title: Injectable chitosan-based hydrogels for cartilage tissue engineering.
abstract: Water-soluble chitosan derivatives, chitosan-graft-glycolic acid (GA) and phloretic acid (PA) (CH-GA/PA), were designed to obtain biodegradable injectable chitosan hydrogels through enzymatic crosslinking with horseradish peroxidase (HRP) and H2O2. CH-GA/PA polymers were synthesized by first conjugating glycolic acid (GA) to native chitosan to render the polymer soluble at pH 7.4, and subsequent modification with phloretic acid (PA). The CH-GA43/PA10 with a degree of substitution (DS, defined as the number of substituted NH2 groups per 100 glucopyranose rings of chitosan) of GA of 43 and DS of PA of 10 showed a good solubility at pH values up to 10. Short gelation times (e.g. 10 s at a polymer concentration of 3 wt%), as recorded by the vial tilting method, were observed for the CH-GA43/PA10 hydrogels using HRP and H2O2. It was shown that these hydrogels can be readily degraded by lysozyme. In vitro culturing of chondrocytes in CH-GA43/PA10 hydrogels revealed that after 2 weeks the cells were viable and retained their round shape. These features indicate that CH-GA/PA hydrogels are promising as an artificial extracellular matrix for cartilage tissue engineering.
authors.affiliation: Department of Polymer Chemistry and Biomaterials, Institute for Biomedical Technology (BMTI), Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Jin
authors.forename: L S
authors.initials: LS
authors.lastname: Moreira Teixeira
authors.forename: P J
authors.initials: PJ
authors.lastname: Dijkstra
authors.forename: M
authors.initials: M
authors.lastname: Karperien
authors.forename: C A
authors.initials: CA
authors.lastname: van Blitterswijk
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Zhong
authors.forename: J
authors.initials: J
authors.lastname: Feijen
mesh_terms: D000818:Animals; D002356:Cartilage / Q000378:metabolism*; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D048271:Chitosan / Q000737:chemistry* / Q000378:metabolism*; D020100:Hydrogels / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007267:Injections; D015394:Molecular Structure; D009113:Muramidase / Q000378:metabolism; D012212:Rheology; D013997:Time Factors; D023822:Tissue Engineering; D014867:Water / Q000737:chemistry
chemical_list: D020100:Hydrogels; D014867:Water; D048271:Chitosan; D009113:Muramidase