title: Pre-osteoblast infiltration and differentiation in highly porous apatite-coated PLLA electrospun scaffolds.
abstract: Electrospun polymer/apatite composite scaffolds are promising candidates as functional bone substitutes because of their ability to allow pre-osteoblast attachment, proliferation, and differentiation. However these structures usually lack an adequate pore size to permit sufficient cell migration and colonization of the scaffold. To overcome this limitation, we developed an apatite-coated electrospun PLLA scaffold with varying pore size and porosity by utilizing a three-step water-soluble PEO fiber inclusion, dissolution, and mineralization process. The temporal and spatial dynamics of cell migration into the scaffolds were quantified to determine the effects of enhanced pore size and porosity on cell infiltration. MC3T3-E1 pre-osteoblast migration into the scaffolds was found to be a function of both initial PEO content and time. Scaffolds with greater initial PEO content (50% and 75% PEO) had drastically accelerated cell infiltration in addition to enhanced cell distribution throughout the scaffold when compared to scaffolds with lower PEO content (0% and 25% PEO). Furthermore, scaffolds with an apatite substrate significantly upregulated MC3T3-E1 alkaline phosphatase activity, osteocalcin content, and cell-mediated mineralization as compared to PLLA alone. These findings suggest that such a scaffold enhances pre-osteoblast infiltration, colonization, and maturation in vitro and may lead to overall improved bone formation when implanted in vivo.
authors.affiliation: School of Biomedical Engineering and Sciences, Virginia Tech - Wake Forest University, Blacksburg, VA 24061, USA. bwhited@vt.edu
authors.forename: Bryce M
authors.initials: BM
authors.lastname: Whited
authors.forename: Jon R
authors.initials: JR
authors.lastname: Whitney
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Hofmann
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.forename: Marissa N
authors.initials: MN
authors.lastname: Rylander
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001031:Apatites / Q000494:pharmacology*; D001696:Biomechanical Phenomena / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects*; D002465:Cell Movement / Q000187:drug effects*; D055119:Elastic Modulus / Q000187:drug effects; D007211:Indoles / Q000378:metabolism; D019344:Lactic Acid / Q000494:pharmacology*; D008422:Materials Testing / Q000379:methods*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D008903:Minerals; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D015675:Osteocalcin / Q000378:metabolism; D011091:Polyesters; D011108:Polymers / Q000494:pharmacology*; D016062:Porosity / Q000187:drug effects; D013718:Tensile Strength / Q000187:drug effects; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001031:Apatites; D007211:Indoles; D008903:Minerals; D011091:Polyesters; D011108:Polymers; D015675:Osteocalcin; D019344:Lactic Acid; C033616:poly(lactide); C007293:DAPI; D000469:Alkaline Phosphatase; D002118:Calcium