Immobilised biological entities
View Patent ↗There is described inter alia a device having a surface comprising a layered coating wherein the outer coating layer comprises a plurality of cationic hyperbranched polymer molecules characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 1,500 to 1,000,000 Da (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 and (iv) functional end groups, whereby one or more of said functional end groups have an anti-coagulant entity covalently attached thereto.
1. A device having a surface comprising a layered coating wherein the outer coating layer comprises a plurality of cationic hyperbranched polymer molecules characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 10,000 to 300,000 Da (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 and (iv) functional end groups, whereby one or more of said functional end groups have a heparin moiety covalently attached thereto, wherein said heparin moiety is single point covalently attached to the hyperbranched polymer molecule, and wherein the hyperbranched polymer is not a dendrimer.
2. A device according to claim 1 , wherein the heparin moieties are full length (native) heparin moieties.
3. A device according to claim 1 , wherein the heparin moieties are nitrous acid degraded heparin moieties.
4. A device according to claim 1 , wherein the heparin moieties are attached to the hyperbranched polymer molecules via the reducing end of the heparin moiety.
5. A device according to claim 1 , wherein the hyperbranched polymer is selected from polyamidoamine, polypropyleneimine, polyethyleneimine and polyamine polymers and copolymers comprising one or more of polyamidoamine, polypropyleneimine, polyethyleneimine and polyamine hyperbranched polymers.
6. A device according to claim 5 wherein the hyperbranched polymer is a polyamidoamine.
7. A device according to claim 5 wherein the hyperbranched polymer is a polyethyleneimine.
8. A device according to claim 1 , wherein the functional end groups are primary amine groups.
9. A device according to claim 1 , wherein the core moiety has a molecular weight of 50 to 130 Da.
10. A device according to claim 9 wherein the hyperbranched polymer has ethylenediamine as core moiety.
11. A device according to claim 1 , wherein the hyperbranched polymer has a molecular weight of 25,000 to 200,000 Da.
12. A device according to claim 1 , wherein the ratio of total molecular weight to core moiety molecular weight is at least 100:1.
13. A device according to claim 12 wherein the ratio of total molecular weight to core moiety molecular weight is between 200:1 and 5000:1 e.g. between 200:1 and 1600:1.
14. A device according to claim 1 , wherein the hyperbranched polymer molecule has a diameter of 5 to 30 nm.
15. A device according to claim 1 , wherein the hyperbranched polymer molecules are cross-linked to form aggregates of two or more hyperbranched polymer molecules.
16. A device according to claim 1 , wherein the heparin moieties are covalently attached to the hyperbranched polymer molecule via a linker comprising:
i. a secondary amine linkage;
ii. an amide linkage;
iii. a thioether linkage; or
vi. a 1,2,3-triazole linkage.
17. A device according to claim 1 , wherein the heparin moieties are covalently attached to functional end groups of the hyperbranched polymer molecule via a linker formed through a free radical initiated reaction.
18. A device according to claim 16 , wherein a spacer separates the linker from the hyperbranched polymer molecule and/or the heparin moiety.
19. A device according to claim 18 wherein the spacer comprises a PEG chain.
20. A device according to claim 1 , wherein the layered coating comprises one or more coating bilayers of cationic polymer and anionic polymer, the innermost layer preferably being a layer of cationic polymer.
21. A device according to claim 1 , wherein one or more of the layers of the layered coating other than the outer coating layer comprises a cationic hyperbranched polymer molecule characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 10,000 to 300,000 Da (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 and (iv) functional end groups which are optionally derivatised.
22. A device according to claim 20 wherein the anionic polymer is an anionic polysaccharide.
23. A device according to claim 20 wherein the anionic polymer is a functionalized hyperbranched cationic polymer with a net negative charge.
24. A device according to claim 1 , wherein hyperbranched polymer molecules of the outer coating layer are cross-linked to other hyperbranched polymer molecules of the outer coating layer or are cross-linked to molecules of an underlayer.
25. A device according to claim 1 which is a medical device.
26. A device according to claim 1 which is an analytical or separation device.
27. A device according to claim 1 wherein the layered coating of the device comprises one or more beneficial agents besides the heparin moieties.
28. A device according to claim 27 where said one or more beneficial agents are selected from drug molecules and lubricious agents.
29. A non-thrombogenic device which is obtainable by a process comprising:
(a) treating a device to present a surface coating comprising an outer coating layer comprising cationic hyperbranched polymer molecules characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 10,000 to 300,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 (e.g. at least 100:1) and bearing functional end groups, wherein the hyperbranched polymer is not a dendrimer;
(b) reacting at least one or more of said functional end groups with molecules of a heparin moiety which is functionalized to bear groups which are capable of reacting with the reactive functional groups on the hyperbranched cationic polymer;
thereby to attach the heparin moiety to the hyperbranched cationic polymer, wherein the heparin moiety is single point covalently attached to the hyperbranched polymer.
30. A non-thrombogenic device which is obtainable by a process comprising:
(a) treating a device to present a positively charged polymer surface layer; and
(b) associating with said polymer surface layer functionalized cationic hyperbranched polymer molecules characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 10,000 to 300,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 (e.g. at least 100:1) and bearing a multiplicity of negatively charged heparin moieties and wherein said functionalized hyperbranched cationic polymer has a net negative charge and is not a dendrimer;
or
(a) treating a device to present a negatively charged polymer surface layer; and
(b) associating with said polymer surface layer functionalized cationic hyperbranched polymer molecules characterized by having (i) a core moiety of molecular weight 14-1,000 Da (ii) a total molecular weight of 10,000 to 300,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 (e.g. at least 100:1) and bearing one or more negatively charged anti-coagulant entities such as heparin moieties and wherein said functionalized hyperbranched polymer has a net positive charge and is not a dendrimer, wherein the heparin moieties are single point covalently attached to the hyperbranched polymer.