Method of forming polysaccharide structures

A process of forming a porous agarose coating on a porous substrate comprising the steps of:

• a) providing a mixture including agarose, water, and an effective amount of a gel-inhibiting agent selected from the group consisting of zinc chloride, lithium chloride, sodium iodide, potassium iodide and mixtures thereof in concentrations greater than about 15% by weight of the mixture,
• b) heating the mixture to a temperature above the melting point of the agarose, for a time sufficient to dissolve the agarose in the water forming an agarose solution,
• c) reducing the temperature of the agarose solution to about room temperature wherein the agarose solution is stable at a temperature of about 20° C.,
• d) providing a porous substrate,
• e) wetting the porous substrate with the room temperature stable agarose solution so as to coat all surfaces of the porous substrate,
• f) evaporating the water from the agarose solution on the porous substrate to form a dry porous agarose coating on the surface of the porous substrate,
• g) subjecting the dry porous agarose coating on the substrate to a gelling agent selected from the group consisting of acetone, methanol, ethanol, propanol and blends thereof, to remove the gel-inhibiting agent from the agarose coating on the substrate, and
• h) rinsing the porous agarose coated substrate in water to remove the gelling agent.

A method of forming porous agarose beads comprising the steps of:

• a) providing a mixture of agarose and water,
• b) heating the mixture to a temperature above the melting point of the agarose, for a time sufficient to dissolve the agarose in the water to form an agarose solution,
• c) reducing the temperature of the agarose solution to about room temperature,
• d) adding to the agarose solution an effective amount of a gel-inhibiting agent selected from the group consisting of zinc chloride, lithium chloride, sodium iodide, potassium iodide and mixture thereof in concentrations greater than about 15% by weight of the solution, to form an agarose solution stable at a temperature of about 20° C.,
• e) adding to the agarose solution a fluorosurfactant,
• f) providing a gelling agent bath wherein the gelling agent is elected from the group consisting of acetone, alcohols and blends thereof,
• g) applying the agarose solution from step (e) drop wise into the gelling agent bath, thereby forming porous agarose beads, and
• h) rinsing the porous agarose beads in water to remove the gelling agent and the fluorosurfactant.

A method of forming a crosslinked agarose coating on a porous substrate comprising the steps of:

• a) providing a mixture of agarose, water, and an effective amount of a gel-inhibiting agent selected from the group consisting of zinc chloride, lithium chloride, sodium iodide, potassium iodide and mixture thereof in concentrations greater than about 15% by weight of the mixture,
• b) heating the mixture to a temperature above the melting point of the agarose, for a time sufficient to dissolve the agarose in the water forming an agarose solution,
• c) reducing the temperature of the agarose solution to about room temperature to form a room temperature stable agarose solution stable at a temperature of about 20° C.,
• d) adding a crosslinker selected from the group consisting of epichlorohydrin, multifunctional epoxy compounds, multifunctional halides, ethylene glycol diglycidyl ether, formaldehyde, gluteraldehyde, multifunctional aldehydes, bis(2-hydroxy ethyl)sulfone, dimethyldichloro-silane, dimethylolurea, dimethylol ethylene urea, diisocyanates, polyisocyanates, and 1,4-butanediol diglycidyl ether, to the room temperature stable agarose solution,
• e) providing a porous substrate,
• f) wetting the porous substrate with the room temperature stable agarose solution so as to coat all surfaces of the porous- substrate,
• g) crosslinking under heat the crosslinker and the agarose in the solution coating the substrate resulting in a crosslinked agarose coating on the porous substrate,
• h) evaporating the water from the crosslinked agarose coating to form a dry crosslinked agarose coating on the porous substrate,
• i) subjecting the dry crosslinked agarose coating on the coated substrate to a gelling agent selected from the group consisting of acetone, alcohols and blends thereof, to remove the gel-inhibiting agent from the crosslinked agarose coating on the substrate, and
• j) rinsing the crosslinked agarose coated substrate in water to remove the gelling agent.

A method of forming a crosslinked agarose coating on a porous substrate comprising the steps of:

• a) providing a mixture of agarose, water, and an effective amount of a gel-inhibiting agent selected from the group consisting of zinc chloride, lithium chloride, sodium iodide, potassium iodide and mixture thereof in concentrations greater than about 15% by weight of the mixture,
• b) heating the solution to a temperature above the melting point of the agarose, for a time sufficient to dissolve the agarose in the water forming an agarose solution,
• c) reducing the temperature of the agarose solution to about room temperature to form a room temperature stable agarose solution stable at a temperature of about 20° C.,
• d) adding to the agarose solution a fluorosurfactant having a concentration about 0.001% to about 10% by total weight of the aqueous solution,
• e) adding a crosslinker selected from the group consisting of epichlorohydrin, multifunctional epoxy compounds, multifunctional halides, ethylene glycol diglycidyl ether, formaldehyde, gluteraldehyde, multifunctional aldehydes, bis(2-hydroxy ethyl)sulfone, dimethyldichloro-silane, dimethylolurea, dimethylol ethylene urea, diisocyanates, polyisocyanates, and 1,4-butanediol diglycidyl ether to the room temperature stable agarose solution,
• f) providing a porous substrate,
• g) wetting the porous substrate with the room temperature stable agarose solution so as to coat all surfaces of the porous substrate,
• h) crosslinking under heat the crosslinker-room temperature stable agarose solution coating the substrate,
• i) evaporating the water from the crosslinked agarose coating to form a dry crosslinked agarose coating on the surface of the porous substrate,
• j) subjecting the dry crosslinked agarose coating on the coated substrate to a gelling agent selected from the group consisting of water, acetone, methanol, ethanol, propanol and blends thereof, to remove the gel-inhibiting agent from the crosslinked agarose coating on the substrate, and
• k) rinsing the crosslinked agarose coated substrate in water to remove the gelling agent.

A method of forming porous agarose beads comprising the steps of:

• a) providing agarose, water, and an effective amount of a gel-inhibiting agent selected from the group consisting of urea, guanidinium salts, zinc chloride, lithium chloride, sodium iodide, potassium iodide and mixtures thereof,
• b) adding the agarose, the water and the effective amount of the gel-inhibiting agent together to form a mixture such that the agarose is present from about 0.1% to about 20% by weight of the mixture, and the gel-inhibiting agent is present in concentrations greater than about 15% by weight of the solution,
• c) heating the mixture to a temperature above the melting point of the agarose for a time sufficient to dissolve the agarose and the gel-inhibiting agent into the water to form a first agarose solution,
• d) reducing the temperature of the a first agarose solution to about room temperature wherein the agarose solution is stable at a temperature of about 20° C.,
• e) adding to the first agarose solution a fluorosurfactant,
• f) providing a gelling agent bath wherein the gelling agent is selected from the group consisting of acetone, alcohols and blends thereof,
• g) applying the first agarose solution from step (e) drop wise into the gelling agent bath thereby forming porous agarose beads, and
• h) rinsing the porous agarose beads in water to remove the gelling agent and the fluorosurfactant.

A method of forming porous agarose beads comprising the steps of:

• a) providing agarose and water;
• b) forming a mixture from the agarose and water;
• c) heating the mixture to a temperature at or above the melting temperature of the agarose to dissolve the agarose in the water;
• d) cooling the first agarose solution to form a gel;
• e) adding to the gel a gel-inhibiting agent selected from urea, guanidinium salts, zinc chloride, lithium chloride, sodium iodide, and potassium iodide in concentrations greater than about 15% by total weight of the gel;
• f) heating the gel and gel-inhibiting agent to form a second agarose solution;
• g) reducing the temperature of the second agarose solution to about room temperature wherein the second agarose solution is stable at a temperature of about 20° C., and the agarose is present from about 0.1% to about 20% by weight of the second agarose solution;
• h) adding to the room temperature second agarose solution an anionic surfactant;
• i) providing a gelling agent bath wherein the gelling agent is elected from the group consisting of acetone, alcohols and blends thereof;
• j) applying the room temperature stable second agarose solution from step (g) drop wise into the gelling agent bath thereby forming porous agarose beads, and
• k) rinsing the porous agarose beads in water to remove the gelling agent and the fluorosurfactant.

A method of forming a porous agarose coating on a porous substrate comprising the steps of:

• a) providing agarose, water, a fluorosurfactant, and a gel-inhibiting agent selected from urea, guanidinium salts, zinc chloride, lithium chloride, sodium iodide, and potassium iodide, wherein the concentration of the gel-inhibiting agent is greater than about 15% by total weight;
• b) forming a mixture of agarose and the water;
• c) heating the mixture to a temperature at or above the melting temperature of the agarose to form a first agarose solution;
• d) cooling the first agarose solution to form a gel;
• e) adding the gel-inhibiting agent to the gel;
• f) heating the gel and gel-inhibiting agent to form a second agarose solution;
• g) reducing the temperature of the second agarose solution to about room temperature wherein the second agarose solution is stable at a temperature of about 20° C., and the agarose is present from about 0.1% to about 20% by weight of the second agarose solution;
• h) adding the fluorosurfactant to the second agarose solution;
• i) providing a porous substrate;
• j) coating the porous substrate with the second agarose solution resulting in a porous agarose coating on the porous substrate;
• and
• k) subjecting the porous agarose coating on the porous substrate to a gelling agent selected from the group consisting of acetone, methanol, ethanol, propanol and blends thereof, to remove the gel-inhibiting agent from the porous agarose coating on the substrate.