Immobilised biological entities

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 1,500 to 1,000,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 and bearing functional end groups;
• (b) reacting at least one or more of said functional end groups with molecules of an anti-coagulant entity 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 anti-coagulant entity to the hyperbranched cationic polymer, wherein the hyperbranched polymer is a PAMAM dendrimer, wherein the coating comprises one or more coating bilayers of cationic polymer and anionic polymer, the innermost layer being a layer of cationic polymer, wherein one or more of the layers of the layered coating other than the outer coating layer comprises a cationic hyperbranched polymer molecule which is a PAMAM dendrimer 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 which are optionally derivatised.

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 1,500 to 1,000,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 and bearing a multiplicity of negatively charged anti-coagulant entities such as heparin moieties and wherein said functionalized hyperbranched cationic polymer has a net negative charge and is a PAMAM dendrimer, wherein the coating comprises one or more coating bilayers of cationic polymer and anionic polymer, the innermost layer being a layer of cationic polymer, wherein one or more of the layers of the layered coating other than the outer coating layer comprises a cationic hyperbranched polymer molecule which is a PAMAM dendrimer 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 which are optionally derivatised;
• 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 1,500 to 1,000,000 Da and (iii) a ratio of total molecular weight to core moiety molecular weight of at least 80:1 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 a PAMAM dendrimer, wherein the coating comprises one or more coating bilayers of cationic polymer and anionic polymer, the innermost layer being a layer of cationic polymer, wherein one or more of the layers of the layered coating other than the outer coating layer comprises a cationic hyperbranched polymer molecule which is a PAMAM dendrimer 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 which are optionally derivatised.