Peptides are an important class of molecules in contemporary drug research. They show very high binding specificity toward biological targets. They also participate in many essential biological processes. At the same time, natural peptides encounter major difficulties in medical applications. They often display poor chemical and biological stability. They usually have a very short half-life in circulation. They are also absorbed poorly when taken orally. These limitations restrict their direct clinical value as medicines. This study focuses on the chemical modification of bioactive peptides. Several common strategies are widely investigated. Cyclization of the peptide backbone produces a more rigid and stable structure. Lipidation of the peptide chain allows longer retention in the bloodstream and strengthens interactions with cell membranes. PEGylation and glycosylation both increase hydrophilicity and reduce rapid clearance from the body. Substitution of natural amino acids with D-amino acids improves resistance to enzymatic degradation and extends biological activity. Other methods also provide important support. Solid-phase peptide synthesis offers a practical and efficient route for preparing modified peptides on a large scale. Nanocarrier systems can protect peptide drugs during administration and assist in targeted delivery. In addition, artificial intelligence is being applied to predict structural features and to design new peptide molecules with higher efficiency.
Ang Li (Mon,) studied this question.