Reactive & Functional Polymers 46 (2000) 1–27www.elsevier.com/locate/react
A review of chitin and chitosan applications
*Majeti N.V. Ravi Kumar
Department of Chemistry
University of Roorkee
Received 24 January 2000; received in revised form 20 June 2000; accepted 25 June 2000
Chitin is the most abundant natural amino polysaccharide and is estimated to be produced annually almost as much ascellulose. It has become of great interest not only as an underutilized resource, but also as a new functional material of highpotential in various ﬁelds, and recent progress in chitin chemistry is quite noteworthy. The purpose of this review is to take acloser look at chitin and chitosan applications. Based on current research and existing products, some new and futuristicapproaches in this fascinating area are thoroughly discussed.
2000 Elsevier Science B.V. All rights reserved.
Beads; Biotechnology; Chitin; Chitosan; Controlled drug delivery; Fibers; Nanoparticles; Hydrogels; Tablets; Transdermaldevices
position C-2 replaced by an acetamido group.Like cellulose, it functions naturally as a struc-Chitin, a naturally abundant mucopolysac-tural polysaccharide. Chitin is a white, hard,charide, and the supporting material of crusta-inelastic, nitrogenous polysaccharide and theceans, insects, etc., is well known to consist of major source of surface pollution in coastal2-acetamido-2-deoxy-
-glucose through a
areas. Chitosan is the
4) linkage. Chitin can be degraded byof chitin, although this
-deacetylation is al-chitinase. Its immunogenicity is exceptionallymost never complete. A sharp nomenclaturelow, in spite of the presence of nitrogen. It is awith respect to the degree of
-deacetylationhighly insoluble material resembling cellulosehas not been deﬁned between chitin andin its solubility and low chemical reactivity. Itchitosan [1,2]. The structures of cellulose, chitinmay be regarded as cellulose with hydroxyl atand chitosan are shown in Fig. 1. Chitin andchitosan are of commercial interest due to theirhigh percentage of nitrogen (6.89%) compared
This paper is dedicated to Professor M.N.V. Prasad, Ph.D.,
to synthetically substituted cellulose (1.25%).
FNIE (New Delhi), DSc. (hc Colombo), School of Life Sciences,
This makes chitin a useful chelating agent .
University of Hyderabad, Hyderabad, India, who inspired me withhis scientiﬁc approach, honesty and human warmth.
As most of the present-day polymers are syn-
*Post Bag No. 29, Roorkee 247 667, India. Fax:
thetic materials, their biocompatibility and
biodegradability are much more limited than
email@example.com (M.N.V. RaviKumar).
those of natural polymers such as cellulose,
1381-5148/00/$ – see front matter
2000 Elsevier Science B.V. All rights reserved.PII: S1381-5148(00)00038-9