Biomedical Engineering Reference
In-Depth Information
functionalities as ECM recognition elements or bioactive substances which
induce tissue in-growth, it is possible to design the MG scaffolds with bioactive
ligands. Besides, most of the MGs withstand sterilization by autoclaving [Plieva
et al., 2004a,b] and can be dried and stored in dried state followed by fast re-
swelling prior to use.
14.7 CONCLUSION AND OUTLOOK
Macroporous gels (MGs) with a broad variety of morphologies are prepared
using cryotropic gelation technique meaning gelation at subzero temperatures.
These highly elastic hydrophilic materials can be produced from practically any
gel forming system with a broad range of porosities, from elastic and porous gels
with pore size up to 1.0
μ
m till elastic and sponge-like gels with pore size up to
200
m. The versatility of cryogelation technique is demonstrated by use of differ-
ent routes of gel formation (hydrogen bonding, chemical cross-linking of poly-
mers, free radical cross-linking polymerization reaction) mainly in an aqueous
medium. Proper control over a solvent crystallization (formation of solvent crys-
tals) and the rate of chemical reaction during the cryogelation allows for the
reproducible preparation of cryogels with tailored properties. The gel surface
chemistry can be designed depending on particular application. High mechanical
strength of MGs combined with unique tissue-like elasticity and uniform porous
structure with large interconnected pores will allow for numerous applications of
MGs in tissue engineering fi eld. The environmentally-friendly way of producing
the MGs where no organic solvents are involved makes this approach favorable
compared to the other mostly-used techniques for the production of macro-
porous biomaterials. Biodegradable as well as non-degradable MGs are produced
depending on the chemistry of the gelation system.
μ
ACKNOWLEDGMENTS
The authors acknowledge all authors whose works are cited in this chapter. The
support from the Swedish Foundation for Strategic Research (area of Chemistry
and Life sciences), Department of Biotechnology (DBT) and Department of
Science and Technology (DST), Ministry of Science and Technology, India is also
acknowledged.
REFERENCES
Akyurt M , Zaki G , Habeebullah B . 2002 . Freezing phenomena in ice - water systems . Energ.
Conv. Manag. 43 : 1773 - 1789 .
Bajpai A , Saini R . 2005a . Preparation and characterization of biocompatible spongy cryo-
gels of poly(vinyl alcohol)-gelatin and study of water sorption behaviour. Polym. Int. 54:
1233 - 1242 .
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