Infrared reflection measurements of the half-filled two-dimensional organic conductors κ-(BEDT-TTF)2Cu[N(CN)2]BrxCl1−x were performed as a function of temperature (5 K < T < 300 K) and Br-substitution (x = 0%, 40%, 73%, 85%, and 90%) in order to study the metal-insulator transition. We can distinguish absorption processes due to itinerant and localized charge carriers. The broad mid-infrared absorption has two contributions: transitions between the two Hubbard bands and intradimer excitations from the charges localized on the (BEDT-TTF)2 dimer. Since the latter couple to intramolecular vibrations of BEDT-TTF, the analysis of both electronic and vibrational features provides a tool to disentangle these contributions and to follow their temperature and electronic-correlations dependence. Calculations based on the cluster model support our interpretation.

Nonthermal treatment with cold atmospheric plasma (CAP) is a promising option for local treatment of chronic-inflammatory and precancerous lesions as well as various mucosal cancer diseases, besides its primary indication for wound healing and antiseptics. Atmospheric pressure plasma jets (APPJs) are versatile plasma sources, some of which are well-characterized and medically approved. The characterization of APPJs, however, is often based on the treatment of simple solutions or even studies on the plasma effluent itself. To better assess the in vivo effects of CAP treatment, this study aims to recapitulate and study the physicochemical tissue-level effects of APPJ treatment on human primary mucosal tissue and tissue models. High resolution on-tissue infrared (IR) thermography and a first-time-performed spatially resolved optical emission spectroscopy (OES) of the APPJ emissions did not identify potentially tissue-harming effects. In this study, electron-spinresonance (ESR) spectroscopy on human tissue samples, treated with different CAP doses, enabled the measurement and the distribution of CAP-derived radicals in the tissues. The results correlate plasma dosage and the generation of radical species with cell viability and cell proliferation of primary human fibroblasts while demonstrating apoptosis-independent antiproliferative cell effects. Moreover, a dose-dependent increase of cells in the G1 phase of the cell cycle was observed, stressing the likely important role of cell cycle regulation for antiproliferative CAP mechanisms. This study introduces suitable methods for CAP monitoring on tissues and contributes to a better understanding of tissue-derived plasma effects of APPJs.

Generation and recombination processes of plasma‐induced radicals in plasma polymers are investigated using ESR, which provides valuable information about radicals in thin polymer films. The polymer films are prepared by means of r.f. plasma polymerization of c‐C4F8. Radical numbers and densities of fluorocarbon plasma polymer coatings of different thicknesses are measured by extrapolating mixed‐order recombination processes. The kinetics of radical generation in plasma polymer films is modeled using the results of the time‐dependent radical decay studies. The life times, line‐broadening effects, activation energies, and the temperature behavior of the radicals are discussed.

(1) Background: Cervical intraepithelial neoplasia (CIN) of long-term persistence or associated with individual treatment indications often requires highly invasive treatments. These are associated with risks of bleeding, infertility, and pregnancy complications. For low- and middle-income countries (LMICs), standard treatment procedures are difficult to implement and manage. We characterized the application of the highly energized gas “noninvasive physical plasma” (NIPP) for tissue devitalization and the treatment of CIN. (2) Methods: We report the establishment of a promising tissue devitalization procedure by NIPP application. The procedure was characterized at the in vitro, ex vivo and in vivo levels. We performed the first prospective, single-armed phase-IIb trial in 20 CIN1/2 patients (NCT03218436). (3) Results: NIPP-treated cervical cancer cells used as dysplastic in vitro model exhibited significant cell growth retardation due to DNA damage, cell cycle arrest and apoptosis. Ex vivo and in vivo tissue assessments showed a highly noninvasive and tissue-preserving treatment procedure which induces transmucosal tissue devitalization. Twenty participants were treated with NIPP and attended a 24-week follow-up. Treatment success was achieved in 19 (95%) participants without postinterventional complications other than mild to moderate discomfort during application. (4) Conclusions: The results from this study preliminarily suggest that NIPP could be used for an effective and tissue-preserving treatment for CIN without the disadvantages of standard treatments. However, randomized controlled trials must confirm the efficacy and noninferiority of NIPP compared to standard treatments.

The control of surface properties is a substantial step in the development and improvement of biomaterials for clinical applications as well as for their use in tissue engineering. Interaction of the substrate surface with the biochemical or biological environment is crucial for the outcome of the applied biomaterial and therefore should meet specific requirements regarding the chemical composition, wettability, elasticity, and charge. In this study, we examined the effect of chemical groups introduced by low pressure plasma treatments of polystyrene surfaces on the cell behavior of primary human mesenchymal stem cells (hMSCs) and dermal microvascular endothelial cells (hDMECs). X-ray photoelectron spectroscopy analysis and contact angle measurements were employed to evaluate ammonia-, carbon dioxide-, and acrylic acid-plasma modifications to substrate surfaces. HMSCs and hDMECs were analyzed simultaneously to identify the most suitable surface functionalization for each cell type. Significantly higher cell proliferation was detected on ammonia plasma-treated surfaces. Cell-material interaction could be shown on all created interfaces as well as the expression of typical cell markers. Hence, the applied plasma treatment presents a suitable tool to improve culture condition on polystyrene for two important cell types (hMSCs and hDMECs) in the field of tissue engineering.

Non‐thermal plasma treatment is one of the promising options for local anti‐neoplastic treatment of dysplastic lesions and early intraepithelial cancer. Primarily, the antiproliferative properties are driven through the generation of reactive oxygen and nitrogen species. In this study, we investigated the amount and distribution of reactive species generated by a non‐thermally operated electrosurgical argon plasma source using electron spin resonance (ESR) spectroscopy. During the plasma treatment of both, aqueous solution and solid human preputial tissue an increasing amount of different oxygen‐ and carbon‐centered radicals was detected. However, and most probably due to spin trap degradation by the high energy input and the increase of reactive components in aqueous solution, the ESR signal decreased after treatment times exceeding 10 s.

Cold atmospheric plasma (CAP) treatment is developing as a promising option for local anti-neoplastic treatment of dysplastic lesions and early intraepithelial cancer. Currently, high-frequency electrosurgical argon plasma sources are available and well established for clinical use. In this study, we investigated the effects of treatment with a non-thermally operated electrosurgical argon plasma source, a Martin Argon Plasma Beamer System (MABS), on cell proliferation and metabolism of a tissue panel of human cervical cancer cell lines as well as on non-cancerous primary cells of the cervix uteri. Similar to conventional CAP sources, we were able to show that MABS was capable of causing antiproliferative and cytotoxic effects on cervical squamous cell and adenocarcinoma as well as on non-neoplastic cervical tissue cells due to the generation of reactive species. Notably, neoplastic cells were more sensitive to the MABS treatment, suggesting a promising new and non-invasive application for in vivo treatment of precancerous and cancerous cervical lesions with non-thermally operated electrosurgical argon plasma sources.

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