Heparin has not been used as a macromolecule to prepare nanocarriers for drug delivery, even though it has advantageous structural features, such as a negatively charged structure and presence of specific binding domains of proteins. In this study, a nanogel of a Pluronic-conjugated heparin was prepared by direct dissolution to develop a versatile drug nanocarrier composed of heparin. The aqueous nanogel solution of the heparin-Pluronic (HP) conjugate, exhibited higher stability than the micelles and smaller hydrodynamic size than 100 nm. The drug encapsulation test demonstrated that the HP nanogel encapsulates efficiently both hydrophobic small molecules and proteins. The release profile of indomethacin (IMC) was almost zero-order without a burst due to the presence of heparin, which appears to be advantageous comparing to polymeric micelles. Circular dichroism (CD) and gel electrophoresis demonstrated that the stability of monoclonal antibodies (3D8 scFv) encapsulated into the HP nanogel had been maintained. Overall, the self-assembled HP nanogel may be a versatile and promising nanocarrier for a range of drugs in drug delivery applications.