title: Thermo-responsive methylcellulose hydrogels as temporary substrate for cell sheet biofabrication.
abstract: Methylcellulose (MC), a water-soluble polymer derived from cellulose, was investigated as a possible temporary substrate having thermo-responsive properties favorable for cell culturing. MC-based hydrogels were prepared by a dispersion technique, mixing MC powder (2, 4, 6, 8, 10, 12 % w/v) with selected salts (sodium sulphate, Na2SO4), sodium phosphate, calcium chloride, or phosphate buffered saline, to evaluate the influence of different compositions on the thermo-responsive behavior. The inversion test was used to determine the gelation temperatures of the different hydrogel compositions; thermo-mechanical properties and thermo-reversibility of the MC hydrogels were investigated by rheological analysis. Gelation temperatures and rheological behavior depended on the MC concentration and type and concentration of salt used in hydrogel preparation. In vitro cytotoxicity tests, performed using L929 mouse fibroblasts, showed no toxic release from all the tested hydrogels. Among the investigated compositions, the hydrogel composed of 8 % w/v MC with 0.05 M Na2SO4 had a thermo-reversibility temperature at 37 °C. For that reason, this formulation was thus considered to verify the possibility of inducing in vitro spontaneous detachment of cells previously seeded on the hydrogel surface. A continuous cell layer (cell sheet) was allowed to grow and then detached from the hydrogel surface without the use of enzymes, thanks to the thermo-responsive behavior of the MC hydrogel. Immunofluorescence observation confirmed that the detached cell sheet was composed of closely interacting cells.
authors.affiliation: Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milan, MI, Italy.|INSTM, Consorzio Nazionale di Scienza e Tecnologia dei Materiali, Local Unit Politecnico di Milano, Milan, Italy.
authors.forename: Lina
authors.initials: L
authors.lastname: Altomare
authors.affiliation: Dipartimento di Scienze della Salute, Università del Piemonte Orientale (UPO), Via Solaroli 17, 28100, Novara, NO, Italy.|INSTM, Consorzio Nazionale di Scienza e Tecnologia dei Materiali, Local Unit Università del Piemonte Orientale, Novara, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cochis
authors.affiliation: Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milan, MI, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carletta
authors.affiliation: Dipartimento di Scienze della Salute, Università del Piemonte Orientale (UPO), Via Solaroli 17, 28100, Novara, NO, Italy. lia.rimondini@med.uniupo.it.|INSTM, Consorzio Nazionale di Scienza e Tecnologia dei Materiali, Local Unit Università del Piemonte Orientale, Novara, Italy. lia.rimondini@med.uniupo.it.
authors.forename: Lia
authors.initials: L
authors.lastname: Rimondini
authors.affiliation: Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano, Piazza L. Da Vinci 32, Milan, MI, Italy.|INSTM, Consorzio Nazionale di Scienza e Tecnologia dei Materiali, Local Unit Politecnico di Milano, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Farè
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000502:physiology*; D005347:Fibroblasts / Q000502:physiology*; D020100:Hydrogels / Q000737:chemistry*; D008747:Methylcellulose / Q000737:chemistry*; D051379:Mice; D041681:NIH 3T3 Cells; D012212:Rheology; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D008747:Methylcellulose