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Author: Wegener, Michael × Author: 069f3759-a75c-4ce8-960d-adcab6372d79 ×

Publications Search Results

Now showing 1 - 7 of 7
  • Publication
    Biocompatible elastomers for 3D biomaterials by additive manufacturing
    ( 2013)
    Borchers, Kirsten
    ;
    Bierwisch, Claas
    ;
    Engelhardt, Sascha
    ;
    Graf, Careen
    ;
    Hoch, Eva
    ;
    Jaeger, Raimund
    ;
    Kluger, Petra Juliane
    ;
    Krüger, Hartmut
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Novosel, Esther
    ;
    Refle, Oliver
    ;
    Schuh, Christian
    ;
    Seiler, Nadine
    ;
    Tovar, Günter E.M.
    ;
    Wegener, Michael
    ;
    Ziegler, Tobias
    The future vision of implants comprises individually tailored prostheses and the generation of artificial tissue and organs generated from the patient's own cells. In order to develop artificial, biomimetic structures which perform as well as natural ones, we need fabrication processes that do not set any limits to the generation of shapes, and materials that allow for tailoring of their physical, chemical, and biological properties. We introduce new biocompatible materials for the manufacturing of flexible structures by freeform fabrication.
  • Patent
    Device for producing three-dimensional structures in layers, comprises a print head assembly, a radiation source assembly, and a heat source, where the print head assembly is positioned in a controlled manner relative to a working plane
    ( 2012)
    Jaeger, Raimund
    ;
    Graf, Careen
    ;
    Kluger, Petra
    ;
    Riester, Dominik
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Bierwisch, Claas
    ;
    Tovar, Günter E.M.
    ;
    Engelhardt, Sascha
    ;
    Refle, Oliver
    ;
    Borchers, Kirsten
    ;
    Seiler, Nadine
    ;
    Krüger, Hartmut
    ;
    Bremus-Koebberling, Elke A.
    ;
    Wegener, Michael
    The device comprises a print head assembly (1), a radiation source assembly, and a heat source controllable by a control unit acting on a thermal photolinkable material layer separated on a working plane (E). The print head assembly is positioned in a controlled manner relative to a working plane, and is connected to two reservoir containers (2, 3, 4) in which liquid to paste-like photolinkable materials each having a different photosensitivity level are stored. The respective material is delivered via the print head assembly to the selected locations in the region of the working plane. The device comprises a print head assembly (1), a radiation source assembly, and a heat source controllable by a control unit acting on a thermal photolinkable material layer separated on a working plane (E). The print head assembly is positioned in a controlled manner relative to the working plane, and is connected to two reservoir containers (2, 3, 4) in which liquid to paste-like photolinkable materials each having a different photosensitivity level are stored. The respective material is delivered via the print head assembly to the selected locations in the region of the working plane. The radiation source assembly emits electromagnetic radiation in an areal manner depending upon the photosensitivity of the photolinkable material that is delivered to selected locations on the working plane. The radiation source assembly comprises a laser light source (L) as a single radiation source whose laser beam is focused with the aid of an optical unit for beam deflection- and focusing into a region of the photolinkable material layer, which is delivered in an areal manner onto the working plane by the print head assembly, and initiates two-photon or multi-photon processes in the focus region within the photolinkable material layer. The two-photon or multi-photon processes lead to the solidification of the photolinkable material in the selected locations. The radiation source assembly comprises a first radiation source irradiating in the areal manner onto the working plane. The first radiation source: emits an electromagnetic radiation having a first wavelength or a first wavelength spectrum, which differs from the wavelength of the laser beam; and comprises a LED or diode array or an other light source having limited spectral regions. The optical unit producing a widening laser beam is present in the device by which a laser beam cross-section is expandable to a flat illumination of the photolinkable material that is delivered to the selected locations on the working plane. An optical switching element is provided that supplies laser beam either the unit for beam deflection- and focusing or the laser beam. The optical unit reducing a light intensity of the widening laser beam is introduced in an optical path of the laser beam. The print head assembly: is formed for discharging the photolinkable materials such that the photolinkable material is delivered on the working plane under formation of a flat layer with a uniform layer thickness and a flat surface layer; and comprises pressure nozzles (5, 6) arranged along a line by which the photolinkable material is uniformly delivered. A non-contact working measuring system is provided that detects the layer thickness and/or a layer surface quality of the photolinkable material layer deposited on the working plane. A control unit is provided that controls on the basis of a target/actual-comparison of the print head assembly in a trap of faulty layer thickness and/or the layer surface quality to corrective measures. The photolinkable material is stored in an other photolinkable structure material, an other reservoir unit, and a support material. The support- and the photolinkable structure material are delivered via two different pressure nozzles of the printhead assembly to the selected locations on the respective material of the common working plane. The photolinkable material is stockpiled in the other reservoir unit by which the printhead assembly is delivered in an other working plane. A single piece pipe system has pipe diameters and pipe lengths of 5 mm and 0.1 mu m respectively. The pipe system: has a porous pipe wall having a porous diameter of 0.5-10 mu m and elastic properties, which correspond to the elastic properties of a biological tissue; and consists of biologically compatible material, or is functionalized with a biocompatible material surface. An independent claim is included for a method for producing three-dimensional structures in layers.
  • Patent
    Producing two/three-dimensional structure, by applying photo-crosslinkable material having crosslinking component on substrate, and fixing photo-crosslinkable material by radiation, where crosslinking component includes e.g. acrylate
    ( 2012)
    Krüger, Hartmut
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Wegener, Michael
    ;
    Graf, Careen
    ;
    Refle, Oliver
    ;
    Bremus-Koebberling, Elke
    ;
    Engelhardt, Sascha
    ;
    Schuh, Christian
    ;
    Dettling, Melanie
    ;
    Novosel, Esther
    ;
    Borchers, Kirsten
    ;
    Tovar, Günter E.M.
    The method comprises applying a photo-crosslinkable material on a substrate, and fixing the photo-crosslinkable material by an electromagnetic radiation. A part of the photo-crosslinkable group is not implemented into the step of fixing the photo-crosslinkable material by the electromagnetic radiation. An unreacted photo-crosslinkable or an other non-photo-crosslinkable functional group and the photo-crosslinkable or photo-crosslinked material are functionalized with a biofunctional component. The biofunctional component is indirectly connected via a nanoparticle. The method comprises applying a photo-crosslinkable material on a substrate, and fixing the photo-crosslinkable material by an electromagnetic radiation. A part of the photo-crosslinkable group is not implemented into the step of fixing the photo-crosslinkable material by the electromagnetic radiation. An unreacted photo-crosslinkable or an other non photo-crosslinkable functional group and the photo-crosslinkable or photo-crosslinked material are functionalized with a biofunctional component. The biofunctional component is indirectly connected via a nanoparticle having the photo-crosslinkable or the photo-crosslinked material, where the polymeric crosslinking component is introduced in an amount of 5-30 mass%, and the photoinitiator component is introduced in an amount of 0.5-1%. An independent claim is included for two- or three-dimensional structure.
  • Publication
    Materials and manufacturing technology for the fabrication of bioinspired artifical vascular systems
    ( 2012)
    Borchers, Kirsten
    ;
    Bierwisch, Claas
    ;
    Engelhard, Sascha
    ;
    Graf, Careen
    ;
    Jaeger, Raimund
    ;
    Kluger, Petra
    ;
    Krüger, Hartmut
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Novosel, Esther
    ;
    Refle, Oliver
    ;
    Schuh, Christian
    ;
    Seiler, Nadine
    ;
    Tovar, Günter E.M.
    ;
    Wegener, Michael
    ;
    Ziegler, Tobias
    The key technology for in 3-D vitro engineered tissues is the establishment of vascular scaffolds. Today it is not yet possible to generate vascular structures resembling the typical organisation of mature blood vessels in vivo. In the past, significant progress has been made mainly in the development of tissue-like engineered products that are not dependent on a significant Ievel of vascular support, such as bioartificial cartilage and skin equivalents. The generation of adequate tissue substitutes of most other types of tissues require a functional vascular network for the supply of nutrients and the disposal of metabolites throughout a functional and growing tissue. Therefore, the generation of vascularised artificial tissues defines a challenging topic for future developments.
  • Publication
    Material- und Prozessentwicklung für die Herstellung kleinlumiger, verzweigter Gefäßsysteme mittels Inkjetdruck und Zweiphotonenpolymerisation
    ( 2011)
    Borchers, Kirsten
    ;
    Bierwisch, Claas
    ;
    Engelhardt, Sascha
    ;
    Graf, Careen
    ;
    Hirth, Thomas
    ;
    Hoch, Eva
    ;
    Jaeger, Raimund
    ;
    Kluger, Petra
    ;
    Krüger, Hartmut
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Novosel, Esther
    ;
    Refle, Oliver
    ;
    Schuh, Christian
    ;
    Seiler, Nadine
    ;
    Tovar, Günter E.M.
    ;
    Wegener, Michael
    ;
    Ziegler, Tobias
    Kontrolle mikroskopischer und makroskopischer Eigenschaften erlangen bei der Entwicklung funktionaler Biomaterialien immer stärkere Wichtigkeit. Um Strukturgrößen von wenigen Mikrometern bis in den Zentimeterbereich zu generieren, kombinieren wir 3D-Inkjet Technik mit hochauflösender Multiphotonenpolymerisation (MPP).
  • Publication
    Generation of small diameter, branched vascular systems by a combination of inkjet printing and multiphoton polymerization
    ( 2011)
    Kluger, Petra Juliane
    ;
    Borchers, Kirsten
    ;
    Refle, Oliver
    ;
    Engelhard, Sascha
    ;
    Meyer, Wolfdietrich orcid-logo
    ;
    Novosel, Esther
    ;
    Graf, Careen
    ;
    Bierwisch, Claas
    ;
    Schuh, Christian
    ;
    Seiler, Nadine
    ;
    Wegener, Michael
    ;
    Krüger, Hartmut
    ;
    Jaeger, Raimund
    ;
    Hirth, Thomas
    ;
    Gillner, Arnold
    ;
    Tovar, Günter E.M.
    Introduction: To date only single in vitro engineered tissues are transferred to clinical approaches due to todays inability to fabricate suitable, artifical vascular systems. Combining inkjet printing with high-resolution multiphoton polymerization (MPP) enables us to generate branched, tubular systems with diameters << 1 mm. New synthetic polymers were tailored to match the needs of the technical building process and the elastic properties of blood vessels. The polymers were biofunctionalized to achieve a close coating with endothelial cells (ECs). Experimental Methods: Based on numerical simulations, branched tubular scaffolds were fabricated by combining inkjet printing and MPP. Precursor polymers, cross linking agent, photo initiators and solvent additives were optimized to yield photo reactive inks with customizd E-moduli. Crosslinked polymers were modified with derivatized heparin and RGD and analyzed by XPS and colorimetric methods. Viability, proliferation, functionality of primary human microvascular ECs on the substrates was determined, using several assays and immunocytological stainings. Results: A set-up for integrating inkjet printing and MPP has been designed with which branched vessel scaffolds have been fabricated. The diameter of the tubes can range between 20 µm and several millimeters. Material compositions have been developed to achieve E-Moduli of 2-2000 MPa after crosslinking, the lower are similar to natural blood vessels. Suitable aftertreatment ensured biocompatibility of the processed polymers, thereafter thio-heparin and RGD have been covalently bound on the surface. On these biofunctionalized substrates an increased adhesion, viability and proliferation of ECs has been determined in comparison with unmodified substrates. EC-typical antigene expression has been observed by immunocytological stainings on all substrates. Conclusion: The presented combination of rapid prototyping techniques makes it possible to generate small diameter vessel-like systems that can be applied for supplying in vitro engineered tissues in a larger scale.