The present invention provides a variety of isolated peptides and peptidomimetics, which can be useful, for example, in constructing the conjugates of the invention or, where the peptide itself has biological activity, in unconjugated form as a therapeutic for treating any of a variety of cardiovascular diseases as described below. Thus, the present invention provides an isolated peptide or peptidomimetic which has a length of less than 60 residues and includes the amino acid sequence CRPPR (SEQ ID NO: 1) or a peptidomimetic thereof. The invention further provides an isolated peptide or peptidomimetic which has a length of less than 60 residues and includes the amino acid sequence CARPAR (SEQ ID NO: 5) or a peptidomimetic thereof, or amino acid sequence CPKRPR (SEQ ID NO: 6) or a peptidomimetic thereof.