradiation can stimulate osteoblast differentiation. We propose that cold atmospheric plasma irradiation might have clinical potential for accelerating periodontitis healing by promoting bone regeneration and bactericidal action. Future work must be undertaken to clarify the biochemical and electromagnetic mechanisms underlying plasma-induced differentiation of MC3T3-E1 cells.