Synthetic Polypeptide Design and Biomedical Applications

Synthetic polypeptides constitute a class of biomimetic polymers assembled from amino acid monomers, designed to emulate the structural and functional complexity of natural proteins. Advances in monomer synthesis, sequence control and catalytic methodologies have enabled precise tuning of chain length, architecture and secondary structure, notably α-helices and β-sheets. Contemporary strategies exploit novel catalysts, ambient-condition polymerisations and heterogeneous systems to overcome traditional limitations such as moisture sensitivity, slow kinetics and narrow functional group tolerance. In parallel, rapid progress in polypeptide-based materials has delivered bioresponsive hydrogels, targeted drug carriers, tissue scaffolds and enzyme-mimetic catalysts. These constructs leverage biodegradability, low immunogenicity and modularity to achieve controlled release, stimuli-responsiveness and high biocompatibility. The global significance of this field is underscored by its potential to transform drug delivery, regenerative medicine and diagnostics, offering scalable routes to tailor-made materials that interact predictably with biological systems.

Research from Nature Portfolio

Recent studies have introduced a nanoscale heterogeneous catalytic system in which metal–organic frameworks accelerate ring-opening polymerisation of N-carboxyanhydrides. This approach achieves rapid polypeptide synthesis with enhanced environmental tolerance, catalyst recyclability and seamless integration of polypeptide–MOF hybrids exhibiting combined porosity and biofunctionality. A complementary work has demonstrated a moisture-tolerant method for preparing unprotected α- and β-amino acid NCAs in air, using fast HCl scavengers to prevent side-reactions and enabling decagram-scale production of diverse monomers. The resultant NCAs yield water-soluble polypeptides suited to drug delivery and protein modification without conventional protection/deprotection steps. Further innovation has come from the use of crown ethers to catalyse NCA polymerisations initiated by simple amines. The cyclic ether dramatically accelerates kinetics in low-polarity solvents, suppressing side-reactions and affording well-defined polypeptides, including functionalised C-termini, under milder conditions than traditional catalysts.

Synthetic Polypeptide Design and Biomedical Applications publication trend

The graph below shows the total number of articles in synthetic polypeptide design and biomedical applications across all publications each year (not limited to Nature Index journals).

Technical terms

N-carboxyanhydride (NCA): A cyclic monomer derived from amino acids used for the ring-opening polymerisation to form polypeptides.

Ring-opening polymerisation (ROP): A chain-growth mechanism in which opening of a cyclic monomer leads to polymer formation, often employed for NCA monomers.

Metal–organic framework (MOF): A porous crystalline material composed of metal ions coordinated to organic ligands, used here as a heterogeneous catalyst for NCA polymerisation.

Organocatalyst: A small organic molecule that accelerates polymerisation reactions without metal residues, enabling cleaner synthesis of polypeptides.

Sulfur switch: A reversible redox or alkylation site in polypeptides that modulates conformation and properties in response to specific stimuli.

References

1. A nanoscale MOF-based heterogeneous catalytic system for the polymerization of N-carboxyanhydrides enables direct routes toward both polypeptides and related hybrid materials. Nature Communications (2023).
2. A moisture-tolerant route to unprotected α/β-amino acid N-carboxyanhydrides and facile synthesis of hyperbranched polypeptides. Nature Communications (2021).
3. Accelerated polymerization of N-carboxyanhydrides catalyzed by crown ether. Nature Communications (2021).
4. Sulfur Switches for Responsive Peptide Materials. Accounts of Chemical Research (2024).
5. Recent Advances in Poly(α-L-glutamic acid)-Based Nanomaterials for Drug Delivery. Biomolecules (2022).
6. Water-assisted and protein-initiated fast and controlled ring-opening polymerization of proline N-carboxyanhydride. National Science Review (2022).