Over six million fractures are sustained in the United States each year and 5-10 percent of those result in nonunion. The current most efficacious treatment to stimulate bone regeneration involves harvesting and transplanting autologous bone chips from the iliac crest of the patient to the injury site. However, donor site morbidity and pain, lack of structural integrity, and limited graft material volume are significant drawbacks. Tissue engineering strategies that combine porous biomaterial scaffolds with cells capable of osteogenesis or bioactive proteins have shown promise as effective bone graft substitutes. However, attempts to culture bone tissue-engineering constructs thicker than 1 mm in vitro have typically resulted in a shell of viable cells and mineralized matrix surrounding a necrotic core due to the absence of a vascular supply.
To improve mass transport and nutrient exchange, 3-D in vitro experiments have shown an increase in cell viability and function and mineral deposition within media perfused cell-seeded scaffolds compared to static controls. In addition to improved mass transport, perfusion produces flow mediated shear stresses, which have been shown to upregulate osteoblast activity. BISS is developing bioreactors that can perfuse cell-seeded scaffolds and deliver prescribed pulsatile flow regimes to stimulate mineral growth. Additionally, these bioreactors facilitate temporal monitoring of mineral deposition via micro-CT scanning.
|Physiologic Requirements:||BISS OsteoGen Solutions:|
|Convective Nutrient Transport:||Perfusion Capabilities|
|Uniform Cell Density:||Hydrogel Seeding In Situ|
|Mechanical Stimulation:||Mechanical and Wire grip options|
|Native Physiological Structure and Function:||Biomimetic in vitro Environment|
The OsteoGen architecture provides a physiologic support system that enhances metabolic conditions for cell growth and maintenance in a 3-D environment. Physiologic parameters are feedback-controlled for culture reproducibility.