Biomedical Engineering Reference
In-Depth Information
of TGF-β induced significant ectopic bone compared with TGF-β injection. As a flexible delivery
system, these scaffolds can be adapted for sustained release of many different growth factors and bio-
molecules. Significantly ectopic bone formation also was observed using these systems when peptide
amphiphile solutions and BMP-2 were subcutaneously injected to the back of the rat [49] .
Controlled release of plasmid DNA encoded osteogenic growth factors have been attempted to
induce significant bone regeneration. Our recent studies have indicated that incorporation of plasmid
DNA encoding BMP-2 into collagen sponge significantly enhanced in-vivo ectopic bone formation
[50-54] . Controlled release of plasmid DNA-BMP-2 from cationized gelatin enhanced gene transfec-
tion of mesenchymal stem cells (MSCs) and formed genetically engineered MSCs. Homogeneous
bone formation was histologically observed throughout the genetically engineered MSCs 4 weeks
after subcutaneous implantation of scaffolds into the back of rats. The bone mineral density (BMD)
of new bone formed at the implanted sites of scaffolds seeded with the genetically engineered MSC
were significantly higher compared with scaffolds seeded with naked plasmid DNA.
14.6 CONCLUSIONS
This chapter broadly discussed the basic principles underlying controlled release technology for bone
regeneration and gave a general overview of different kinds of release systems. The potential applica-
tions of polymeric materials that can be applied for fabricating wider range of novel biomaterials for
the use in controlled release systems are discussed with reference to current literature. The growth fac-
tors delivery systems were also described. These macroscopic structures have inspired the research-
ers to use them in various areas of science such as biotechnology, nanotechnology, and medicine.
However, it is necessary to design new and other alternative methods if we face any problems using
the current technology in delivering biomolecules drug; such as protein, growth factors, and DNA.
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