title: Microfluidic Foaming: A Powerful Tool for Tailoring the Morphological and Permeability Properties of Sponge-like Biopolymeric Scaffolds.
abstract: Ordered porous polymeric materials can be engineered to present highly ordered pore arrays and uniform and tunable pore size. These features prompted a number of applications in tissue engineering, generation of meta materials, and separation and purification of biomolecules and cells. Designing new and efficient vistas for the generation of ordered porous materials is an active area of research. Here we investigate the potential of microfluidic foaming within a flow-focusing (FF) geometry in producing 3D regular sponge-like polymeric matrices with tailored morphological and permeability properties. The challenge in using microfluidic systems for the generation of polymeric foams is in the high viscosity of the continuous phase. We demonstrate that as the viscosity of the aqueous solution increases, the accessible range of foam bubble fraction (Φb) and bubble diameter (Db) inside the microfluidic chip tend to narrow progressively. This effect limits the accessible range of geometric properties of the resulting materials. We further show that this problem can be rationally tackled by appropriate choice of the concentration of the polymer. We demonstrate that via such optimization, the microfluidic assisted synthesis of porous materials becomes a facile and versatile tool for generation of porous materials with a wide range of pore size and pore volume. Moreover, we demonstrate that the size of interconnects among pores-for a given value of the gas fraction-can be tailored through the variation of surfactant concentration. This, in turn, affects the permeability of the materials, a factor of key importance in flow-through applications and in tissue engineering.
authors.affiliation: Department of Chemistry, Sapienza University of Rome , 00185 Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Costantini
authors.affiliation: Department of Chemistry, Sapienza University of Rome , 00185 Rome, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Colosi
authors.affiliation: Faculty of Materials Science and Engineering, Warsaw University of Technology , 02507 Warsaw, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Jaroszewicz
authors.affiliation: Department of Chemistry, Sapienza University of Rome , 00185 Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Tosato
authors.affiliation: Faculty of Materials Science and Engineering, Warsaw University of Technology , 02507 Warsaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Święszkowski
authors.affiliation: Department of Chemistry, Sapienza University of Rome , 00185 Rome, Italy.
authors.forename: Mariella
authors.initials: M
authors.lastname: Dentini
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences , 01224 Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Garstecki
authors.affiliation: Department of Chemistry, Sapienza University of Rome , 00185 Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbetta
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D056656:Lab-On-A-Chip Devices; D010539:Permeability / Q000187:drug effects; D011108:Polymers / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014783:Viscosity / Q000187:drug effects
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D013501:Surface-Active Agents
keywords: alginate; microcomputed X-ray tomography; microfluidic foaming; ordered porous structure; scaffolds; solution viscosity