Novel cationic lipophilic peptides for oligodeoxynucleotide delivery

Area of Science:

• Biotechnology
• Molecular Biology
• Drug Delivery Systems

Background:

• Oligodeoxynucleotides (ODNs) require efficient delivery systems for therapeutic applications.
• Novel peptide-based agents are being explored to improve cellular uptake and delivery efficacy.
• Core peptide (CP) derived from the T-cell receptor (TCR) alpha-chain shows cell entry and IL-2 inhibition properties.

Purpose of the Study:

• To evaluate novel peptides, CP and its lipophilic analogue LP, as agents for ODN delivery.
• To assess the impact of increased lipophilicity on peptide cellular uptake, toxicity, and biological activity.
• To compare the transfection efficiency of CP and LP with a commercial agent.

Main Methods:

• Synthesis of a lipoamino acid-conjugated peptide (LP) from core peptide (CP).
• Assessment of hemolytic activity to determine toxicity.
• Evaluation of IL-2 production inhibition in T-cells and Caco-2 cell permeability assays.
• Isothermal titration calorimetry (ITC) to determine peptide-ODN complex ratios.
• Transfection of ODN1-peptide complexes into retinal pigment epithelial cells and measurement of hVEGF production.

Main Results:

• Neither CP nor LP exhibited hemolytic activity, indicating low toxicity.
• LP showed enhanced cellular uptake and greater inhibition of IL-2 production compared to CP.
• CP and LP demonstrated effective ODN1 delivery, achieving 47% and 55% more inhibition of hVEGF production, respectively.
• Both peptides exhibited higher transfection efficiency than the commercial agent cytofectin GSV.

Conclusions:

• The core peptide (CP) and its lipophilic derivative (LP) are non-toxic and effective agents for oligodeoxynucleotide (ODN) delivery.
• LP's enhanced lipophilicity significantly improves cellular permeability and ODN delivery efficiency.
• These peptides represent promising candidates for developing advanced ODN delivery systems in gene therapy and related fields.