title: Mechanical Actuation Systems for the Phenotype Commitment of Stem Cell-Based Tendon and Ligament Tissue Substitutes.
abstract: High tensile forces transmitted by tendons and ligaments make them susceptible to tearing or complete rupture. The present standard reparative technique is the surgical implantation of auto- or allografts, which often undergo failure.Currently, different cell types and biomaterials are used to design tissue engineered substitutes. Mechanical stimulation driven by dedicated devices can precondition these constructs to a remarkable degree, mimicking the local in vivo environment. A large number of dynamic culture instruments have been developed and many appealing results collected. Of the cells that have been used, tendon stem cells are the most promising for a reliable stretch-induced tenogenesis, but their reduced availability represents a serious limitation to upscaled production. Biomaterials used for scaffold fabrication include both biological molecules and synthetic polymers, the latter being improved by nanotechnologies which reproduce the architecture of native tendons. In addition to cell type and scaffold material, other variables which must be defined in mechanostimulation protocols are the amplitude, frequency, duration and direction of the applied strain. The ideal conditions seem to be those producing intermittent tension rather than continuous loading. In any case, all physical parameters must be adapted to the specific response of the cells used and the tensile properties of the scaffold. Tendon/ligament grafts in animals usually have the advantage of mechanical preconditioning, especially when uniaxial cyclic forces are applied to cells engineered into natural or decellularized scaffolds. However, due to the scarcity of in vivo research, standard protocols still need to be defined for clinical applications.
authors.affiliation: BioEngLab, Health Science and Technology - Interdepartmental Center for Industrial Research (HST-CIRI), University of Bologna, Ozzano Emilia, BO, Italy.|Prometeo Laboratory - Department of Research, Innovation and Technology (RIT), The Rizzoli Orthopedic Institute, Via di Barbiano 1/10, 40136, Bologna, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Govoni
authors.affiliation: BioEngLab, Health Science and Technology - Interdepartmental Center for Industrial Research (HST-CIRI), University of Bologna, Ozzano Emilia, BO, Italy.|Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, BO, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Muscari
authors.affiliation: Laboratory of Cellular and Molecular Engineering "Silvio Cavalcanti" - Department of Electrical, Electronic and Information Engineering (DEI), University of Bologna, Via Venezia, 52, I-47521, Cesena, FC, Italy.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lovecchio
authors.affiliation: BioEngLab, Health Science and Technology - Interdepartmental Center for Industrial Research (HST-CIRI), University of Bologna, Ozzano Emilia, BO, Italy.|Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Bologna, BO, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Guarnieri
authors.affiliation: BioEngLab, Health Science and Technology - Interdepartmental Center for Industrial Research (HST-CIRI), University of Bologna, Ozzano Emilia, BO, Italy. emanuele.giordano@unibo.it.|Laboratory of Cellular and Molecular Engineering "Silvio Cavalcanti" - Department of Electrical, Electronic and Information Engineering (DEI), University of Bologna, Via Venezia, 52, I-47521, Cesena, FC, Italy. emanuele.giordano@unibo.it.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Giordano
mesh_terms: D000818:Animals; D006801:Humans; D008022:Ligaments / Q000166:cytology*; D010641:Phenotype; D013234:Stem Cells / Q000166:cytology*; D013314:Stress, Mechanical; D013710:Tendons / Q000166:cytology*; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds
keywords: Ligament; Mechanical actuation systems; Regenerative medicine; Stem cells; Tendon; Tissue engineering