title: Effects of in vitro chondrogenic priming time of bone-marrow-derived mesenchymal stromal cells on in vivo endochondral bone formation.
abstract: Recapitulation of endochondral ossification leads to a new concept of bone tissue engineering via a cartilage intermediate as an osteoinductive template. In this study, we aimed to investigate the influence of in vitro chondrogenic priming time for the creation of cartilage template on the in vivo endochondral bone formation both qualitatively and quantitatively. To this end, rat bone-marrow-derived mesenchymal stromal cells (MSCs) were seeded onto two scaffolds with distinguished features: a fibrous poly(lactic-co-glycolic acid)/poly(ε-caprolactone) electrospun scaffold (PLGA/PCL) and a porous hydroxyapatite/tricalcium phosphate composite (HA/TCP). The constructs were then chondrogenically differentiated for 2, 3 and 4 weeks in vitro, followed by subcutaneous implantation in vivo for up to 8 weeks. A longer chondrogenic priming time resulted in a significantly increased amount and homogeneous deposition of the cartilage matrix on both the PLGA/PCL and HA/TCP scaffolds in vitro. In vivo, all implanted constructs gave rise to endochondral bone formation, whereas the bone volume was not affected by the length of priming time. An unpolarized woven bone-like structure, with significant amounts of cartilage remaining, was generated in fibrous PLGA/PCL scaffolds, while porous HA/TCP scaffolds supported progressive lamellar-like bone formation with mature bone marrow development. These data suggest that, by utilizing a chondrogenically differentiated MSC-scaffold construct as cartilage template, 2 weeks of in vitro priming time is sufficient to generate a substantial amount of vascularized endochondral bone in vivo. The structure of the bone depends on the chemical and structural cues provided by the scaffold design.
authors.affiliation: Department of Biomaterials, Radboud University Medical Center, Dentistry 309, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands; The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Wanxun
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Biomaterials, Radboud University Medical Center, Dentistry 309, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: Sanne K
authors.initials: SK
authors.lastname: Both
authors.affiliation: Department of Orthopaedics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands; Department of Otorhinolaryngology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: Gerjo J V M
authors.initials: GJ
authors.lastname: van Osch
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Yining
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Biomaterials, Radboud University Medical Center, Dentistry 309, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
authors.affiliation: Department of Biomaterials, Radboud University Medical Center, Dentistry 309, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: fang.yang@radboudumc.nl.
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D020219:Chondrogenesis; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis; D011091:Polyesters / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D011916:Rats, Inbred F344; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D011091:Polyesters; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C016240:polycaprolactone; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Bone regeneration; Chondrogenic priming; Endochondral bone formation; Mesenchymal stromal cells; Scaffold