Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 4, pp. 545−551.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © A.A. Yusova, I.M. Lipatova, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 4, pp. 585−591.
Mechanically Initiated Gelation in Solutions
of Chitosan with Low Degree of Deacetylation
A. A. Yusova and I. M. Lipatova
Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Received February 7, 2013
Abstract—Mechanical activation of solutions of chitosan with low degree of deacetylation under the conditions
of combined action of ultrasound and high shear stresses in a rotary pulse apparatus leads to the formation of
physical hydrogels. Films capable to retain at repeated swelling up to 5000% water without dissolution were
prepared by drying of the hydrogels.
Hydrogels of natural biologically active polymers
have attracted growing attention in the past decades.
Unique properties of such hydrogels allow the devel-
opment of new materials based on them for biotech-
nological, biomedical, pharmacological, and medical
purposes. Hydrogels of chitosan, a biologically active
polysaccharide of natural origin, show promise for this
purpose. This polymer is biocompatible, biodegradable,
and nontoxic; it exhibits antimicrobial and hemostatic
properties. Therefore, hydrogels based on it are of inter-
est for use as wound coatings and as matrices for drugs
of prolonged action with controllable drug release [1, 2].
The 3D framework of chitosan hydrogels is formed
by polyelectrolytic binding , covalent cross-linking by
the condensation mechanism involving amino groups ,
or radiation-induced cross-linking . The main method
for preparing covalently cross-linked chitosan hydrogels
is cross-linking with glutaraldehyde ; however, side
Fig. 1. Photographs of ﬁ lms prepared from (a) initial and (b) mechanically activated chitosan solutions (с = 1 wt %).