Tumor Microenvironment pH-Sensitive Peptidomimetics for Targeted Anticancer Drug Delivery

Area of Science:

• Biochemistry
• Drug Delivery
• Nanotechnology

Background:

• Cell-penetrating peptides (CPPs) facilitate intracellular delivery of therapeutics but often cause nonselective uptake and toxicity due to high cationic charges.
• Developing CPPs with improved selectivity and reduced toxicity is crucial for effective drug delivery.

Purpose of the Study:

• To design and evaluate a novel pH-sensitive cell-penetrating peptidomimetic (Hkd) for selective anticancer drug delivery to tumor cells.
• To investigate the mechanism of Hkd-mediated cellular uptake and its response to acidic tumor microenvironments.
• To assess the efficacy and safety of Hkd conjugated with camptothecin (Cpt) for cancer therapy.

Main Methods:

• Design of a decamer peptidomimetic (Hkd) incorporating a pH-sensitive histidine residue and a rigid cyclic dipeptide core.
• Pharmacokinetic studies to evaluate serum stability.
• Cellular uptake studies at varying pH conditions.
• Conjugation of Hkd to camptothecin (Cpt) and evaluation of targeted delivery and therapeutic potential in cancer cells.

Main Results:

• Hkd demonstrated excellent serum stability.
• Cellular uptake of Hkd was significantly enhanced at lower pH, characteristic of tumor microenvironments.
• Hkd-conjugated camptothecin (Cpt) exhibited reduced nonselective transport to normal cells and effective delivery to cancer cells.
• The conjugated drug retained its therapeutic potential, showing efficacy against cancer cells.

Conclusions:

• The designed Hkd peptidomimetic offers a pH-sensitive and selective approach for intracellular drug delivery.
• Hkd overcomes limitations of traditional cationic CPPs, improving stability and targeting.
• This strategy holds promise for advancing targeted cancer therapy and expanding CPP applications.