Open AccessBone tissue engineering in a rotating bioreactor using a microcarrier matrix system
Author(s) -
Botchwey E. A.,
Pollack S. R.,
Levine E. M.,
Laurencin C. T.
Publication year - 2001
Publication title -
journal of biomedical materials research
Language(s) - English
Resource type - Journals
eISSN - 1097-4636
pISSN - 0021-9304
DOI - 10.1002/1097-4636(200105)55:2<242::aid-jbm1011>3.0.co;2-d
Subject(s) - microcarrier , bioreactor , materials science , osteoblast , tissue engineering , biomedical engineering , matrix (chemical analysis) , alkaline phosphatase , scaffold , in vitro , composite material , chemistry , biochemistry , cell , medicine , organic chemistry , enzyme
A novel approach was utilized to grow in vitro mineralized bone tissue using lighter‐than‐water, polymeric scaffolds in a high aspect ratio rotating bioreactor. We have adapted polymer microencapsulation methods for the formation of hollow, lighter‐than‐water microcarriers of degradable poly(lactic‐ co ‐glycolic acid). Scaffolds were fabricated by sintering together lighter‐than‐water microcarriers from 500 to 860 μm in diameter to create a fully interconnected, three‐dimensional network with an average pore size of 187 μm and aggregate density of 0.65 g/mL. Motion in the rotating bioreactor was characterized by numerical simulation and by direct measurement using an in situ particle tracking system. Scaffold constructs established a near circular trajectory in the fluid medium with a terminal velocity of 98 mm/s while avoiding collision with the bioreactor wall. Preliminary cell culture studies on these scaffolds show that osteoblast‐like cells readily attached to microcarrier scaffolds using controlled seeding conditions with an average cell density of 6.5 × 10 4 cells/cm 2 . The maximum shear stress imparted to attached cells was estimated to be 3.9 dynes/cm 2 . In addition, cells cultured in vitro on these lighter‐than‐water scaffolds retained their osteoblastic phenotype and showed significant increases in alkaline phosphatase expression and alizarin red staining by day 7 as compared with statically cultured controls. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res 55: 242–253, 2001