Free radical degradation of chitosan with potassium persulfate

Hsu, Shih-Chang; Don, Trong‐Ming; Chiu, Wen‐Yen

doi:10.1016/s0141-3910(01)00205-1

Cited by 222 publications

(127 citation statements)

References 20 publications

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“…In present study, chitosan was depolymerized using potassium persulfate (KPS), which produced the LMWC in short time with homogenous product (16). A free radical degradation mechanism of chitosan with KPS was explained (30).…”

Section: Discussionmentioning

confidence: 99%

Development and In Vitro Characterization of Galactosylated Low Molecular Weight Chitosan Nanoparticles Bearing Doxorubicin

Jain

2010

AAPS PharmSciTech

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Abstract. The aim of the present research was to evaluate the potential of galactosylated low molecular weight chitosan (Gal-LMWC) nanoparticles bearing positively charged anticancer, doxorubicin (DOX) for hepatocyte targeting. The chitosan from crab shell was depolymerized, and the lactobionic acid was coupled with LMWC using carbodiimide chemistry. The depolymerized and galactosylated polymers were characterized. Two types of Gal-LMWC(s) with variable degree of substitution were employed to prepare the nanoparticles using ionotropic gelation with pentasodium tripolyphosphate anions. Factors affecting nanoparticles formation were discussed. The nanoparticles were characterized by transmission electron microscopy and photon correlation spectroscopy and found to be spherical in the size range 106-320 nm. Relatively higher percent DOX entrapment was obtained for Gal-LMWC(s) nanoparticles than for LMWC nanoparticles. A further increase in drug entrapment was found with nanoparticles prepared by Gal-LMWC with higher degree of substitution. A hypothesis which correlates the ionic concentration of DOX in nanoparticles preparation medium and percent DOX entrapment in cationic polymer has been proposed to explain the enhanced DOX entrapment. In-vitro drug release study demonstrated an initial burst release followed by a sustained release. The targeting potential of the prepared nanoparticles was assessed by in vitro cytotoxicity study using the human hepatocellular carcinoma cell line (HepG 2 ) expressing the ASGP receptors on their surfaces. The enthusiastic results showed the feasibility of Gal-LMWC(s) to entrap the cationic DOX and targeting potential of developed Gal-LMWC(s) nanoparticles to HepG 2 cell line.

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Section: Discussionmentioning

confidence: 99%

Development and In Vitro Characterization of Galactosylated Low Molecular Weight Chitosan Nanoparticles Bearing Doxorubicin

Jain

2010

AAPS PharmSciTech

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“…Enzymatically, chitosan can be degraded by enzymes able to hydrolyse glucosamine-glucosamine, glucosamine-N-acetyl-glucosamine and N-acetyl-glucosamine-N-acetyl-glucosamine linkages [83]. Even though depolymerisation through oxidationreduction reaction [84] and free radical degradation [85] of chitosan have been reported these are unlikely to play a significant role in the in vivo degradation.…”

Section: Biodegradabilitymentioning

confidence: 99%

Is Chitosan a New Panacea? Areas of Application

Castro¹,

Paulín²

2012

The Complex World of Polysaccharides

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Chitin is a big molecule composed of -beta-1,4-N-acetylglucosamine (GlcNAc) monomers. There are three forms of chitin: , , and chitin. The -form, is mainly obtained from crab and shrimp. Both and chitin/chitosan are commercially available [5]. Sources of chitinIn the book "Chitin" published by Muzarelli in 1977, we can find a complete list of organisms that contain chitin: Fungi, Algae, Cnidaria (jellyfish), Aschelminthes (round worm), Entoprocta, Bryozoa (Moss or lace animals, Phoronida (Horseshoe worms), Brachiopoda(Lamp shells), Echiruda, Annelida (Segmented worms), Mollusca, Arthropoda and Ponogophora [6]). Herring, P.J in 1979 wrote that chitin is the main component of arthropod exoskeletons, tendons, and the linings of their respiratory, excretory, and digestive systems, as well as insects external structure and some fungi. It is also found in the reflective material (iridophores) of both epidermis and eyes of arthropods and cephalopods (phylum: Mollusca) and the epidermal cuticle of the vertebrate Paralipophrys trigloides (fish) is also chitinous [7,8]. The main commercial sources of chitin are the shell wastes of shrimp, lobsters, crabs and krill. There are three forms of chitin: , , and chitin. The -form, is composed of alternating antiparallel polysaccharide strands and is mainly obtained from crab and shrimp. -Chitin is by far the most abundant; it occurs in fungal and yeast cell walls, krill, lobster and crab tendons and shells, shrimp shells, and insect cuticle. The rarer -chitin is composed of parallel strands of polysaccharides, is found in association with proteins in squid pens [9,10] and in the tubes synthesized by pogonophoran and vestimetiferan worms [11,12]. It also occurs in aphrodite chaetae [13] as well as in the lorica, built by some seaweeds or protozoa [14,15,16]. And 2 parallel chains alternating with an antiparallel strand constitute gamma chitin and are found in fungi [15].

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“…Degradation of chitosan may be achieved by chemical (acid) hydrolysis (Qin et al 2002, Jia and Shen 2002, Hsu et al 2002 or enzymatic hydrolysis (Qin et al, 2003, Shin-ya et al, 2001) Although hydolysis of chitosan with acids is fast and less expensive, the chemical structure of residues is easily damaged. The use of enzyme for degradation is generally more suitable as the course of the hydrolysis process and the product distribution are easier to control.…”

Section: Characterization 241 Measurement Of Viscositymentioning

confidence: 99%