title: Effects of cell-attachment and extracellular matrix on bone formation in vivo in collagen-hydroxyapatite scaffolds.
abstract: Cell-based tissue engineering can be used to replace missing or damaged bone, but the optimal methods for delivering therapeutic cells to a bony defect have not yet been established. Using transgenic reporter cells as a donor source, two different collagen-hydroxyapatite (HA) scaffolds, and a critical-size calvarial defect model, we investigated the effect of a cell-attachment period prior to implantation, with or without an extracellular matrix-based seeding suspension, on cell engraftment and osteogenesis. When quantitatively compared, the in-house scaffold implanted immediately had a higher mean radiopacity than in-house scaffolds incubated overnight. Both scaffold types implanted immediately had significantly higher area fractions of donor cells, while the in-house collagen-HA scaffolds implanted immediately had higher area fractions of the mineralization label compared with groups incubated overnight. When the cell loading was compared in vitro for each delivery method using the in-house scaffold, immediate loading led to higher numbers of delivered cells. Immediate loading may be preferable in order to ensure robust bone formation in vivo. The use of a secondary ECM carrier improved the distribution of donor cells only when a pre-attachment period was applied. These results have improved our understanding of cell delivery to bony defects in the context of in vivo outcomes.
authors.affiliation: Department of Materials Science & Engineering, University of Connecticut, Storrs, Connecticut, United States of America.
authors.forename: Max M
authors.initials: MM
authors.lastname: Villa
authors.affiliation: Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut, United States of America.
authors.forename: Liping
authors.initials: L
authors.lastname: Wang
authors.affiliation: Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, Connecticut, United States of America.
authors.forename: David W
authors.initials: DW
authors.lastname: Rowe
authors.affiliation: Department of Materials Science & Engineering, University of Connecticut, Storrs, Connecticut, United States of America.
authors.forename: Mei
authors.initials: M
authors.lastname: Wei
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000378:metabolism / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D003094:Collagen / Q000378:metabolism*; D017886:Durapatite / Q000378:metabolism*; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D005269:Femur / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D051379:Mice; D010012:Osteogenesis / Q000187:drug effects*; D010539:Permeability / Q000187:drug effects; D013977:Tibia / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D003094:Collagen; D017886:Durapatite