Cell-Penetrating Peptides Using Cyclic α,α-Disubstituted α-Amino Acids with Basic Functional Groups.

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Delivery Systems

Background:

• Cell-penetrating peptides (CPPs) are crucial for delivering cell-impermeable molecules intracellularly.
• Developing efficient and safe delivery tools remains a significant challenge in molecular biology.

Purpose of the Study:

• To design and synthesize novel CPPs by incorporating cyclic α,α-disubstituted α-amino acids (dAAs).
• To evaluate the cell-penetrating abilities and plasmid DNA (pDNA) delivery efficiency of these modified CPPs.

Main Methods:

• Synthesis of four types of cyclic dAAs with basic functional groups and varying chirality.
• Incorporation of these dAAs into arginine (Arg)-rich peptides.
• Assessment of cell permeability and pDNA delivery efficacy compared to a standard Arg nonapeptide and a commercial reagent.

Main Results:

• Peptides containing the novel cyclic dAAs demonstrated superior cell permeability compared to the Arg nonapeptide.
• These modified CPPs facilitated better pDNA delivery than a commercial transfection reagent, especially with extended incubation times.

Conclusions:

• The incorporation of cyclic dAAs with basic functional groups into Arg-rich peptides is a promising strategy for developing effective CPPs.
• These novel CPPs show potential as efficient tools for plasmid DNA delivery applications.