Coaxial electrospinning of PEEU/gelatin to fiber meshes with enhanced mesenchymal stem cell attachment and proliferation

Issue title: Selected post-conference papers of the 38th Conference of the German Society for Clinical Microcirculation and Hemorheology, 21-23 November 2019, Braunschweig, Germany

Guest editors: P. Wiggermann, A. Krüger-Genge and F. Jung

Article type: Research Article

Authors: Tung, Wing Tai^{a; b} | Zou, Jie^a | Sun, Xianlei^{a; b} | Wang, Weiwei^a | Gould, Oliver E.C.^a | Kratz, Karl^a | Ma, Nan^{a; c; *} | Lendlein, Andreas^{a; b; c; *}

Affiliations: [a] Institute of Biomaterial Science and Berlin-Brandenburg Centre for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany | [b] University of Potsdam, Potsdam, Germany | [c] Institute of Chemistry and Biochemistry, Free University of Berlin, Berlin, Germany

Correspondence: [*] Corresponding authors: Nan Ma. E-mail: [email protected] and Andreas Lendlein. E-mail: [email protected].

Abstract: Microfibers with a core-shell structure can be produced by co-axial electrospinning, allowing for the functionalization of the outer layer with bioactive molecules. In this study, a thermoplastic, degradable polyesteretherurethane (PEEU), consisting of poly(p-dioxanone) (PPDO) and poly(ɛ-caprolactone) (PCL) segments with different PPDO to PCL weight ratios, were processed into fiber meshes by co-axial electrospinning with gelatin. The prepared PEEU fibers have a diameter of 1.3±0.5 μm and an elastic modulus of around 5.1±1.0 MPa as measured by tensile testing in a dry state at 37°C, while the PEEU/Gelatin core-shell fibers with a gelatin content of 12±6 wt% and a diameter of 1.5±0.5 μm possess an elastic modulus of 15.0±1.1 MPa in a dry state at 37 °C but as low as 0.7±0.7 MPa when hydrated at 37 °C. Co-axial electrospinning allowed for the homogeneous distribution of the gelatin shell along the whole microfiber. Gelatin with conjugated Fluorescein (FITC) remained stable on the PEEU fibers after 7 days incubation in Phosphate-buffered saline (PBS) at 37 °C. The gelatin coating on PEEU fibers lead to enhanced human adipose tissue derived mesenchymal stem cell (hADSC) attachment and a proliferation rate 81.7±34.1 % higher in cell number in PEEU50/Gelatin fibers after 7 days of cell culture when compared to PEEU fibers without coating. In this work, we demonstrate that water-soluble gelatin can be incorporated as the outer shell of a polymer fiber via molecular entanglement, with a sustained presence and role in enhancing stem cell attachment and proliferation.

Keywords: PEEU, gelatin, electrospun fibers, mesenchymal stem cells, biomaterials

DOI: 10.3233/CH-199235

Journal: Clinical Hemorheology and Microcirculation, vol. 74, no. 1, pp. 53-66, 2020