title: Marrow stromal osteoblast function on a poly(propylene fumarate)/beta-tricalcium phosphate biodegradable orthopaedic composite.
abstract: The objective of this study was to assess the osteoconductivity of a poly(propylene fumarate)/beta-tricalcium phosphate (PPF/beta-TCP) composite in vitro. We examined whether primary rat marrow stromal cells would attach, proliferate, and express differentiated osteoblastic function when seeded on PPF/beta-TCP substrates. Attachment studies showed that a confluent monolayer of cells had adhered to the substrates within an 8 h time frame for marrow stromal cells seeded at confluent numbers. Proliferation and differentiated function of the cells were then investigated for a period of 4 weeks for an initial seeding density of 42,000 cells/cm2. Rapid proliferation during the first 24 h as determined by 3H-thymidine incorporation was mirrored by an initial rapid increase in total cell number by DNA assay. A lower proliferation rate and a gradual increase in cell number persisted for the remainder of the study, resulting in a final cell number of 128,000 cells/cm2. Differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity and osteocalcin (OC) production throughout the time course. Both markers of osteoblastic differentiation increased significantly over a 4-week period. By day 28, cells grown on PPF/beta-TCP reached a maximal ALP activity of 11 (+/- 1) x 10(-7) micromol/min/cell, while the OC production reached 40 (+/- 1) x 10(-6) ng/cell. These data show that a PPF/beta-TCP composite exhibits in vitro osteoconductivity similar to or better than that of control tissue culture polystyrene.
authors.affiliation: Departments of Chemical Engineering and Bioengineering, Rice University, Houston, TX 77005-1892, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Peter
authors.forename: L
authors.initials: L
authors.lastname: Lu
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.forename: A G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D020341:Absorbable Implants; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D015415:Biomarkers; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D018786:Bone Substitutes / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D002448:Cell Adhesion; D002455:Cell Division; D004247:DNA / Q000032:analysis; D005650:Fumarates / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015675:Osteocalcin / Q000096:biosynthesis; D011126:Polypropylenes / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D015415:Biomarkers; D018786:Bone Substitutes; D002130:Calcium Phosphates; D005650:Fumarates; D011126:Polypropylenes; C097850:poly(propylene fumarate); D015675:Osteocalcin; D004247:DNA; D000469:Alkaline Phosphatase