Healing of a Large Long-Bone Defect through Serum-Free In Vitro Priming of Human Periosteum-Derived Cells

• Published in: Stem cell reports Vol. 8; no. 3; pp. 758 - 772
• Main Authors: Bolander, Johanna, Ji, Wei, Leijten, Jeroen, Teixeira, Liliana Moreira, Bloemen, Veerle, Lambrechts, Dennis, Chaklader, Malay, Luyten, Frank P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.03.2017; Elsevier
• Subjects: Animals; Antigens, CD34 - metabolism; Biomarkers; Bone Morphogenetic Protein 2 - genetics; Bone Morphogenetic Protein 2 - metabolism; bone morphogenetic proteins; Bone Regeneration; Cell Differentiation; cell-based constructs; Chondrogenesis - genetics; critical bone fractures; Disease Models, Animal; fracture healing; fracture nonunion regenerative medicine; Fractures, Bone - metabolism; Fractures, Bone - pathology; Fractures, Bone - therapy; Humans; Mice; Mice, Knockout; Osteogenesis - genetics; Periosteum - cytology; progenitor cells; Protein Aggregates; serum free; Signal Transduction; Stem Cell Transplantation; stem cells; Stem Cells - cytology; Stem Cells - metabolism; Wound Healing; stem cells; critical bone fractures; cell-based constructs; fracture nonunion regenerative medicine; progenitor cells; serum free; fracture healing; bone morphogenetic proteins
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2017.01.005

Clinical translation of cell-based strategies for regenerative medicine demands predictable in vivo performance where the use of sera during in vitro preparation inherently limits the efficacy and reproducibility. Here, we present a bioinspired approach by serum-free pre-conditioning of human periosteum-derived cells, followed by their assembly into microaggregates simultaneously primed with bone morphogenetic protein 2 (BMP-2). Pre-conditioning resulted in a more potent progenitor cell population, while aggregation induced osteochondrogenic differentiation, further enhanced by BMP-2 stimulation. Ectopic implantation displayed a cascade of events that closely resembled the natural endochondral process resulting in bone ossicle formation. Assessment in a critical size long-bone defect in immunodeficient mice demonstrated successful bridging of the defect within 4 weeks, with active contribution of the implanted cells. In short, the presented serum-free process represents a biomimetic strategy, resulting in a cartilage tissue intermediate that, upon implantation, robustly leads to the healing of a large long-bone defect. [Display omitted] •Serum-free pre-conditioning affects the identity of periosteal progenitor cells•A reduced CD105+, elevated CD34+, and upregulated BMP receptor expression was seen•Priming by aggregation and BMP stimulation induced endochondral bone formation•Validation in a critical size fracture model confirmed endochondral healing The use of sera in the preparation of cell-based strategies critically limits the efficacy and reproducibility of the process as it conflicts with cellular responses. Luyten and colleagues present a bioinspired engineering process including serum-free pre-conditioning combined with micro-aggregation and bone morphogenetic protein priming resulting in a self-sustained tissue intermediate that, upon implantation, successfully heals critical long-bone defects.