title: Pharmacokinetics and biodegradation mechanisms of a versatile carboxymethyl derivative of chitosan in rats: in vivo and in vitro evaluation.
abstract: Carboxymethyl chitosan (CM-chitosan), which is a water-soluble derivative of chitosan, has attracted much attention as a new biomedical material. The safety study of this material was persuasive for its potential application. The present study was conducted to assess the tissue distribution, pharmacokinetics, biodegradation mechanism, and excretion of CM-chitosan in rats. After the rats were intraperitoneally injected at the dose of 50 mg/kg, the fluorescein isothiocyanate (FITC)-labeled CM-chitosan was absorbed rapidly and distributed to different organs, including liver, spleen, and kidney. The highest level of CM-chitosan was found in liver. It was at the level of 1.6 +/- 0.6 mg/liver and made up approximately 10-22% of the total injected FTC-CM-chitosan. Urinary excretion was the predominant way of excretion of FITC-labeled CM-chitosan, and 85% of the dose was excreted in urine over the period of 11 days. The molecular weights of body distributed FTC-CM-chitosan and urinary excreted FTC-CM-chitosan were analyzed by gel chromatography. The results indicated that the FTC-CM-chitosan was degraded in abdominal dropsy. The absorbed CM-chitosan forms were found with a relatively high molecular weight (approximately 300 kDa), whereas the molecular weight of the urinary excreted FTC-CM-chitosan was less than 45 kDa. In vitro research revealed that the CM-Chi was also degradable in plasma and homogenate of liver. The CM-chitosan with a molecular weight of approximately 800k was thoroughly degraded to a small molecule after it was incubated in homogenate of liver at 37 degrees C for 24 h. The results suggested that the liver plays a central role in biodegradation of CM-chitosan. The excellent biodegradability of CM-chitosan could potentially contribute to the clinical applications. The results also provide important clues for further modification of CM-chitosan as the postsurgical and other biomedical materials.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Dong
authors.forename: Baoqing
authors.initials: B
authors.lastname: Han
authors.forename: Yilin
authors.initials: Y
authors.lastname: Feng
authors.forename: Fulai
authors.initials: F
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Chang
authors.forename: Huiping
authors.initials: H
authors.lastname: Jiang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Tang
authors.forename: Wanshun
authors.initials: W
authors.lastname: Liu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000493:pharmacokinetics*; D048271:Chitosan / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics / Q000652:urine; D016650:Fluorescein-5-isothiocyanate; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008970:Molecular Weight; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D013154:Spleen / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D001672:Biocompatible Materials; C514968:carboxymethyl-chitosan; D048271:Chitosan; D016650:Fluorescein-5-isothiocyanate