Polymer-hydroxyapatite composite membranes
Provided herein is a chromatography media composed of a porous solid substrate (such as a membrane, metal, or metallic alloy) that is coated with hydroxyapatite (HA). Also provided is a chromatography media comprising a HA-coated substrate and uses thereof. Thus this disclosure provides a chromatography media composed of a porous solid substrate (such as a membrane, metal, or metallic alloy) that is coated with HA. Also provided is a chromatography media comprising a HA-coated substrate and uses thereof. Methods of preparing the HA-coated substrate are also provided.
1 . A hydroxyapatite (HA)-coated substrate made by a method comprising:
a) contacting a solid porous substrate comprising a hydroxyl group, amine group, quaternary amine group, aldehyde group, azide group, alkyne group, alkene group, phosphate group, sulfonate group, sulfate group, and/or carboxylic acid group with a solution comprising calcium ions, with the proviso that if a substrate comprises positively charged groups it is contacted with a phosphate containing solution and washed prior to contact with a solution comprising calcium ions;
b) washing the solid substrate contacted with the solution comprising calcium ions with a wash solution;
c) contacting the washed solid substrate of step b) with a solution comprising phosphate ions to form a solid substrate coated with a brushite form of calcium phosphate;
d) washing the solid substrate of step c) with a solution to form a brushite-coated substrate; and
e) optionally contacting the solid substrate of step d) with a solution comprising calcium ions and repeating steps b), c), and d); and
f) treating the brushite coated substrate with a base to form a HA-coated substrate, with the proviso that the substrate is not a particulate substrate;
wherein the solid porous substrate comprises:
i) cellulose, nitrocellulose, nylon, glass, methacrylate, polystyrene, polyethersulfone, or mixtures thereof; or
ii) glass, metal, a metallic alloy, nylon, polystyrene, cellulose, polyethersulfone, or nitrocellulose.
2 . A hydroxyapatite (HA)-coated substrate made by a method comprising:
a) contacting a solid porous substrate comprising positively charged groups with a solution comprising phosphate ions;
b) washing the solid porous substrate contacted with the solution comprising phosphate ions;
c) contacting the solid porous substrate of step b) with a solution comprising calcium ions;
d) washing the solid substrate contacted with the solution comprising calcium ions with a wash solution;
e) contacting the washed solid substrate of step b) with a solution comprising phosphate ions to form a solid substrate coated with a brushite form of calcium phosphate;
f) washing the solid substrate of step c) with a solution to form a brushite-coated substrate; and
g) optionally repeating steps c), d), e), and f); and
h) treating the brushite coated substrate with a base to form a HA-coated substrate, with the proviso that the substrate is not a particulate substrate.
3 . The HA-coated substrate of claim 2 , wherein when step 2g) is repeated, it is repeated Y times, where Y is any integer between 1 and 5000.
4 . The HA-coated substrate of claim 3 , wherein Y is an integer between 1 and 20.
5 . The HA-coated substrate of claim 1 , wherein when step 1e) is repeated, it is repeated Y times, where Y is any integer between 1 and 5000.
6 . The HA-coated substrate of claim 5 , wherein Y is an integer between 1 and 20.
7 . The HA-coated substrate of claim 1 , wherein the substrate comprises cellulose, nitrocellulose, nylon, glass, methacrylate, polystyrene, polyethersulfone, or mixtures thereof.
8 . The HA-coated substrate of claim 1 , wherein the substrate is macroporous.
9 . The HA-coated substrate of claim 1 , wherein the substrate has a pore diameter of about 1 to about 100 microns.
10 . The HA-coated substrate of claim 1 , wherein the substrate is washed with water.
11 . The HA-coated substrate of claim 1 , wherein the substrate comprises a sulfate group.
12 . The HA-coated substrate of claim 1 , wherein the substrate comprises a carboxylate group.
13 . The HA-coated substrate of claim 1 , wherein the substrate comprises a phosphate group.
14 . The HA-coated substrate of claim 1 , wherein the solution comprising phosphate ions is a sodium salt of phosphoric acid (Na 2 HPO 4 ).
15 . The HA-coated substrate of claim 1 , wherein the solution comprising calcium ions is CaCl 2 .
16 . The HA-coated substrate of claim 1 , wherein the calcium solution has a concentration between about 10 mM and about 1000 mM.
17 . The HA-coated substrate of claim 1 , wherein the phosphate solution has a concentration between about 10 mM to about 1000 mM.
18 . The HA-coated substrate of claim 1 , wherein brushite is converted to HA by treating the brushite-coated substrate with NaOH.
19 . The HA-coated substrate of claim 18 , wherein the brushite-coated substrate is treated with NaOH and heated to a temperature of about 55° C. to about 100° C.
20 . A chromatography material comprising a HA-coated substrate according to claim 1 .
21 . A method of performing chromatography, the method comprising:
contacting a sample comprising a target molecule to a HA-coated substrate according to claim 1 under conditions such that the target is not captured by the HA-coated substrate; and
collecting the target molecule from eluate that has flowed through the of HA-coated substrates.
22 . A method of performing chromatography, the method comprising:
contacting a sample comprising a target molecule to a HA-coated substrate according to claim 1 under conditions such that the target molecule is captured by the HA-coated substrate;
optionally washing the HA-coated substrates with a buffer; and
eluting and collecting the target molecule.
23 . A method of making a hydroxyapatite (HA)-coated substrate comprising:
a) contacting a solid porous substrate comprising a hydroxyl group, amine group, quaternary amine group, aldehyde group, azide group, alkyne group, alkene group, phosphate group, sulfonate group, sulfate group, and/or carboxylic acid group with a solution comprising calcium ions;
b) washing the solid substrate contacted with solution of calcium ions with a wash solution;
c) contacting the washed solid substrate of step b) with a solution comprising phosphate ions to form a solid substrate coated with a brushite form of calcium phosphate;
d) washing the solid substrate of step c) with a solution to form a brushite-coated substrate; and
e) optionally repeating steps b), c), and d); and
f) treating the brushite coated substrate with a base to form a HA-coated substrate, with the proviso that the substrate is not a particulate substrate.