Cryogels to establish immunotherapeutic organoids

Abstract

Event Abstract Back to Event Cryogels to establish immunotherapeutic organoids Roberta Aliperta1, Petra Welzel2, 3, Marcello Stanzione4, Marc Cartellieri5, Uwe Freudenberg2, 3, Claudia Arndt1, Carsten Werner2, 3, Martin Bornhäuser6, Gerhard Ehninger6 and Michael Bachmann1, 3, 7 1 Helmholtz-Zentrum Dresden-Rossendorf, Department of Radioimmunology, Institute of Radiopharmaceutical Cancer Research, Germany 2 Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials Dresden, Germany 3 Technische Universität Dresden, Center for Regenerative Therapies Dresden, Germany 4 Technische Universität Dresden, Institute of Physiological Chemistry, Germany 5 Cellex Patient Treatment GmbH, Germany 6 University Hospital 'Carl Gustav Carus', Technische Universität Dresden, Medical Clinic and Polyclinic I, Germany 7 Technische Universität Dresden, University Cancer Center (UCC), Tumorimmunology, Germany Introduction: T-cell based immunotherapy of tumors has gained much prominence in the last years. In this context treatments relying on the administration of recombinant bispecific antibodies (bsAbs) for retargeting effector T-lymphocytes towards cancer cells are of particular interest[1],[2]. However, several challenges with respect to pharmacokinetics, efficiency and safety need to be overcome. Our aim is to develop, test and apply a transplantable cell/biomaterial-based bsAb production platform (immunotherapeutic organoid) ensuring customized sustained release and effective and persistent levels of these T-cell stimulating therapeutic proteins over time with low risk of side effects. Materials and Methods: Macroporous biohybrid hydrogel matrices (cryogels) were prepared by combining hydrogel network formation via chemical cross-linking of four-arm poly(ethylene glycol) (starPEG) and heparin with the cryogelation technology[3]. The capability of these starPEG-heparin cryogel materials to support the ingrowth, attachment, distribution and proliferation of gene-modified mesenchymal stem cells (MSCs) in vitro was tested by immunostaining/fluorescence microscopy and by using metabolic activity assays. Cell migration experiments were used to verify the attachment between the MSCs and the functionalized biomaterial under various experimental conditions. The production of therapeutic antibodies by the cell/cryogel machinery and their potential to kill tumor cells was quantified by enzyme-linked immunosorbent assays (ELISAs) at different time points and standard T-cell mediated cytotoxicity assays. Results and Discussion: The unique sponge-like structure of the starPEG-heparin cryogel material with interconnected macropores provides a high surface-to-volume ratio and enabled ingrowth, proliferation and viability of gene-modified bsAb-releasing-MSCs and effective transport of nutrients, metabolites and therapeutic antibodies. Functionalization of the gels with peptide sequences allowed for integrin-mediated adhesion of the modified MSCs. The established cell/cryogel machinery was proved to be feasible for maintaining MSCs in a supporting microenvironment, and for producing recombinant bsAbs for prolonged time spans resulting in specific T-cell mediated tumor cell killing. Conclusion: The proposed cell/cryogel system is a suitable candidate for developing transplantable immunotherapeutic organoids for future in vivo applications. It ensures the constant delivery of bsAbs to promote customized T-cell activation and efficient killing of tumor cells and paves the way to a safer and more effective tumor-specific strategy for T-cell mediated cancer treatment.