title: Chitosan/agarose hydrogels: cooperative properties and microfluidic preparation.
abstract: The preparation of composite biopolymer hydrogels offers the capability to produce biocompatible and biodegradable materials with cooperative properties. In this paper, two natural polymers, namely, chitosan and agarose were employed to prepare composite hydrogels with dual pH and temperature properties. The elastic modulus of the composite hydrogels increased with agarose concentration reaching the value of 1 kPa for the chitosan/agarose gel with a 2% (w/v) concentration of agarose. In addition, composite gels exhibited a higher stability in acidic aqueous solutions, in comparison with agarose gels. The drug release properties of the composite hydrogels were tested by loading a model anticancer drug, 5-Fluorouracil, in the hydrogel interior. At pH=7.4, the cumulative release of 5-FU was ∼ 50% within 96 h and decreased to ∼ 33% at pH = 5.2, which was attributed to the different solubility of 5-FU as a function of pH. The preparation of composite microgels with controllable dimensions in the range from 42 to 18 μm and with narrow size distribution (polidispersity not exceeding 1.5%) was achieved by the microfluidic emulsification of an aqueous mixture of chitosan and agarose and subsequent gelation of the precursor droplets by cooling.
authors.affiliation: Institute of Polymer Science and Technology, The Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain; Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Zamora-Mora
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Diego
authors.initials: D
authors.lastname: Velasco
authors.affiliation: Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Hernández
authors.affiliation: Institute of Polymer Science and Technology, The Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain; Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Carmen
authors.initials: C
authors.lastname: Mijangos
authors.affiliation: Institute of Polymer Science and Technology, The Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain; Institute of Biomaterials & Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada. Electronic address: ekumache@chem.utoronto.ca.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Kumacheva
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry; D005472:Fluorouracil / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques; D012685:Sepharose / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D020100:Hydrogels; D012685:Sepharose; D048271:Chitosan; D005472:Fluorouracil
keywords: Agarose; Chitosan; Composite hydrogels; Drug release; Mechanical properties; Microfluidics