Membranes
. . .
. . .
ials .
terials
. . .
. . .
4.1. Chitin membranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Biotechnology Advances 29 (2011) 322–337
Contents lists available at ScienceDirect
Biotechnology Advances
j ourna l homepage: www.e lsev ie r.com/ locate /b iotechadv4.2. Chitosan membranes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
4.3. Chitosan-based composite films. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
4.4. Membranes based on chitosan-silver (Ag) nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
4.5. Membranes based on chitosan-zinc oxide (ZnO) nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
5. Chitin and chitosan scaffolds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
6. Chitin and chitosan sponges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335⁎ Corresponding author. Tel.: +91 484 2801234; fax:
E-mail addresses: rjayakumar@aims.amrita.edu, jaya
0734-9750/$ – see front matter © 2011 Elsevier Inc. Al
doi:10.1016/j.biotechadv.2011.01.005. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
3.2. Chitosan-based hydrogels . . .
4. Chitin and chitosan membranes . . . .Hydrogels
Sponges
Wound dressing
Contents
1. Introduction . . . . . . . . . .
2. Chitin and chitosan fibers . . . .
2.1. Chitin-based fibrous mater
2.2. Chitosan-based fibrous ma
3. Chitin and chitosan hydrogels . .
3.1. Chitin-based hydrogels . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326+91 484 2802020.
kumar77@yahoo.com (R. Jayakumar).
l rights reserved.Scaffolds
NanofibersChitin
ChitosanResearch review paper
Biomaterials based on chitin and chitosan in wound dressing applications
R. Jayakumar a,⁎, M. Prabaharan b, P.T. Sudheesh Kumar a, S.V. Nair a, H. Tamura c
a Amrita Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidhyapeetham University, Cochin-682 041, India
b Department of Chemistry, Faculty of Engineering and Technology, SRM University, Kattankulathur-603 203, India
c Faculty of Chemistry, Materials and Bioengineering, Kansai University, Osaka-564-8680, Japan
a b s t r a c ta r t i c l e i n f o
Article history:
Received 28 July 2010
Received in revised form 2 December 2010
Accepted 14 January 2011
Available online 22 January 2011
Keywords:
Wound dressing is one of the most promising medical applications for chitin and chitosan. The adhesive
nature of chitin and chitosan, together with their antifungal and bactericidal character, and their permeability
to oxygen, is a very important property associated with the treatment of wounds and burns. Different
derivatives of chitin and chitosan have been prepared for this purpose in the form of hydrogels, fibers,
membranes, scaffolds and sponges. The purpose of this review is to take a closer look on the wound dressing
applications of biomaterials based on chitin, chitosan and their derivatives in various forms in detail.
© 2011 Elsevier Inc. All rights reserved.

1. Introduction
Healing restores integrity of the injured tissue and prevents
organisms from deregulation of homeostasis. The treatment of
wounds has evolved from ancient times. Initially, application of
dressingmaterial was aimed at inhibition of bleeding, and protection
of the wound from environmental irritants as well as water and
electrolyte disturbances. The skin plays an important role in
homeostasis and the prevention of invasion by microorganisms.
Skin generally needs to be covered with a dressing immediately after
it is damaged. There are three categories of wound dressing: biologic,
synthetic and biologic-synthetic. Alloskin and pigskin are biologic
dressings commonly used clinically, but they have some disadvan-
tages, such as limited supplies, high antigenicity, poor adhesiveness
and risk of cross contamination. Synthetic dressings have a long shelf
life, induce minimal inflammatory reaction and carry almost no risk
of pathogen transmission. Biologic-synthetic dressings are bilayered
and consist of high polymer and biologic materials (Bruin et al.,
1990; Matsuda et al., 1990a, 1990b; Suzuki et al., 1990). These three
categories of wound dressing are all used frequently in the clinical
setting, but none is without disadvantages.
An ideal dressing should maintain a moist environment at the
wound interface, allow gaseous exchange, act as a barrier to
In recent years, a large number of research groups are dedicated to
producing a new and improved wound dressing by synthesizing and
modifying biocompatible materials (Shibata et al., 1997; Draye et al.,
1998; Ulubayram et al., 2001). Current strategies are also focused on
the acceleration of the wound repair by systematically designed
dressing materials. In particular, efforts are focused on the use of
biologically derivedmaterials such as, chitin and its derivatives, which
are capable of accelerating the healing processes at molecular,
cellular, and systemic levels. Chitin is a readily available and
inexpensive biological material obtained from invertebrate's skeleton
aswell as the cell wall of fungi (Fig. 1). It is a linear 1, 4-linked polymer
composed of N-acetyl-D-glucosamine residues. Chitin and its deriv-
ative, chitosan, are biocompatible, biodegradable, nontoxic, anti-
microbial and hydrating agents. Due to these properties, they show
good biocompatibility and positive effects on wound healing. Previous
studies have shown that chitin-based dressings can accelerate repair
of different tissues facilitate contraction of wounds, and regulate
secretion of the inflammatory mediators such as interleukin 8,
prostaglandin E, interleukin 1 β, and others (Bottomley et al., 1999;
Willoughby and Tomlinson, 1999).
Chitosan provides a non-protein matrix for 3D tissue growth and
activates macrophages for tumoricidal activity. It stimulates cell
proliferation and histoarchitectural tissue organization. Chitosan is a
323R. Jayakumar et al. / Biotechnology Advances 29 (2011) 322–337microorganisms and remove excess exudates. It should also be non-
toxic, non-allergenic, nonadherent and easily removed without
trauma, it should be made from a readily available biomaterial that
requires minimal processing, possesses antimicrobial properties and
promotes wound healing.
In the 1980s, collagen and glycosaminoglycan dermal skin mem-
branes were studied as substrates for cultured human epidermal
keratinocytes. A nonporous surface of collagen- glycosaminoglycan
was laminated to the membranes to provide a planar substrate for
cultured epidermal keratinocytes (O’Connor et al., 1981). The optimized
membranes were found to be suitable substrates for the culture of
human epidermal keratinocytes, and together with the cells yielded a
composite material that was histologically similar to skin (Dagalakis et
al., 1980a, 1980b; Yannas et al., 1980, 1981; Boyce et al., 1988; Chang et
al., 1988; Hansbrough et al., 1989;Matsuda et al., 1990a, 1990b). Bilayer
artificial skin composed of a silicone membrane and a collagen sponge
layer containing glycosaminoglycans was first developed by Yannas et
al. (1981). They reported that glycosaminoglycans contained in the
collagen sponge layer contributed to the function of the artificial skin.Fig. 1. Structure of chhemostat, which helps in natural blood clotting and blocks nerve
endings reducing pain (Fig. 2). Chitosan will gradually depolymerize to
release N-acetyl-β-D-glucosamine, which initiates fibroblast prolifera-
tion, helps in ordered collagendeposition and stimulates increased level
of natural hyaluronic acid synthesis at the wound site. It helps in faster
wound healing and scar prevention (Paul and Sharma, 2004).
Chitin and chitosan can be easily processed into hydrogels
(Nagahama et al., 2008a, 2008b; Tamura et al., 2010), membranes
(Yusof et al., 2003; Marreco et al., 2004; Jayakumar et al., 2007, 2008,
2009; Madhumathi et al., 2009), nanofibers (Shalumon et al., 2009,
2010; Jayakumar et al., 2010e), beads (Yusof et al., 2001; Jayakumar
et al., 2006), micro/nanoparticles (Prabaharan and Mano, 2005;
Prabaharan, 2008; Anitha et al., 2009, 2010; Dev et al., 2010), scaffolds
(Peter et al., 2009, 2010; Prabaharan and Jayakumar, 2009;Maeda et al.,
2008) and sponges (Muramatsu et al., 2003; Portero et al., 2007) for
various types of biomedical applications such as drug and gene delivery
(Prabaharan and Mano, 2005; Jayakumar et al., 2010a), wound healing
(Jayakumar et al., 2005, 2007, 2010b, 2010c; Tamura et al., 2010) and
tissue engineering (Jayakumar et al., 2005, 2010d; Tamura et al., 2010).itin and chitosan.