title: Microfluidics-assisted generation of stimuli-responsive hydrogels based on alginates incorporated with thermo-responsive and amphiphilic polymers as novel biomaterials.
abstract: We used a droplet-based microfluidics technique to produce monodisperse responsive alginate-block-polyetheramine copolymer microgels. The polyetheramine group (PEA), corresponding to a propylene oxide /ethylene oxide ratio (PO/EO) of 29/6 (Jeffamine(®) M2005), was condensed, via the amine link, to alginates with various mannuronic/guluronic acids ratios and using two alginate:jeffamine mass ratios. The size of the grafted-alginate microgels varied from 60 to 80 μm depending on the type of alginate used and the degree of substitution. The droplet-based microfluidics technique offered exquisite control of both the dimension and physical chemical properties of the grafted-alginate microgels. These microgels were therefore comparable to isolated grafted-alginate chains in retaining both their amphiphilic and thermo-sensitive properties. Amphiphilicity was demonstrated at the oil-water interface where grafted-alginate microgels were found to decrease interfacial tension by ∼ 50%. The thermo-sensitivity of microgels was clearly demonstrated and a 10 to 20% reduction in size between was evidenced on increasing the temperature above the lower critical solution temperature (TLCST) of Jeffamine. In addition, the reversibility of thermo-sensitivity was demonstrated by studying the oil-water affinity of microgels with temperature after Congo red labeling. Finally, droplet-based microfluidics was found to be a good and promising tool for generating responsive biobased hydrogels for drug delivery applications and potential new colloidal stabilizers for dispersed systems such as Pickering emulsions.
authors: Université de Rouen Laboratoire Polymères, Biopolymères, Surfaces, CNRS UMR 6270, INC3M FR3038, Bd de Broglie, F-76821 Mont Saint Aignan, France.
authors: C
authors: C
authors: Karakasyan
authors: INRA, UR1268 Biopolymères Interactions Assemblages, F-44300 Nantes Cedex, France.
authors: J
authors: J
authors: Mathos
authors: Laboratoires Brothier, Centre de Recherche & Développement, Z.A. des Roches, B.P. 26, F-49590 Fontevraud L'abbaye, France.
authors: S
authors: S
authors: Lack
authors: INRA, UR1268 Biopolymères Interactions Assemblages, F-44300 Nantes Cedex, France.
authors: J
authors: J
authors: Davy
authors: INRA, UR1268 Biopolymères Interactions Assemblages, F-44300 Nantes Cedex, France.
authors: M
authors: M
authors: Marquis
authors: INRA, UR1268 Biopolymères Interactions Assemblages, F-44300 Nantes Cedex, France. Electronic address: denis.renard@nantes.inra.fr.
authors: D
authors: D
authors: Renard
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry; D005027:Ethylene Oxide / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D044085:Microfluidics; D009821:Oils / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013500:Surface Tension; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D004852:Epoxy Compounds; D020100:Hydrogels; D009821:Oils; D011108:Polymers; D014867:Water; D005027:Ethylene Oxide; C009068:propylene oxide
keywords: Amphiphilic; Grafted-alginate; Microfluidics; Microgel; Thermo-sensitive