Heparins including at least one covalent bond with biotin or a biotin derivative, method for preparing same and use thereof

A biotinylated heparin, comprising constituent polysaccharides, wherein the constituent polysaccharides have at their reducing ends a covalent bond to a group —(R1)i-Biot and correspond to the formula (I):

• in which:
• i is equal to 0 or 1,
• R1 represents a sequence of formula (a) or (b):
• in which j and k, which may be identical or different, are integers that may take any value from 1 to 10,
• Biot represents a biotin group or a biotin derivative,
• n represents an integer with a mean value of about 25 for a heparin with an average molecular mass of 15 000 Da,
• X represents H or SO3Na,
• Y represents COCH3 or SO3Na, and
• the wavy line denotes a bond located either below or above the plane of the pyranose ring to which it is attached,
• or the pharmaceutically acceptable salts thereof.