The present invention provides scaffolds that include a polymer and a cyclic peptide ligand. The peptide ligand increases the attachment of endothelial cells and/or progenitor cells to the scaffold. The present invention also provides engineered tissues that include the provided scaffolds. The present invention also provides coatings that include a coating polymer and a cyclic peptide ligand. The present invention also provides methods of improving endothelialization and vascularization of endothelial cells and/or progenitor cells for tissue regeneration in a subject and of repairing bone defects in a subject, by implanting a provided scaffold.