Process for recovering viral products using functionalised chromatography media

1. A process for recovering a full viral product from a composition comprising said full viral product and an empty viral product, which process comprises:

a) contacting the composition with a functionalised chromatography medium, wherein the composition has a dissolved salt concentration such that an electrical conductivity is below 10 mS/cm;

b) washing the functionalised chromatography medium with a liquid phase of low ionic concentration corresponding to the electric conductivity of a); and

c) selectively eluting the full viral product from and the empty viral product by contacting the functionalised chromatography medium with a liquid phase of increasing ionic strength;

wherein the full viral product is an Adenovirus or an Adeno-associated virus or corresponding viral particle containing one or more polynucleotides, and wherein the empty viral product is an Adenovirus or an Adeno-associated virus or corresponding viral particle substantially devoid of polynucleotides; and

wherein the functionalised chromatography medium comprises one or more non-woven non-grafted cellulose nanofibers having a density of 600 μmol to 1000 μmol trimethylammonium ligand groups per gram of functionalised chromatography medium.

2. The process according to claim 1 , wherein the full viral product comprises a plurality of viruses, virus particles, viral cores, membrane-stripped viruses, viral cores with outer membrane(s) removed and/or capsids removed, or proviruses, each of which is capable of infecting a cell.

3. The process according to claim 1 , wherein the full viral product comprises a plurality of viral vectors each containing one or more transgenic polynucleotides.

4. The process according to claim 1 , wherein the empty viral product comprises a plurality of viruses, virus particles/virions, virus-like particles, viral cores, membrane-stripped viruses, viral cores with outer membrane(s) removed and/or capsids removed or proviruses, each of which is incapable of infecting a cell.

5. The process according to claim 1 , wherein the empty viral product comprises a plurality of viruses, virus particles/virions, virus-like particles viral cores, membrane-stripped viruses, viral cores with outer membrane(s) removed and/or capsids removed or proviruses, each of which lacks a complete viral genome.

6. The process according to claim 1 , wherein the functionalised chromatography medium is suitable for use in a chromatography method chosen from the group consisting of ion exchange, hydrophobic interaction and mixed mode methods.

7. The process according to claim 1 , wherein the functionalised chromatography medium has a dynamic binding capacity of up to 50 mg/mL (10% breakthrough).

8. The process according to claim 1 , wherein the functionalised chromatography medium is in the form of a membrane or sheet.

9. The process according to claim 1 , wherein the functionalised chromatography medium is in the form of a membrane or sheet and the composition is passed through a holder comprising one or more said membranes or sheets and optionally one or more frits or other spacer materials.

10. The process according to claim 9 , wherein the composition is passed through the holder such that the path length through said one or more membranes or sheets is less than 2 mm, or the total path length through membranes, sheets, frits and other spacer materials is less than 50 mm.

11. The process according to claim 1 , wherein the composition is contacted with the functionalised chromatography medium for a period of time of one minute or less.

12. The process according to claim 1 , wherein the one or more polynucleotides are one or more nucleic acids chosen from DNA and RNA, including siRNA.

13. The process according to claim 1 , wherein the empty viral product is collected as a secondary product.