(OP 141) Home, Sweet Home: Recreating the Native Bony Environment In vitro Using a Novel Dynamic Cell-Culture System for Bone-Biology Research

• Published in: Tissue engineering. Part A 2008-05, Vol.14 (5), p.740-740
• Main Authors: Allori, A C, Sailon, A M, Ricci, J L, Warren, S M
• Format: Article
• Language: English
• ISSN: 1937-3341; 1937-335X

Introduction: Traditional cell-culture methods are ill-suited to study the intricacies of bone biology because they ignore the three-dimensionality of meaningful cellular networks and the lacunocanalicular system. Reliance on nutrient diffusion limits scaffolds to 2-3 mm thickness. Static culture also ignores the importance of mechanical loading in regulating bone metabolism. A novel flow perfusion system was developed to overcome these limitations. Both bioreactor and osteoconductive/osteoinductive scaffolds resulted from evolutionary outgrowth of the native structure/function of bone and the design requirements crucial to successful experimentation. Methods: Eight adaptable chambers house cylindrical scaffolds, up to 24 mm diameter x 10 mm thickness. A multi-channel peristaltic pump draws medium from parallel reservoirs and perfuses it through each scaffold (0.3-30 mL/min). Hermetically sealed valves permit sampling of medium. A gas-permeable membrane permit gas exchange. Tubing was selected to withstand continuous perfusion for >2 months without leakage. Porous scaffolds were manufactured using a novel 3D bioprinting process. These scaffolds were composed of hydroxyapatite/tricalcium phosphate with variable thicknesses, strut sizes, and pore sizes. Results: Fluid shear stress ranged from 0.04-4 dyn/cm super(2) at the cellular level and are described by finite element modeling. Scaffold architecture is characterized by micro-CT and scanning electron microscopy. Osteoblastic networks and canalicular channels are visualized by fluorescent confocal microscopy. Conclusions: Unlike spinner flasks and FlexCell devices, this novel system simulates the natural 3D lacunocanalicular system of native bone, ensuring chemotransportation throughout thick 3D scaffolds and allowing for the study of bone biological and bio-mechanical processes in vitro.