The complex world of polysaccharides edited by Desiree Nedra Karunaratne

 

The Complex World of Polysaccharides 

 

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Figure 7.

 These are some ways you can shape the chitosan: films, gels, microspheres, tubes, sponges, 

powder 

21. Artificial skin 

The preparation of artificial skin by natural materials such as gelatin, pectin, starch, 

cellulose, alginate, chitin, collagen, polyamino acids, and dextran has been established to 

enhance the healing process. The structures of these natural materials are analogs of protein 

and growth factor structures in the human body that may be more relevant for stimulating 

the appropriate hysiological responses required for cellular regeneration and tissue 

reconstructing in wounds [146]. 

Dressing materials based on chitin, chitosan and derivatives are well-known on the market, 

and are produced mainly in Japan and the US. JEX KK Co produces composite dressings 

made of synthetic resins, chitosan and materials of collagen and acetylchitiosan. Eisai Co is 

manufacture of chitin dressings in sponge form (Chitopack C®) or a PET non-woven 

modified with chitin (Chitopack C®). The Japanese Unitika Co offers a dressing non-woven 

of chitosan fibres. The American 3M proposes a chitosan gel preparation (Tegasorb®) and a 

hydrocolloid (Tegaderm®) designed for the healing of extensive internal 

wounds.ChorioChit sponge is a biological dressing obtained by lyophilisation of human 

placenta blended with MCCh. 

22. Scaffold for the regeneration of tissue 

Chitin and its derivatives have been used as scaffolds for bone and other natural tissue 

regeneration [147] as well as structures by which three-dimensional formation of tissues are 

supported [148]. While looking for a good material for a good scaffold, there are at least four 

important factors that should be taken into account: (1) ability to form temporary matrix, (2) 

ability to form porous structure for tissue to grow, (3) biodegradability, and finally (4) non-

toxic byproducts from the digestion [149,150]. Thus, neither the physical nor biological 

properties of such biomaterials should be ignored [147]. Chitin and its derivatives have been 

shown to possess these criteria. 

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Is Chitosan a New Panacea? Areas of Application 

 

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23. Haemostasis and wound healing 

Hemostasis through blood coagulation is an important step for wound healing. The main 

cellular components in blood coagulation are platelets. It has been shown that chitosan has a 

hemostatic effect [151]. Okamoto et al 2003, reported that chitin is an effective agent for 

hemostasis maintenance through aggregating platelets, and suggested that the effect of 

chitin and chitosan is due to both physical and chemical properties of these biopolymers, 

especially their amino groups [152]. 

Haemostatic dressings containing chitin and chitosan as bioactive agents are also well 

known, notably the Syvek patch, RDH (Marine Polymer Technologies), Clo-Sur PAD 

(Medtronic-Scion), Chito-Seal (Abbot), the M-Patch and Trauma DEX (Medafor). 

24. Peripheral nerve prosthesis 

Prosthesis is made from various forms of utility polysaccharides. The main objective of 

research is to develop replacement implants that will not be rejected by the body of the 

recipient and offering the ability to regenerate damaged nerve. Because chitin has high 

mechanical strength under physiological conditions (low for chitosan) chitin has the 

potential to be a good nerve guidance channel. Ferier et al, 2005, used this fact and made 

chitin tubes that could support nerve cell adhesion and neurite outgrowth [153]. In a 

research related to nerve regeneration, it was shown that rabbits with the crushed 

common peroneal nerve exhibit better improvement in peripheral nerve regeneration in 

the presence of chitooligosaccharide. As a result, chito-oligosaccharide can be used as 

neuroprotective material with an ability to improve injured peripheral nerve 

regeneration [154]. 

25. Immunology 

The key property of chitin-derived products for application in various biomedical 

applications is the immuno-modulating effect [155,156]. Some mechanisms of immuno-

enhancement activity of chitin and its derivatives have been reported, for example, 

chitosan exhibited the ability to boost NO production from macrophages in the 

presence of interferon-γ (IFN-γ) through the NF-κB signaling pathway [157]. Minami et 

al. in 1998 found that chitin and chitosan affected C3 and C5 components of 

complement system and concluded that complement system is activated by chitin and 

chitosan through the alternative pathway. After activating the complement, C5 is 

produced followed by an increase in migration of polymorphonuclear cells (PMN) to 

the injured tissue. This is a normal inflammatory reaction but in the presence of chitin 

and chitosan, there are no inflammatory symptoms, such as erythema, temperature 

elevation and abscess formation [158]. The intensity of complement [158] and 

macrophage [159] activation of chitin is less than chitosan; therefore, chitin is more 

immunomodulatory. 

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The Complex World of Polysaccharides 

 

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26. Blood cholesterol control 

Chitin and chitosan are among the candidates to battle obesity and hypercholesterolemia. It 

has been reported that they can reduce the amount of cholesterol in rats [160]. Several 

mechanisms have been proposed to explain this phenomenon. One is through electrostatic 

interaction between lipids and aminopolysaccharides [161]. Chitin binds to lipid 

(cholesterol) micelles and inhibits their absorption. Another proposed mechanism is 

increasing the excretion of bile acid by which the amount of fecal fat increases [162]. The 

hypocholesterolemic effect of chitosan has also been found in humans. The proposed 

cholesterol lowering mechanism of chitosan was that it combines bile acids in the digestive 

tract, and excretes them into the feces, thus decreasing the resorption of bile acids, so that 

the cholesterol pool in the body was decreased and the level of serum cholesterol 

consequently decreased [163]. 

27. Drug delivery carriers 

It is important for a drug delivery carrier to be efficiently removed after delivering drugs. In 

other words, it must not accumulate in the body nor must it be toxic [164].  

Chitosan offers several advantages, and these include its ability to control the release of 

active agents and avoid the use of hazardous organic solvents while fabricating particles 

since it is soluble in aqueous acidic solution. Chitosan in the form of colloidal structures 

can entrap macromolecules by various mechanisms. These associated macromolecules 

have been shown to transport through mucosa and epithelia more efficiently [165]. 

Cationic chitosan in combination with other natural polymers has been shown to 

enhance the drug encapsulation efficiency of liposomes via the layer-by-layer (L-b-L) 

self-assembly technique [166]. Nanoparticles made of chitosan in association with 

polyethylene oxide have been used as protein carrier [167]. Moreover, an oral delivery 

system has been developed by using chitosan and tripolyphosphate. In this system, 

micro- and nano-particles were entrapped in beads made from chitosan in solution of 

tripolyphosphate [168]. 

28. Food 

28.1. Chitosan films 

Edible films and coatings have received considerable attention in recent years because of 

their advantages including use as edible packaging materials over synthetic films. This 

could contribute to the reduction of environmental pollution. 

By functioning as barriers, such edible films and coatings can feasibly reduce the complexity 

and thus improve the recyclability of packaging materials, compared to the more traditional 

non-environmental friendly packaging materials, and may be able to substitute such 

synthetic polymer films [169]. 

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