title: Multiscale three-dimensional scaffolds for soft tissue engineering via multimodal electrospinning.
abstract: A novel (scalable) electrospinning process was developed to fabricate bio-inspired multiscale three-dimensional scaffolds endowed with a controlled multimodal distribution of fiber diameters and geared towards soft tissue engineering. The resulting materials finely mingle nano- and microscale fibers together, rather than simply juxtaposing them, as is commonly found in the literature. A detailed proof of concept study was conducted on a simpler bimodal poly(epsilon-caprolactone) (PCL) scaffold with modes of fiber distribution at 600 nm and 3.3 microm. Three conventional unimodal scaffolds with mean diameters of 300 nm and 2.6 and 5.2 microm, respectively, were used as controls to evaluate the new materials. Characterization of the microstructure (i.e. porosity, fiber distribution and pore structure) and mechanical properties (i.e. stiffness, strength and failure mode) indicated that the multimodal scaffold had superior mechanical properties (Young's modulus approximately 40MPa and strength approximately 1MPa) in comparison with the controls, despite the large porosity ( approximately 90% on average). A biological assessment was conducted with bone marrow stromal cell type (mesenchymal stem cells, mTERT-MSCs). While the new material compared favorably with the controls with respect to cell viability (on the outer surface), it outperformed them in terms of cell colonization within the scaffold. The latter result, which could neither be practically achieved in the controls nor expected based on current models of pore size distribution, demonstrated the greater openness of the pore structure of the bimodal material, which remarkably did not come at the expense of its mechanical properties. Furthermore, nanofibers were seen to form a nanoweb bridging across neighboring microfibers, which boosted cell motility and survival. Lastly, standard adipogenic and osteogenic differentiation tests served to demonstrate that the new scaffold did not hinder the multilineage potential of stem cells.
authors.affiliation: NAST Centre and Department of Chemical Science and Technology, University of Rome Tor Vergata, 00133 Rome, Italy.
authors.forename: Sherif
authors.initials: S
authors.lastname: Soliman
authors.forename: Stefania
authors.initials: S
authors.lastname: Pagliari
authors.forename: Antonio
authors.initials: A
authors.lastname: Rinaldi
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Forte
authors.forename: Roberta
authors.initials: R
authors.lastname: Fiaccavento
authors.forename: Francesca
authors.initials: F
authors.lastname: Pagliari
authors.forename: Ornella
authors.initials: O
authors.lastname: Franzese
authors.forename: Marilena
authors.initials: M
authors.lastname: Minieri
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Nardo
authors.forename: Silvia
authors.initials: S
authors.lastname: Licoccia
authors.forename: Enrico
authors.initials: E
authors.lastname: Traversa
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004058:Diffusion / Q000187:drug effects; D005260:Female; D005455:Fluorescent Antibody Technique; D008422:Materials Testing; D055595:Mechanical Phenomena / Q000187:drug effects; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000494:pharmacology; D016062:Porosity / Q000187:drug effects; D015203:Reproducibility of Results; D019098:Telomerase / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D019098:Telomerase; C509187:Tert protein, mouse