TY - JOUR A1 - Ingendoh-Tsakmakidis, Alexandra A1 - Mikolai, Carina A1 - Winkel, Andreas A1 - Szafrański, Szymon P. A1 - Flak, Christine S. A1 - Rossi, Angela A1 - Walles, Heike A1 - Stiesch, Meike T1 - Commensal and pathogenic biofilms differently modulate peri-implant oral mucosa in an organotypic model JF - Cellular Microbiology N2 - The impact of oral commensal and pathogenic bacteria on peri-implant mucosa is not well understood, despite the high prevalence of peri-implant infections. Hence, we investigated responses of the peri-implant mucosa to Streptococcus oralis or Aggregatibacter actinomycetemcomitans biofilms using a novel in vitro peri-implant mucosa-biofilm model. Our 3D model combined three components, organotypic oral mucosa, implant material, and oral biofilm, with structural assembly close to native situation. S. oralis induced a protective stress response in the peri-implant mucosa through upregulation of heat shock protein (HSP70) genes. Attenuated inflammatory response was indicated by reduced cytokine levels of interleukin-6 (IL-6), interleukin-8 (CXCL8), and monocyte chemoattractant protein-1 (CCL2). The inflammatory balance was preserved through increased levels of tumor necrosis factor-alpha (TNF-α). A. actinomycetemcomitans induced downregulation of genes important for cell survival and host inflammatory response. The reduced cytokine levels of chemokine ligand 1 (CXCL1), CXCL8, and CCL2 also indicated a diminished inflammatory response. The induced immune balance by S. oralis may support oral health, whereas the reduced inflammatory response to A. actinomycetemcomitans may provide colonisation advantage and facilitate later tissue invasion. The comprehensive characterisation of peri-implant mucosa-biofilm interactions using our 3D model can provide new knowledge to improve strategies for prevention and therapy of peri-implant disease. KW - Aggregatibacter actinomycetemcomitans KW - dental implants KW - host modulation KW - organotypic oral mucosa KW - Streptococcus oralis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323077 VL - 21 ER - TY - JOUR A1 - Lotz, Christian A1 - Schmid, Freia F. A1 - Rossi, Angela A1 - Kurdyn, Szymon A1 - Kampik, Daniel A1 - De Wever, Bart A1 - Walles, Heike A1 - Groeber, Florian K. T1 - Alternative Methods for the Replacement of Eye Irritation Testing JF - ALTEX - Alternatives to Animal Experimentation N2 - In the last decades significant regulatory attempts were made to replace, refine and reduce animal testing to assess the risk of consumer products for the human eye. As the original in vivo Draize eye test is criticized for limited predictivity, costs and ethical issues, several animal-free test methods have been developed to categorize substances according to the global harmonized system (GHS) for eye irritation. This review summarizes the progress of alternative test methods for the assessment of eye irritation. Based on the corneal anatomy and current knowledge of the mechanisms causing eye irritation, different ex vivo and in vitro methods will be presented and discussed with regard to possible limitations and status of regulatory acceptance. In addition to established in vitro models, this review will also highlight emerging, full thickness cornea models that might be suited to predict all GHS categories. KW - eye irritation testing KW - alternatives KW - Draize eye test KW - OECD guideline KW - corneal equivalent Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164444 VL - 33 IS - 1 ER - TY - JOUR A1 - Schmid, Richard A1 - Tarau, Ioana-Sandra A1 - Rossi, Angela A1 - Leonhardt, Stefan A1 - Schwarz, Thomas A1 - Schuerlein, Sebastian A1 - Lotz, Christian A1 - Hansmann, Jan T1 - In Vivo-Like Culture Conditions in a Bioreactor Facilitate Improved Tissue Quality in Corneal Storage JF - Biotechnology Journal N2 - The cornea is the most-transplanted tissue worldwide. However, the availability and quality of grafts are limited due to the current methods of corneal storage. In this study, a dynamic bioreactor system is employed to enable the control of intraocular pressure and the culture at the air-liquid interface. Thereby, in vivo-like storage conditions are achieved. Different media combinations for endothelium and epithelium are tested in standard and dynamic conditions to enhance the viability of the tissue. In contrast to culture conditions used in eye banks, the combination of the bioreactor and biochrom medium 1 allows to preserve the corneal endothelium and the epithelium. Assessment of transparency, swelling, and the trans-epithelial-electrical-resistance (TEER) strengthens the impact of the in vivo-like tissue culture. For example, compared to corneas stored under static conditions, significantly lower optical densities and significantly higher TEER values were measured (p-value <0.05). Furthermore, healing of epithelial defects is enabled in the bioreactor, characterized by re-epithelialization and initiated stromal regeneration. Based on the obtained results, an easy-to-use 3D-printed bioreactor composed of only two parts was derived to translate the technology from the laboratory to the eye banks. This optimized bioreactor facilitates noninvasive microscopic monitoring. The improved storage conditions ameliorate the quality of corneal grafts and the storage time in the eye banks to increase availability and reduce re-grafting. KW - bioreactor KW - corneal endothelium KW - corneal epithelium KW - corneal storage KW - tissue culture Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228620 VL - 13 IS - 1,1700344 ER -