TY - JOUR A1 - Moll, Corinna A1 - Reboredo, Jenny A1 - Schwarz, Thomas A1 - Appelt, Antje A1 - Schürlein, Sebastian A1 - Walles, Heike A1 - Nietzer, Sarah T1 - Tissue Engineering of a Human 3D in vitro Tumor Test System JF - Journal of Visualized Experiments N2 - Cancer is one of the leading causes of death worldwide. Current therapeutic strategies are predominantly developed in 2D culture systems, which inadequately reflect physiological conditions in vivo. Biological 3D matrices provide cells an environment in which cells can self-organize, allowing the study of tissue organization and cell differentiation. Such scaffolds can be seeded with a mixture of different cell types to study direct 3D cell-cell-interactions. To mimic the 3D complexity of cancer tumors, our group has developed a 3D in vitro tumor test system. Our 3D tissue test system models the in vivo situation of malignant peripheral nerve sheath tumors (MPNSTs), which we established with our decellularized porcine jejunal segment derived biological vascularized scaffold (BioVaSc). In our model, we reseeded a modified BioVaSc matrix with primary fibroblasts, microvascular endothelial cells (mvECs) and the S462 tumor cell line For static culture, the vascular structure of the BioVaSc is removed and the remaining scaffold is cut open on one side (Small Intestinal Submucosa SIS-Muc). The resulting matrix is then fixed between two metal rings (cell crowns). Another option is to culture the cell-seeded SIS-Muc in a flow bioreactor system that exposes the cells to shear stress. Here, the bioreactor is connected to a peristaltic pump in a self-constructed incubator. A computer regulates the arterial oxygen and nutrient supply via parameters such as blood pressure, temperature, and flow rate. This setup allows for a dynamic culture with either pressure-regulated pulsatile or constant flow. In this study, we could successfully establish both a static and dynamic 3D culture system for MPNSTs. The ability to model cancer tumors in a more natural 3D environment will enable the discovery, testing, and validation of future pharmaceuticals in a human-like model. KW - bioengineering KW - biomedical engineering KW - tissue engineering KW - biotechnology KW - cultured KW - tumor cells KW - cell culture KW - 3D in vitro models KW - bioreactor KW - dynamic culture conditions KW - tumor test system KW - primary cell isolation KW - BioVaSc KW - decellularization KW - equipment and supplies KW - cellular microenvironment KW - culture techniques KW - cell engineering KW - anatomy KW - physiology KW - molecular biology KW - cellular biology Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132277 UR - http://www.jove.com/video/50460 VL - 78 IS - e50460 ER - TY - JOUR A1 - Votteler, Miriam A1 - Carvajal Berrio, Daniel A. A1 - Pudlas, Marieke A1 - Walles, Heike A1 - Schenke-Layland, Katja T1 - Non-contact, Label-free Monitoring of Cells and Extracellular Matrix using Raman Spectroscopy JF - Journal of Visual Expression N2 - Non-destructive, non-contact and label-free technologies to monitor cell and tissue cultures are needed in the field of biomedical research.1-5 However, currently available routine methods require processing steps and alter sample integrity. Raman spectroscopy is a fast method that enables the measurement of biological samples without the need for further processing steps. This laser-based technology detects the inelastic scattering of monochromatic light.6 As every chemical vibration is assigned to a specific Raman band (wavenumber in cm-1), each biological sample features a typical spectral pattern due to their inherent biochemical composition.7-9 Within Raman spectra, the peak intensities correlate with the amount of the present molecular bonds.1 Similarities and differences of the spectral data sets can be detected by employing a multivariate analysis (e.g. principal component analysis (PCA)).10 Here, we perform Raman spectroscopy of living cells and native tissues. Cells are either seeded on glass bottom dishes or kept in suspension under normal cell culture conditions (37 °C, 5% CO2) before measurement. Native tissues are dissected and stored in phosphate buffered saline (PBS) at 4 °C prior measurements. Depending on our experimental set up, we then either focused on the cell nucleus or extracellular matrix (ECM) proteins such as elastin and collagen. For all studies, a minimum of 30 cells or 30 random points of interest within the ECM are measured. Data processing steps included background subtraction and normalization. KW - tissue engineering KW - label-free analysis KW - raman spectroscopy KW - bioengineering KW - living cells KW - extracellular matrix Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124569 VL - 63 IS - e3977 ER - TY - JOUR A1 - Groeber, Florian A1 - Engelhardt, Lisa A1 - Lange, Julia A1 - Kurdyn, Szymon A1 - Schmid, Freia F. A1 - Rücker, Christoph A1 - Mielke, Stephan A1 - Walles, Heike A1 - Hansmann, Jan T1 - A First Vascularized Skin Equivalent as an Alternative to Animal Experimentation JF - ALTEX - Alternatives to Animal Experimentation N2 - Tissue-engineered skin equivalents mimic key aspects of the human skin, and can thus be employed as wound coverage for large skin defects or as in vitro test systems as an alternative to animal models. However, current skin equivalents lack a functional vasculature limiting clinical and research applications. This study demonstrates the generation of a vascularized skin equivalent with a perfused vascular network by combining a biological vascularized scaffold (BioVaSc) based on a decellularized segment of a porcine jejunum and a tailored bioreactor system. Briefly, the BioVaSc was seeded with human fibroblasts, keratinocytes, and human microvascular endothelial cells. After 14 days at the air-liquid interface, hematoxylin & eosin and immunohistological staining revealed a specific histological architecture representative of the human dermis and epidermis including a papillary-like architecture at the dermal-epidermal-junction. The formation of the skin barrier was measured non-destructively using impedance spectroscopy. Additionally, endothelial cells lined the walls of the formed vessels that could be perfused with a physiological volume flow. Due to the presence of a complex in-vivo-like vasculature, the here shown skin equivalent has the potential for skin grafting and represents a sophisticated in vitro model for dermatological research. KW - alternative to animal testing KW - skin equivalents KW - tissue engineering KW - vascularization Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164438 VL - 33 IS - 4 ER -