Cell-penetrating peptide, or CPP for short, is a short peptide that can penetrate through the cell membranes and directly enter the cytosol to facilitate intracellular. CPPs can deliver the cargo into the cells, which can be a very promising tool for drug delivery system to deliver the candidate drugs as the sequence and function diversity of the peptides. There are many internalization pathways for CPPs, such as direct penetration through the cellular membrane, endocytosis-mediated cell entry followed by endosomolysis, and receptor-mediated uptake.
Figure 1. peptide 3D illustration
Examples: Tat, Arginine oligomer
Examples: MPG-8, BPrPp, Pep-1, Penetratin, CADY
Examples: mAb-R9, A1-Tat, RVG-R9
Examples: ACPP
CPPs can deliver siRNA into the cells by conjugation with siRNA. Up to now, more than 100 CPPs have been identified, and they are different in 3D conformations, polarity, hydrophilicity, hydrophobicity, electric charges, and length of amino acids. T hey display different functions including siRNA binding, membrane penetration, endosome disruption, and targeting.
The 5'-internal or 3'-terminus of a siRNA can be linked to N-internal or C-terminus of a peptide using preactivated small molecules with functional groups residing in peptides to form peptide-siRNA conjugates.
We provide peptide-siRNA conjugates with high quality. We can design and synthesis the siRNA based on the target gene, and our parent company BOC Sciences can provide high quality peptides, we can conjugate them to form peptide-siRNA conjugates.
CPPs enable efficient cellular uptake through multiple internalization pathways, enhance endosomal escape, and provide versatile conjugation options while maintaining siRNA functionality across diverse cell types.
CPPs are classified into hydrophilic, amphiphilic, targeting ligand-conjugated, and activatable categories, with selection based on target cell permeability, endosomal escape efficiency, and cargo compatibility requirements.
Strategic attachment at the 5'-internal or 3'-terminus of siRNA using optimized linker chemistry preserves RNA-induced silencing complex formation and gene targeting capability.
Amphiphilic CPPs combine hydrophobic and hydrophilic domains that facilitate membrane interaction, promote endosomal disruption, and improve cytoplasmic release of conjugated siRNA molecules.
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