Inhibiting protein-protein interactions to achieve a therapeutically desired effect has been a goal in the field of drug discovery for decades. Recently, advances in peptidomimetics have led researches to the use of cyclized peptides to achieve this goal. Cyclization of linear peptides restricts the number of conformations of the peptide, increasing the peptide's affinity to binding to the desired target. Cyclization also stabilizes the peptide, allowing the peptide to be resistant to proteases. This study explores the optimization of solution phase synthesis of an important integrin-mediated cell adhesion cyclic peptide for the therapeutic inhibition of multiple myeloma, cHYD1. cHYD1 was originally synthesized via solid phase peptide synthesis, and the need for a scaled up synthesis version was needed after positive bioactivity results were obtained. Chapter 3 includes the molecular modeling exploration of a possible new mechanism to which cyclized peptides could work, in which, rather than a recognition and non-recognition strand being implemented, a specific directional face is used for protein-protein interaction. This was done with the implementation of an antagonistic cyclic peptide to replace human growth hormone in its interaction with the human growth hormone receptor, and the subsequent di-cyclic peptide agonist.