ENZYMATICALLY TRIGGERED IN SITU GEL-FORMING BIOMATERIALS FOR REGENERATIVE MEDICINE - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 123

to cells. Enzyme-triggered hydrogels have many advantages as
injectable scaffolds, which can overcome the limitations of previ-
ous injectable biomaterials. Among them, HRP-catalyzed systems
are probably more advantageous than other enzyme-triggered sys-
tems that show a slow gelation time of several tens to hundreds
of minutes and relatively lower mechanical strength. The substrate
for enzyme catalysis is also important for achieving successful scaf-
folding for tissue regeneration. Synthetic polymer derivatives do
not retain their bioactivity, even though they are varied in chemical
design. Natural biomolecules containing polysaccharides and pro-
teins/peptides have disadvantages such as relatively poor physical
andmechanicalpropertiesdespitegoodbiocompatibilityandbioac-
tivity. Therefore, a rational design of both advantages can be effec-
tive, for example, the joint of synthetic and natural polymers. To our
knowledge,enzyme-triggeredhydrogelshaveundoubtedlyprovided
an advance that allows not only the delivery of cells safely into the
body but also the immobilization of bioactive macromolecules. On
the basis of these advances, the next challenges of injectable hydro-
gels for intelligent scaffolds will be to design and decorate microen-
vironmentsin a matrix to take the place of natural ECMs.
Acknowledgments
ThisworkwassupportedbytheNano-BiotechnologyProject(Rege-
nomics) (B020214) and the Pioneer Research Program for con-
vergingtechnology(M10711060001-08M1106-00110) throughthe
Korea Science and Engineering Foundation funded by the Ministry
of Education,Science and Technology.
References
1. T. R. Hoare and D. S. Kohane, Polymer , 49 ,1993(2008).
2. B.J.Baroli, Pharm. Sci ., 96 ,2197 (2007).
3. E. Martin, C. R. Simone, G. S. Ronald, S. M. Blanca, J. A. Hubbell, E. W.
Franz, and P. L. Matthias, Biomacromolecules , 8 ,3000 (2007).