title: Effect of endothelial differentiated adipose-derived stem cells on vascularity and osteogenesis in poly(D,L-lactide) scaffolds in vivo.
abstract: Prevascularization of engineered bony constructs can potentially improve in vivo viability. However, the effect of endothelial cells on osteogenesis is unknown when placed in poly(D,L-lactide) (PLA) scaffolds alone. Adipose-derived stem cells (ASCs) have the ability to differentiate into both osteoblasts and endothelial cells by culture in specific media. We hypothesized that ASC-derived endothelial cells would improve vascularity with minimal contribution to bone formation when placed in scaffold alone. ASCs were successfully differentiated into endothelial cells (ASC-Endo) and osteoblasts (ASC-Osteo) using media supplemented with vascular endothelial growth factor and bone morphogenic protein 2, respectively. Tissue-engineered constructs were created with PLA matrices containing no cells (control), undifferentiated ASCs (ASCs), osteogenic-differentiated ASCs (ASC-Osteo), or endothelial differentiated ASCs (ASC-Endo), and these constructs were evaluated in critical-size Lewis rat calvarial defect model (n = 34). Eight weeks after implantation, the bone volume and microvessel population of bony constructs were evaluated by micro-computed tomography analysis and histologic staining. Bone volumes for ASCs and ASC-Osteo constructs, 0.7 and 0.91 mm(3), respectively, were statistically greater than that for ASC-Endo, 0.28 mm(3) (P < 0.05). There was no statistical difference between the PLA control (0.5 mm(3)) and ASC-Endo (0.28 mm(3)) constructs in bone formation. The percent area of microvessels within constructs was highest in the ASC-Endo group, although it did not reach statistical significance (0.065). Prevascularization of PLA scaffold with ASC-Endo cells will not increase bone formation by itself but may be used as a cell source for improving vascularization and potentially improving existing osteoblast function.
authors.affiliation: Division of Plastic Surgery, UC Davis School of Medicine, Sacramento, CA 95817, USA. david.sahar@ucdmc.ucdavis.edu
authors.forename: David E
authors.initials: DE
authors.lastname: Sahar
authors.forename: John A
authors.initials: JA
authors.lastname: Walker
authors.forename: Howard T
authors.initials: HT
authors.lastname: Wang
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Stephenson
authors.forename: Amita R
authors.initials: AR
authors.lastname: Shah
authors.forename: Naveen K
authors.initials: NK
authors.lastname: Krishnegowda
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Wenke
mesh_terms: D000273:Adipose Tissue / Q000166:cytology*; D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D001861:Bone Regeneration / Q000502:physiology; D002454:Cell Differentiation; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology; D007150:Immunohistochemistry; D018919:Neovascularization, Physiologic; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis / Q000502:physiology*; D011091:Polyesters / Q000494:pharmacology*; D051381:Rats; D011917:Rats, Inbred Lew; D013234:Stem Cells / Q000166:cytology*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D055114:X-Ray Microtomography
chemical_list: D011091:Polyesters; C033616:poly(lactide)