Octreotide-Mediated Tumor-Targeted Drug Delivery via a Cleavable Doxorubicin-Peptide Conjugate

Area of Science:

• Bioconjugation Chemistry
• Cancer Therapeutics
• Drug Delivery Systems

Background:

• Targeted drug delivery aims to minimize side effects in cancer therapy.
• Challenges persist in creating stable yet releasable drug-carrier chemical bonds.
• Site-specific conjugation is crucial for effective drug delivery platforms.

Purpose of the Study:

• To develop a versatile platform for site-specific drug-carrier bioconjugate preparation.
• To create a doxorubicin-octreotide bioconjugate targeting somatostatin receptors on cancer cells.
• To enable triggered drug release within cancer cells.

Main Methods:

• Utilized a novel cleavable disulfide-intercalating linker for bioconjugation.
• Prepared a doxorubicin-octreotide conjugate targeting somatostatin receptors.
• Assessed tumor targeting and hormone secretion suppression using radioimmunoassay.
• Evaluated drug release kinetics in the presence of glutathione.
• Performed cytotoxicity assays on pituitary, pancreatic, and breast cancer cell lines.

Main Results:

• The doxorubicin-octreotide bioconjugate effectively targeted cancer cells.
• The tumor homing peptide retained receptor interaction after drug attachment.
• Drug release was efficiently triggered by the physiological reducing agent glutathione.
• Cytotoxicity was demonstrated against various cancer cell lines.

Conclusions:

• The novel platform enables site-specific preparation of versatile drug-carrier conjugates.
• The doxorubicin-octreotide bioconjugate shows potential for targeted cancer therapy.
• Triggered intracellular drug release is feasible with this system.