Investigation of cyclic peptides as drug delivery systems for the delivery of the anti-tuberculosis drug pyrazinamide.

One of the important goals of drug delivery in the treatment of diseases is to effectively deliver drugs to deep and inaccessible areas of tissues. In recent years, cyclic peptides (CPs) have been used as drug delivery systems due to their high affinity for their targets, stability against degradation, and low toxicity. In this study, the interaction of the anti-tuberculosis drug pyrazinamide (PY) with cyclic decapeptides of glycine, alanine, and serine and their binary alternating sequences was investigated at the M06-2X/6-31G(d,p) level of theory in the gas phase. Interaction energies, structural parameters, topological properties, and RDG, ELF, and IGM analyses were used to assess the strength of interactions in the complexes. The electronic properties of cyclic peptides were investigated and compared before and after the complexation process. Based on the findings of this study, cyclic peptides based on binary alternating sequences have a higher tendency to interact with the pyrazinamide molecule. Therefore, the use of a combination of amino acids in cyclic peptides allowed for the rational design of a new material with more favorable properties. These findings provide insights into the development of more effective drugs using cyclic peptides.