ARTIFICIAL BINDING GROWTH FACTORS - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 350

Chen et al . 22 , 51 subcutaneously implanted demineralized bone
matrix(DBM)combinedwithcollagen-bindingBMP2(BMP2-h)and
showed ectopic bone formation in rats. They also showed that
BMP2-h-loaded DBM was effective in the repair of rabbit mandible
bonedefects,withane ciencythatwas10%-20%higherthanthat
of nativeBMP-2/DBM.
The examination of the effects of fibrin-binding BMP2 (TG-pI-
BMP2) in a rat craniotomy defect model 31 revealed that the healing
area was 76% larger than that observed for native BMP2. In addi-
tion to the craniofacial bones, this study was extended to the repair
of long bones,as assessed by bonebridging.
17.5 Concluding Remarks
The major advantage of the gene-engineered binding growth fac-
tors is that the protein is able to bind to biological substances and
artificial materials that can hardly retain native growth factors. In
addition, the dose can be reduced. In some designs, the stability of
theresultantmoleculescanbeprolonged.Theseadvantagesarecru-
cialtotheproductionofscaffoldmaterialsequippedwithadditional
functions.
Various binding growth factors were produced and examined
over the past 15 years. Although fusion proteins with insu cient
binding properties or with reduced biological activities have been
reported in the early stages of these studies, recently designed pro-
teinsexhibitgoodproperties.Itnowseemspossiblethatanygrowth
factor can be engineered to have desired binding properties (at
least for matrix binding), without substantial loss of native activ-
ity. In addition, there has been an increase in the number of reports
showingthee cacyoftheengineeredproteinsduringtissuerepair,
although there remain unsolved issues. Thus, the binding growth
factors are considered as promising materials for regenerative
medicine.
References
1. S. Werner and R. Grose, Physiol. Rev., 83 ,835 (2003).
2. G.F. Whalen,Y.Shing, and J.Folkman, Growth Factors, 1 , 157 (1989).