Cell penetrating peptides: a comparative transport analysis for 474 sequence motifs

Area of Science:

• Molecular Medicine
• Biotechnology
• Cell Biology

Background:

• Cell-penetrating peptides (CPPs) are crucial for intracellular reagent delivery in molecular medicine.
• Existing research lacks standardized comparisons of CPP performance for cargo transport.
• Developing efficient CPPs is vital for advancing therapeutic applications.

Purpose of the Study:

• To systematically evaluate and compare the cell-penetrating efficiency of a large set of CPPs.
• To identify key sequence-based features correlating with enhanced cargo delivery.
• To provide a curated list of high-performing CPPs for future research.

Main Methods:

• Collected sequence data for 474 CPPs from scientific literature.
• Synthesized CPPs and conjugated them with carboxyfluorescein (FAM) as a model cargo.
• Quantified cellular uptake via fluorescence intensity measurements in HeLa cells under standardized conditions.

Main Results:

• Observed a 70-fold variation in transport efficiency among the tested CPPs compared to cargo alone.
• Identified strong positive correlations between CPP uptake efficiency and both sequence length and net positive charge.
• Documented significant differences in cargo delivery capabilities across the CPP candidates.

Conclusions:

• Standardized evaluation revealed substantial variability in CPP-mediated cellular uptake.
• CPP sequence length and positive charge are critical determinants of efficient cargo delivery.
• A list of top-performing CPPs is provided, facilitating selection for optimized intracellular delivery applications.