No abstract

We investigated the effect of cold plasma on human skin by detecting molecules for growth and apoptosis, and found that both processes are dependent on treatment time. Therefore, this approach offers promising results for further applications of cold plasma in clinical dermatology.

Background: Platelet-rich plasma (PRP) is widely used in sports medicine. However, neither preparation nor parameters for clinical application, such as concentration, timing, and number of applications, are standardized, making research and clinical utilization challenging. Purpose: To investigate the effect of varying doses of PRP powder in terms of different concentrations, timing, and number of applications on human chondrocytes in a reproducible cell culture model. Study Design: Controlled laboratory study. Methods: A standardized lyophilized platelet growth factor preparation (PRP powder) was used to stimulate human chondrocytes. Chondrocytes were cultivated for 2 weeks with different stimulation frequencies (2×, 3×, 6×) and different concentrations of PRP powders (0.5%, 1%, 5%). Cell proliferation and metabolic cell activity were analyzed on days 7 and 14. Phenotypic changes were visualized through live-dead staining. Chondrogenic differentiation was quantified with enzyme-linked immunosorbent assay to assess the synthesis of procollagen types 1 and 2. Furthermore, sulfated proteoglycans and glycosaminoglycans were analyzed. Results: Human chondrocytes exhibited a significant dose- and time-dependent increase after 14 days in cell number (1% and 5% PRP powder vs unstimulated control: 7.95- and 15.45-fold increase, respectively; 2× vs 6× stimulation with 5% PRP powder: 4.00-fold increase) and metabolic cell activity (1% and 5% PRP powder vs unstimulated control: 3.27-fold and 3.58-fold change, respectively). Furthermore, cells revealed a significant increase in the amount of bone-specific procollagen type 1 (14 days, 1.94-fold) and sulfated glycosaminoglycans (14 days, 2.69-fold); however, no significant change was observed in the amount of cartilage-specific collagen type 2. Conclusion: We showed that chondrocytes exhibit a significant dose- and time-dependent increase in cell number and metabolic cell activity. The standardized use of growth factor concentrates in cell culture models can contribute to clinical knowledge in terms of dosage and timing of PRP applications. Clinical Relevance: Problems with PRP, such as the absence of standardization, lack of consistency among studies, and unknown dosage, could be solved by using characterized PRP powder made by pooling and lyophilizing multiple platelet concentrates. The innovative PRP powder generates new possibilities for PRP research, as well as for the treatment of patients.

With the development of plasma sources generating nonthermal plasmas at atmospheric pressure the applications broaden enormously, especially in the medical field. While earlier applications of physical plasma on biological matter focused on inactivation of microorganisms, the latest studies have revealed a modulation of eukaryotic cells by the same type of plasma. The aim of this study was to elucidate molecular mechanisms triggered by non-thermal plasma in human oral mucosa. Ex vivo biopsies were treated directly with the cold atmospheric pressure plasma jet kinpenMED and analyzed for distinctive markers of proliferation, apoptosis, DNA damage, and differentiation. Moreover, secreted cytokines and growth factors were measured in the supernatant. These results revealed stimulating effects indicated by proliferation consolidated by secretion of VEGF. We also proved that these effects were mediated into deeper layers of the mucosa, without harming the cells on top of the treated samples. DNA damage detected as H2A.X-immunoreactivity was nearly constant between all samples. Our study revealed for the first time that human oral mucosa can be modulated by plasma treatment. Molecular markers for both cell damage and proliferation helped to identify the mechanisms triggered by plasma treatment. Moreover, our results strengthen a safe application of the kinpenMED on human oral tissue. Further studies on diseased skin are being performed in order to proceed towards a safe introduction of plasma medicine into the clinics.