In Vitro Effects of Extracorporeal Shockwave Therapy (ESWT) on Proliferation and Metabolic Activity of Adult Human Keratinocytes

Abstract

Background: The objective of the presented study is to investigate in vitro effects of low energy extracorporeal shockwave therapy (ESWT) on the keratinocytes and their metabolic and proliferative properties for their therapeutic applications. Materials: Primary culture of keratinocytes was isolated from clinical samples and after passaging into 12 flasks exposed to the various number of ESWT impulses (n=25, 50 and100impulses) in combination with several frequencies (1, 3 or 5Hz) and distances from the applicator head (5, 6 or 7cm with corresponding energy flux densities (EFD)=0.04, 0.025 and 0.015 mJ/mm2, respectively) using modified water bath at constant temperature 37°C. Flasks were assigned to receive one combination of treatment parameters. The individually tested distances/EFD with the various impulse numbers and frequencies were summarised to experimental series. Cell viability was measured using trypan blue, cell cytotoxicity was measured using lactate dehydrogenase assay, and cell metabolic activity was measured by level of glucose metabolism. Results: Our results indicate that low energy ESWT has both cytotoxic and stimulating effects on the keratinocytes. These effects depend on number of impulses, distance from the applicator head, and frequency. A proliferationstimulating effect and a higher viable cell count could be observed for a distance of 5 cm with 100 impulses at 1 Hz and EFD=0.04 mJ/mm2. Conclusion: Our results indicate that ESWT (EFD=0.04 mJ/mm2, 100 impulses, 1Hz at 5 cm) augmented proliferative capacity of keratinocytes in vitro. These promising results grant further investigation and have practical potential in keratinocyte research and production.