Osteogenic Induction of Human Mesenchymal Stem Cells by Cold Atmospheric Argon Plasma

摘要

Cold plasmas induce angiogenesis, enhance coagulation and wound healing, and selectively ablate microbes without harming eukaryotes. Work on bone tissue has been minimal; initial studies show enhanced osseointegration, increased gene transcription, and mesenchymal stem cell growth. Mesenchymal stem cell osteoblastic differentiation is required for bone formation and healing. The present study employs a novel device to assess whether cold argon plasma induces osteogenic differentiation of human mesenchymal stem cells. Human mesenchymal stem cells were exposed to five conditions: growth, osteogenic stimulation, non-ionized argon gas, argon plasma, and argon plasma with osteogenic stimulation. Known osteoblastic differentiation markers (alkaline phosphatase, osteocalcin, RANKL) were assessed on days 1,10, and 28. Cellular DNA production was measured for normalization. Novel dielectric barrier discharge plasma device parameters were as follows: energy 5J, flow rate 30 psig/min, distance 22 mm, and duration 30 sec. Alkaline phosphatase level was decreased compared to other treatments, with varying significance. Nonionized argon gas significantly increased alkaline phosphatase (p < 0.0014) compared to other groups. Osteogenic stimulation did not result in difference from growth. Changes in osteocalcin or receptor activator of nuclear factor kappa-B ligand (RANKL) were not observed. A definitive claim regarding the ability of cold argon plasma to induce osteoblastic differentiation cannot be made. Lack of ^-glycerophosphate addition on day 14 prevented osteogenic media from responding as expected. Interestingly, non-ionized argon gas significantly increased alkaline phosphatase production. This novel finding, possibly due to argon shielding or shear force production, merits further study.