The presented three different balloon dilation devices for treating Eustachian tube dysfunction were compared regarding their geometries and designs. The balloon dilation behaviour was investigated by an in vitro test setup consisting of a test chamber with 37 °C water, a 2-axis laser scanner and a pressure controller. All balloons could be properly dilated up to the given nominal pressure (NP) or to rated burst pressure (RBP). The balloons reached their expected balloon diameter and length. The compliance data were 1.07 %/atm (TubaVent short), 1.16 %/atm (Acclarent Aera) and 1.28 %/atm (XprESS LoProfile). The measured profile and compliance data can be used for development of new devices for balloon dilation Eustachian tuboplasty.

As suggested by this analysis, patients with MGMT promoter-methylated GBM may benefit from addition of CGT to the standard TMZ treatment, while patients with MGMT promoter-unmethylated GBM may better respond to CGT monotherapy.

e13053 Background: Glioblastoma multiforma (GBM) still has a very poor prognosis even with today’s multimodal combination therapy of resection followed by radio-chemotherapy with temozolomide. Both new molecular inhibitors and immunotherapy may represent future therapeutical tools but due to the variability of the molecular composition in individual GBM, they probably depend on better response prediction. Methods: Based on a close cooperation and logistics between surgery, pathology, laboratory researchers and animal care facilities, we established and analysed cell lines of about 30 primary brain tumors, most of them GBM. Tumors and cell lines were characterised by morphology, growth behaviour, numerous extra- and intracellular antigens, and particularly regarding molecular features. Further, tumors were established in a subcutaneous xenograft mouse model, and growth characteristics were described. These in vitro and in vivo models represent an ideal tool for response analysis of single agent or combined treatment in early cell passages in order to predict response. Besides, relevant antigens and possible shifts of antigen-presentation in tumors can be assessed. Numerous analyses using established and new antitumor compounds – e.g. the integrin inhibitor cilengitide – were performed. Results: We found that although the specific integrin expression is individually different in the tumors analysed, cilengitide sensitivity was similar in most. Addition of temozolomide led to additional, yet not over-additive cytotoxicity. In our panel of GBM specimens we found a very heterogenous pattern of molecular alterations, going along with variations of drug sensitivity. Conclusions: This indicates that, in the future field of individualized approaches, such models are required, in order to enable future strategies to predict the efficacy of immunological, small molecular, biological-based, cytotoxic or other therapeutic strategies. The project was supported by the Förderkreis für krebskranke Kinder Rostock e.V., by a Mecklenburg-Vorpommern graduate scholarship, and by a cooperation with Merck-Serono Research and Development (gift of drug).

A two-step method for investigating the stiffnesses and failure loads of vertebral bodies is presented. It is based on the representation of the spine in a global finite element model of structural elements. A detailed model of two interconnected vertebrae and an intervertebral disc was implemented. Calculations on this model are shown which illustrate the dependencies of structural stiffnesses on vertebral body properties. These structural stiffnesses can then be used to represent the spine in the global model.

Electrospinning is used for producing nonwovens for medical polymer-based implants, such as prosthetic valves or covered scaffolds. In this study, nonwovens for prosthetic venous valves are investigated regarding their morphology and mechanics in physiological medium. Spinning molds were developed based on previous venous valve leaflet designs, 3D printed in different sizes and covered with electrospun nonwovens. Samples were stored in a physiological 0.9% saline at 37°C to investigate the influence of fiber rearrangement and swelling in medium for several weeks. Two different nonwovens of thermoplastic silicone-based polycarbonaturethane (TSPCU) were compared. Tensile test results show that storage in medium has a relevant influence on the mechanical properties. SEM images of TSPCU show substantially increased fiber diameters after 8 days stored in medium. After detaching the valve leaflet nonwovens from the molds, shrinkage of the material of approximately 12% was detected. A suitable valve size could be identified for joining with the stent structure into an interventional prosthetic venous valve. The results demonstrate the influence of storage conditions on the morphological and mechanical properties of electrospun TSPCU nonwovens. For development and dimensioning of venous valve leaflets, this change in mechanical behavior and possible shrinkage of the material has to be considered.