abstract
The popularity of cell-laden injectable hydrogels has steeply increased due to their compatibility with minimally invasive surgical procedures. However, the diffusion of indispensable molecules for cell survival through bulk hydrogel structures, particularly oxygen, is often limited to micrometric distances, often hampering cell viability or uniform tissue formation in constructs with clinically relevant sizes. The introduction of micropores in hydrogels or the use of oxygen-generating materials has enabled combining advantages of porous 3D scaffolds with the injectability properties of in situ-solidifying hydrogels. Here, cell-laden injectable gelatin methacryloyl (GelMA) foams are fabricated using a single polymer formulation. Air bubbles are introduced into GelMA solutions using a simple-to-implement method based on pulling/pushing the solution through a syringe. Human mesenchymal stem cells derived from the adipose tissue (hASCs) cultured in bulk hydrogels (diameter c.a. 5 mm) show low permanence in the core of the materials and stain for factors associated to hypoxia (hypoxia-inducible factor-1 alpha (HIF-1 alpha)) after 7 days of culture. In opposition, cells cultured in optimized foams do not stain for HIF-1 alpha, show high permanence, homogeneous viability, and consistent phenotype in the whole depth of the biomaterials, while secreting increased amounts of regenerative growth factors to the surrounding medium.
keywords
CHITOSAN SCAFFOLDS; STEM-CELLS; TISSUE; POROSITY; DEXAMETHASONE; SIZE
subject category
Engineering; Science & Technology - Other Topics; Materials Science
authors
Salvador, T; Oliveira, MB; Mano, JF
our authors
João Mano
Vice Director
Mariana Braga de Oliveira
Assistant Researcheracknowledgements
This work was supported by the POCI in the component FEDER and by national funds (OE) through FCT/MCTES, in the scope of the projects TranSphera (PTDC/BTM-ORG/30770/2017). This work was also devel-oped within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. M.B.O. acknowledges the individual contract CEECIND/03605/2017.