Engineering of cell-laden gelatin-based microgels for cell delivery and immobilization in regenerative therapies

Issue title: Selected papers of the 36th Conference of the German Society for Clinical Microcirculation and Hemorheology, 5–8. June, 2017, Greifswald, Germany

Guest editors: M. Jünger, A. Krüger-Genge and F. Jung

Article type: Research Article

Authors: Blocki, Anna^{a; b; 1} | Löper, Farina^{b; 1} | Chirico, Nino^a | Neffe, Axel T.^{a; b} | Jung, Friedrich^{a; b} | Stamm, Christof^{b; c} | Lendlein, Andreas^{a; b; *}

Affiliations: [a] Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Teltow, Germany | [b] Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Charité - Universitätsmedizin Berlin and Helmholtz-Zentrum Geesthacht, Teltow, Germany | [c] Deutsches Herzzentrum Berlin (DHZB), Berlin, Germany

Correspondence: [*] Corresponding author: Andreas Lendlein, Institute of Biomaterial Science, Helmholtz-Zentrum Geesthacht, Kantstr. 55, 14513 Teltow, Germany. Tel.: +49 0 3328 352 235; Fax: +49 0 3328 352 452; E-mail: [email protected].

Note: [1] These authors contributed equally to this work.

Abstract: Cell-based therapies often face the challenge of low cell retention and viability upon transplantation. Hence, biomaterials, which can immobilize transplanted cells, while at the same time support cell viability, are essential for successful clinical application. Noteworthy, biomaterials in the micrometer range such as microcapsules or microspheres have the advantage of a minimally invasive introduction into tissue. Hence, we established an approach to generate gelatin-based cell carriers in the form of microspherical hydrogels. Fibroblasts were microencapsulated in glycidylmethacrylate (GMA)-functionalized gelatin by photopolymerization. While the degree of GMA-functionalization was kept constant, the hydrogel cross-linking density was adjusted by varying the time of irradiation or the average gelatin-chain length. Stable microspheres were synthesized from 10 wt% GMA-gelatin solutions for all irradiation periods tested (0.5 –2 min). Evaluation of cell viability revealed that microgels with the same weight content of biopolymer but with decreased cross-linking densities and thus decreased storage and E modulus, resulted in best cell support. Noteworthy, encapsulated cells partially migrated out of the microspheres and attached to the spherical surface. 10 wt% GMA-gelatin-based hydrogels with E moduli comparable to the native cellular niche proved to be a promising biomaterial suitable for the production of cell-laden microspheres and shall be evaluated further for biomedical application.

Keywords: Gelatin, hydrogel, cell encapsulation, microspheres, microgels, microbeads

DOI: 10.3233/CH-179206

Journal: Clinical Hemorheology and Microcirculation, vol. 67, no. 3-4, pp. 251-259, 2017