Polyhydroxyalkanoates Fibrous Scaffolds for Support of Mesenchymal Stem cells

Following a biorefinery approach, it was shown recently to be possible to use the crude glycerol generated during biodiesel production for the biological synthesis of polyhydroxyalkanoates (PHAs) [1, 2]. Human Mesenchymal Stem Cells (hMSC) provide an interesting model of regenerating cells, since they have the ability to differentiate into different cell lines, including the osteo-, chrondro-, adipo- and myogenic lineages. Additionally, these cells have modulatory properties which can be explored for cell therapies targeting immunologic diseases. Electrospun fiber meshes offer tunable mechanical and physical properties that can mimic the structure of the native extracellular matrix, the natural environment where cells inhabit. This integrated study shows that waste glycerol can be biovalorized by the fabrication of electrospun cell biocompatible scaffolds, able to support hMSC ex-vivo cultivation, at acceptable proliferation levels, offering a considerable potential for use in regenerative medicine. The P(3HB-4HB-3HV) terpolymers, one containing 11.4 % 4HB and 3.5% 3HV and the other containing 35.6 % 4HB and 3.4 % 3HV, were electrospun into fibers of average diameters of 600 and 1400 nm, respectively. hMSC were cultured for 7 days in both fiber meshes, showing their ability to support stem cell growth. Comparative results clearly demonstrate that scaffold topology is critical, with electrospun PHA fibers succeeding on the support of significant cell adhesion and proliferation, where planar PHA films failed.