Method of purifying a biological material of interest in a sample using nanofiber ultrafiltration membranes operated in tangential flow filtration mode

1. Method of purifying a biological material of interest in a sample comprising:

a. providing a sample containing the biological material of interest having a molecular weight equal to or greater than 500 K Da, wherein the biological material of interest is selected from a therapeutic protein, a conjugated polysaccharide vaccine and a virus-like particle;

b. contacting the sample in tangential filtration (TFF) mode with an electrospun nanofiber membrane composition comprising nylon nanofibers having an average fiber diameter less than 15 nm, thereby resulting in a permeate and a retentate; and

c. collecting the retentate containing the biological material of interest, thereby purifying the biological material of interest.

2. The method of claim 1 , wherein the method results in an increase in the concentration of the biological material of interest.

3. The method of claim 1 , wherein the electrospun nanofiber composition exhibits a higher water permeability in TFF mode compared to a solution cast polymeric membrane.

4. The method of claim 1 , wherein the electrospun nanofiber membrane composition exhibits a higher flux in TFF mode compared to a solution cast polymeric membrane.

5. The method of claim 1 , wherein the collecting step comprises diafiltration.

6. The method of claim 1 , wherein the electrospun nanofiber membrane composition is made from Nylon-6.

7. The method of claim 1 , wherein the purified biological material of interest has a 90% yield or greater than 90% yield.

8. The method of claim 1 , wherein the electrospun nanofiber membrane composition is incorporated into a device suitable for TFF.

9. The method of claim 8 , wherein the device is a cassette or a spiral wound device.