Abstract
Introduction
Bone tissue engineering approaches are an emerging strategy to treat bone defects, and commonly involve the delivery of osteogenic cells and/or drugs via a porous scaffold. We have been exploring an alternative injectable approach for drug delivery that would obviate the need for invasive surgery.
Hypothesis
Sucrose Acetate Isobutyrate (SAIB) is a sucrose-based ester that is a highly viscous semi-solid. Diluting SAIB with 10–20% ethanol markedly reduces its viscosity, with ethanol diffusing rapidly after in vivo injection. This phase transitioning property makes SAIB an ideal candidate for bone tissue engineering.
Materials and methods
The capacity of SAIB to act as a delivery system for recombinant human BMP-2 (rhBMP-2) was tested in a mouse ectopic bone formation model. In this model SAIB was used to deliver 0 to 10μg rhBMP-2. Next, SAIB was compared with porous collagen scaffold used clinically to delivery rhBMP-2 in a head-to-head trial. Commercial SAIB and SAIB produced in-house were also compared. Bone volumes were quantified by μCT.
Discussion
Bone was found to form with as little as 2μg rhBMP-2 when delivered with SAIB. Injected SAIB also showed minimal inflammatory response and rapid breakdown, with bone formation occurring between one and two weeks.
Conclusion
SAIB was found to be an effective delivery system for rhBMP-2 with translational utility. Future work will be required to examine the upscaling of this delivery system.
