A Comparative Study on Albumin-Binding Molecules for Targeted Tumor Delivery through Covalent and Noncovalent Approach

Bioconjug Chem. 2019 Dec 18;30(12):3107-3118. doi: 10.1021/acs.bioconjchem.9b00760. Epub 2019 Dec 3.

Abstract

Various types of albumin-binding molecules have been conjugated to anticancer drugs, and these modified prodrugs could be effective in cancer treatments compared to free anticancer drugs. However, the tumor targeting of albumin-binding prodrugs has not been clearly investigated. Herein, we examined the in vitro and in vivo tumor-targeting efficiency of three different albumin-binding molecules including albumin-binding peptide (DICLPRWGCLW: PEP), fatty acid (palmitic acid: PA), and maleimide (MI), respectively. In order to characterize the different targeting efficiency of albumin-binding molecules, PEP, PA, or MI was chemically labeled with near-infrared fluorescence (NIRF) dye, Cy5.5, in resulting PEP-Cy5.5, PA-Cy5.5, and MI-Cy5.5. These NIRF dye-labeled albumin-binding molecules were physically or chemically bound to albumin via gentle incubation in aqueous conditions in vitro. Notably, PA-Cy5.5 with reversible and multivalent binding affinities formed stable albumin complexes, compared to PEP-Cy5.5 and MI-Cy5.5, confirmed via surface plasmon resonance measurement, gel electrophoresis assay, and albumin-bound column-binding test. In tumor-bearing mice model, the different albumin-binding affinities of PA-Cy5.5, PEP-Cy5.5, and MI-Cy5.5 greatly contributed to their tumor-targeting ability. Even though the binding affinity of PEP-Cy5.5 and MI-Cy5.5 to albumin is higher than that of PA-Cy5.5 in vitro, intravenous PA-Cy5.5 showed a higher tumor-targeting efficiency in tumor-bearing mice compared to that of PEP-Cy5.5 and MI-Cy5.5. The reversible and multivalent affinities of albumin-binding molecules to native serum albumin greatly increased the pharmacokinetics and tumor-targeting efficiency in vivo.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antineoplastic Agents / administration & dosage
  • Antineoplastic Agents / chemistry*
  • Carbocyanines / analysis
  • Carbocyanines / chemistry
  • Drug Delivery Systems / methods*
  • Humans
  • Maleimides / chemistry
  • Maleimides / therapeutic use
  • Mice
  • Palmitic Acid / chemistry
  • Palmitic Acid / therapeutic use
  • Peptides / chemistry
  • Peptides / therapeutic use
  • Prodrugs / chemistry*
  • Protein Binding
  • Serum Albumin / metabolism*

Substances

  • Antineoplastic Agents
  • CY5.5 cyanine dye
  • Carbocyanines
  • Maleimides
  • Peptides
  • Prodrugs
  • Serum Albumin
  • maleimide
  • Palmitic Acid