Cell-penetrating peptides: design, synthesis, and applications

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Delivery Systems

Background:

• Cell-penetrating peptides (CPPs) possess intrinsic properties for delivering therapeutic molecules like nucleic acids, drugs, and imaging agents into cells and tissues.
• CPPs offer a nontoxic delivery mechanism, positioning them as potential components for future pharmaceuticals and disease diagnostic agents.
• These peptides are easily synthesized, functionalized, and characterized, enabling the delivery of diverse bioactive cargos.

Purpose of the Study:

• To explore the potential of cell-penetrating peptides (CPPs) as versatile vectors for therapeutic and diagnostic agent delivery.
• To highlight the importance of CPP functionalization for achieving targeted delivery of various cargos, from small molecules to large nucleic acids.
• To emphasize the critical role of both cargo and CPP design in developing effective systemic delivery systems.

Main Methods:

• Review of existing literature on cell-penetrating peptide (CPP) applications in drug and nucleic acid delivery.
• Analysis of CPP mechanisms, primarily endocytosis, for intracellular cargo transport.
• Discussion of strategies for CPP functionalization and chemical modification to enhance targeting specificity.

Main Results:

• CPPs facilitate the delivery of covalently or noncovalently conjugated cargos (e.g., plasmid DNA, drugs) into cells.
• Delivery is primarily achieved via endocytosis, leading to gene expression, gene silencing, or tumor targeting.
• CPPs are often passive and nonselective, necessitating functionalization for targeted delivery.

Conclusions:

• Cell-penetrating peptides (CPPs) are promising tools for targeted delivery of therapeutics and diagnostics.
• Effective clinical application requires careful design and functionalization of CPPs for specific cell or tissue targeting.
• Optimizing both the cargo and the CPP is crucial for successful systemic delivery systems.