@article{EngelMicheelHanack2022, author = {Engel, Robert and Micheel, Burkhard and Hanack, Katja}, title = {Three-dimensional cell culture approach for in vitro immunization and the production of monoclonal antibodies}, series = {Biomedical materials : materials for tissue engineering and regenerative medicine}, volume = {17}, journal = {Biomedical materials : materials for tissue engineering and regenerative medicine}, number = {5}, publisher = {Inst. of Physics}, address = {London}, issn = {1748-6041}, doi = {10.1088/1748-605X/ac7b00}, pages = {11}, year = {2022}, abstract = {The generation of monoclonal antibodies using an in vitro immunization approach is a promising alternative to conventional hybridoma technology. As recently published, the in vitro approach enables an antigen-specific activation of B lymphocytes within 10-12 d followed by immortalization and subsequent selection of hybridomas. This in vitro process can be further improved by using a three-dimensional surrounding to stabilize the complex microenvironment required for a successful immune reaction. In this study, the suitability of Geltrex as a material for the generation of monoclonal antigen-specific antibodies by in vitro immunization was analyzed. We could show that dendritic cells, B cells, and T cells were able to travel through and interact inside of the matrix, leading to the antigen-specific activation of T and B cells. For cell recovery and subsequent hybridoma technique the suitability of dispase and Corning cell recovery solution (CRS) was compared. In our experiments, the use of dispase resulted in a severe alteration of cell surface receptor expression patterns and significantly higher cell death, while we could not detect an adverse effect of Corning CRS. Finally, an easy approach for high-density cell culture was established by printing an alginate ring inside a cell culture vessel. The ring was filled with Geltrex, cells, and medium to ensure a sufficient supply during cultivation. Using this approach, we were able to generate monoclonal hybridomas that produce antigen-specific antibodies against ovalbumin and the SARS-CoV-2 nucleocapsid protein.}, language = {en} } @article{BhuvaneshSaretiaRochetal.2017, author = {Bhuvanesh, Thanga and Saretia, Shivam and Roch, Toralf and Sch{\"o}ne, Anne-Christin and Rottke, Falko O. and Kratz, Karl and Wang, Weiwei and Ma, Nan and Schulz, Burkhard and Lendlein, Andreas}, title = {Langmuir-Schaefer films of fibronectin as designed biointerfaces for culturing stem cells}, series = {Polymers for advanced technologies}, volume = {28}, journal = {Polymers for advanced technologies}, publisher = {Wiley}, address = {Hoboken}, issn = {1042-7147}, doi = {10.1002/pat.3910}, pages = {1305 -- 1311}, year = {2017}, abstract = {Glycoproteins adsorbing on an implant upon contact with body fluids can affect the biological response in vitro and in vivo, depending on the type and conformation of the adsorbed biomacromolecules. However, this process is poorly characterized and so far not controllable. Here, protein monolayers of high molecular cohesion with defined density are transferred onto polymeric substrates by the Langmuir-Schaefer (LS) technique and were compared with solution deposition (SO) method. It is hypothesized that on polydimethylsiloxane (PDMS), a substrate with poor cell adhesion capacity, the fibronectin (FN) layers generated by the LS and SO methods will differ in their organization, subsequently facilitating differential stem cell adhesion behavior. Indeed, atomic force microscopy visualization and immunofluorescence images indicated that organization of the FN layer immobilized on PDMS was uniform and homogeneous. In contrast, FN deposited by SO method was rather heterogeneous with appearance of structures resembling protein aggregates. Human mesenchymal stem cells showed reduced absolute numbers of adherent cells, and the vinculin expression seemed to be higher and more homogenously distributed after seeding on PDMS equipped with FN by LS in comparison with PDMS equipped with FN by SO. These divergent responses could be attributed to differences in the availability of adhesion molecule ligands such as the Arg-Gly-Asp (RGD) peptide sequence presented at the interface. The LS method allows to control the protein layer characteristics, including the thickness and the protein orientation or conformation, which can be harnessed to direct stem cell responses to defined outcomes, including migration and differentiation. Copyright (c) 2016 John Wiley \& Sons, Ltd.}, language = {en} }