title: Dual responsive nanostructured surfaces for biomedical applications.
abstract: In this paper, we describe the construction and characteristics of thermoresponsive, thin nanostructured films prepared by layer-by-layer sequential assembly of chitosan-graft-NIPAAm and alginate. FTIR and (1)H NMR spectra have confirmed the introduction of NIPAAm moieties onto the chitosan backbone. The LCST of the synthesized copolymer was found to be around 31-33 °C. The formation of the polyelectrolyte multilayers containing the copolymer and alginate was followed in situ by quartz crystal microbalance with dissipation monitoring technique and ex situ by UV-vis measurements. Our results revealed the linear increase of the multilayer film growth and the influence of the presence of salt. Moreover, AFM analysis has confirmed that PNIPAAm is able to reconform upon temperature swaps even when combined with other layers in a polyelectrolyte multilayer, demonstrating that the nanoassemblies are thermoresponsive. Preliminary results showed that, upon reducing culture temperature below PNIPAAm LCST, a gradual detachment of cell sheets from these PNIPAAm-based coatings has occurred.
authors.affiliation: 3B's Research Group - Biomaterials, Biodegradables, and Biomimetics, Department of Polymer Engineering, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Zona Industrial da Gandra, S. Cláudio do Barco, 4806-909 Caldas das Taipas Guimarães, Portugal.
authors.forename: Gabriela V
authors.initials: GV
authors.lastname: Martins
authors.forename: João F
authors.initials: JF
authors.lastname: Mano
authors.forename: Natália M
authors.initials: NM
authors.lastname: Alves
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000180:Acrylic Resins; D035843:Biomedical Research; D048271:Chitosan / Q000737:chemistry; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D013499:Surface Properties
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D008567:Membranes, Artificial; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D048271:Chitosan