title: The effect of timing of mechanical stimulation on proliferation and differentiation of goat bone marrow stem cells cultured on braided PLGA scaffolds.
abstract: Bone marrow stromal cells (BMSCs) have been shown to proliferate and produce matrix when seeded onto braided poly(L-lactide/glycolide) acid (PLGA) scaffolds. Mechanical stimulation may be applied to stimulate tissue formation during ligament tissue engineering. This study describes for the first time the effect of constant load on BMSCs seeded onto a braided PLGA scaffold. The seeded scaffolds were subjected to four different loading regimes: Scaffolds were unloaded, loaded during seeding, immediately after seeding, or 2 days after seeding. During the first 5 days, changing the mechanical environment seemed to inhibit proliferation, because cells on scaffolds loaded immediately after seeding or after a 2-day delay, contained fewer cells than on unloaded scaffolds or scaffolds loaded during seeding (p<0.01 for scaffolds loaded after 2 days). During this period, differentiation increased with the period of load applied. After day 5, differences in cell content and collagen production leveled off. After day 11, cell number decreased, whereas collagen production continued to increase. Cell number and differentiation at day 23 were independent of the timing of the mechanical stimulation applied. In conclusion, static load applied to BMSCs cultured on PLGA scaffolds allows for proliferation and differentiation, with loading during seeding yielding the most rapid response. Future research should be aimed at elucidating the biomechanical and biochemical characteristics of tissue formed by BMSCs on PLGA under mechanical stimulation.
authors.affiliation: Department of Orthopedics University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Floor
authors.initials: F
authors.lastname: van Eijk
authors.forename: Daniel B F
authors.initials: DB
authors.lastname: Saris
authors.forename: Laura B
authors.initials: LB
authors.lastname: Creemers
authors.forename: Jens
authors.initials: J
authors.lastname: Riesle
authors.forename: W Jaap
authors.initials: WJ
authors.lastname: Willems
authors.forename: Clemens A
authors.initials: CA
authors.lastname: van Blitterswijk
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Verbout
authors.forename: Wouter J A
authors.initials: WJ
authors.lastname: Dhert
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects* / Q000648:ultrastructure; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D006016:Glycolates / Q000494:pharmacology*; D006041:Goats; D006909:Hydroxyproline / Q000378:metabolism; D019344:Lactic Acid; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000648:ultrastructure; D013997:Time Factors; D054457:Tissue Scaffolds
chemical_list: D006016:Glycolates; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen; D004247:DNA; D006909:Hydroxyproline