title: Chitosan membranes for tissue engineering: comparison of different crosslinkers.
abstract: Chitosan (CS), a derivative of the naturally occurring biopolymer chitin, is an attractive material for biomedical applications thanks to its biocompatibility, biodegradability, antibacterial properties and ability to enhance cell adhesion and growth compared to other biopolymers. However, the physical and mechanical stability of CS based materials in aqueous solutions is limited and crosslinking agents are required to increase CS performances in a biological environment. In this work, the effect of three highly-biocompatible crosslinkers as genipin (GP), γ-glycidoxypropyltrimethoxysilane (GPTMS), dibasic sodium phosphate (DSP) and a combination of GPTMS and DSP (GPTMS_DSP) on CS physicochemical, thermal, morphological, mechanical properties, swelling and degradation behavior was investigated. Infrared spectroscopy and thermogravimetric analyses confirmed the chemical reaction between CS and the different crosslinkers. CS wettability was enhanced when CS was DSP ionically crosslinked showing contact angle values of about 65° and exhibiting a higher swelling behavior compared to covalently crosslinked films. Moreover, all the crosslinking methods analyzed improved the stability of CS in aqueous media, showed model molecule permeation in time and increased the mechanical properties when compared with non-crosslinked films. The possibility to tailor the final properties of CS scaffolds through crosslinking is a key strategy in applying CS in different biomedical and tissue engineering applications. The obtained results reveal that the optimization of the crosslinking mechanism provides CS membrane properties required in different biomedical applications.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Ruini
authors.forename: C
authors.initials: C
authors.lastname: Tonda-Turo
authors.forename: V
authors.initials: V
authors.lastname: Chiono
authors.forename: G
authors.initials: G
authors.lastname: Ciardelli
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis*; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008567:Membranes, Artificial; D013314:Stress, Mechanical; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D008567:Membranes, Artificial; D048271:Chitosan