# US 11,896,740 B2 · Water-soluble salt particle containing compositions and porous materials made therefrom > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,740 B2 - Document ID: US11896740B2 - Status: Granted - Kind: B2 - Application number: 16/760,355 - Filed: 2018-11-27 - Published: 2020-11-12 - Granted: 2024-02-13 - Earliest claimed: 2017-11-28 - Assignees: Northwestern University - Applicants: Northwestern University - Inventors: Adam E. Jakus; Ramille N. Shah; Nicholas R. Geisendorfer - Web page: https://patentgrep.com/patent/US11896740B2 ## CPC - A61L 27/56: Porous materials, {e.g. foams or sponges} - A61L 27/18: obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds - A61L 27/38: {containing added animal cells (organs or tissue containing native cells A61L27/36)} - A61L 27/3834: {Cells able to produce different cell types, e.g. hematopoietic stem cells, mesenchymal stem cells, marrow stromal cells, embryonic stem cells} - A61L 27/446: {with other specific inorganic fillers other than those covered by A61L27/443 or A61L27/46} - A61L 27/46: with phosphorus-containing inorganic fillers - B22F 10/18: by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF] - B22F 10/64: by thermal means (control of energy beam parameters for post heating B22F10/364) - B33Y 10/00: Processes of additive manufacturing - B33Y 40/20: Post-treatment, e.g. curing, coating or polishing - B33Y 70/00: Materials specially adapted for additive manufacturing - B33Y 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials - C08J 9/26: by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out - C08L 67/04: Polyesters derived from hydroxycarboxylic acids, e.g. lactones (C08L67/06 takes precedence) - A61L 2400/08: Methods for forming porous structures using a negative form which is filled and then removed by pyrolysis or dissolution - B22F 2998/10: Processes characterised by the sequence of their steps - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - C08J 2201/03: Extrusion of the foamable blend - C08J 2201/0444: Salts - C08J 2207/10: Medical applications, e.g. biocompatible scaffolds - C08J 2367/04: Polyesters derived from hydroxy carboxylic acids, e.g. lactones (C08J2367/06 takes precedence) - Y02E 60/50: Fuel cells - Y02P 10/25: Process efficiency - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Compositions for forming porous materials and three-dimensional objects, including fibers, films and coatings made from the materials are provided. Also provided are methods for forming the porous objects from the compositions. The compositions include a solvent, a polymer binder that is soluble in the solvent, and solid particles that are insoluble in the solvent. The solid particles include water-soluble salt particles that can be selectively dissolved from objects made from the compositions to render the resulting structures porous. ## Claims ### Claim 1 A method of forming a porous material system, the method comprising: using a viscous composition comprising a solids content to form a three-dimensional object, the viscous composition comprising a viscosity of 1 pascal second or more, and the solids content comprising: solid particles, at least some of which are water-soluble salt particles; and a polymer, the polymer acting as a binder for holding the solid particles together; wherein the solid particles are at least about 20 vol. % of the solids content; after the forming the three-dimensional object, hydrating the water-soluble salt particles by exposing the three-dimensional object to a salt-hydrating solution, wherein the water-soluble salt particles are hydratable salt particles that do not dissociate but undergo an increase in volume due to hydration in the salt-hydrating solution; and after the hydrating step, dissolving at least a portion of the hydrated, water-soluble salt particles in water, thereby forming the porous material system. ### Claim 2 (depends on 1) The method as in claim 1, wherein the using a viscous composition to form the three-dimensional object step is performed at room temperature. ### Claim 3 (depends on 1) The method as in claim 1, wherein the using a viscous composition to form the three-dimensional object step is performed at a temperature that is sufficiently low that, if the viscous composition comprises any bioactive factors, the bioactive factors will not undergo heat-induced degradation. ### Claim 4 (depends on 1) The method as in claim 1, wherein the using a viscous composition to form the three-dimensional object step further comprises: before the hydrating step, extruding the viscous composition through a nozzle to form an extruded composition, the extruded composition forming one or more fibers and drying the one or more fibers to form the three-dimensional object without any additional chemical, physical, or thermal processing. ### Claim 5 (depends on 4) The method as in claim 4, wherein the using a viscous composition to form the three-dimensional object, including extruding the viscous composition, is performed at temperatures that are sufficiently low that, if the viscous composition comprises any bioactive factors, the bioactive factors will not undergo heat-induced degradation. ### Claim 6 (depends on 4) The method as in claim 4, wherein extruding the viscous composition further comprises: a step of depositing the one or more extruded fibers in a printed layer. ### Claim 7 (depends on 6) The method as in claim 6, wherein the three-dimensional object comprises multiple, vertically stacked printed layers, by performing the depositing step repeatedly; wherein repeating the depositing step comprises forming subsequently printed layers on top of previously formed printed layers, and each of the subsequently printed layers bonding to at least one of the previously formed printed layer on which that subsequently printed layer is deposited. ### Claim 8 (depends on 1) The method as in claim 1, further comprising: after the dissolving step, drying the porous material system to remove moisture. ### Claim 9 (depends on 1) The method as in claim 1, further comprising: after the dissolving step, sintering the porous material system. ### Claim 10 (depends on 1) The method as in claim 1, further comprising: back-filling pores in the porous material system with a liquid solution or a hydrogel. ### Claim 11 (depends on 10) The method as in claim 10, wherein the liquid solution or the hydrogel has biological cells, bioactive factors, or a combination thereof, dispersed therein. ### Claim 12 (depends on 1) The method as in claim 1, further comprising: seeding the porous material system with biological cells and culturing the biological cell-seeded porous material system in a cell culture medium. ### Claim 13 (depends on 1) The method as in claim 1, the viscous composition further comprising bioactive factors. ### Claim 14 (depends on 1) The method as in claim 1, wherein the salt-hydrating solution is an alcohol-water solution. ### Claim 15 (depends on 1) The method as in claim 1, wherein the viscous composition comprises a viscosity of 1 to 100 pascal seconds. ### Claim 16 (depends on 1) The method as in claim 1, wherein the viscous composition comprises a viscosity of 25 to 100 pascal seconds. ### Claim 17 (depends on 1) The method as in claim 1, wherein the viscous composition comprises a viscosity of 25 to 50 pascal seconds. ### Claim 18 (depends on 1) The method as in claim 1, wherein the viscous composition comprises a viscosity of 1 to 5 pascal seconds. ### Claim 19 (depends on 1) The method as in claim 1, wherein the three-dimensional object is formed from the viscous composition using one or more of extrusion, 3D-printing, additive manufacturing, coating, molding, casting, and electrospinning. ### Claim 20 (depends on 1) The method as in claim 1, wherein the three-dimensional object is formed from the viscous composition by evaporation of a solvent of the viscous composition.