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Updated: Jul 2, 2026

Polymalic Acid-based Nano Biopolymers for Targeting of Multiple Tumor Markers: An Opportunity for Personalized Medicine?
Published on: June 13, 2014
Does a targeting ligand influence nanoparticle tumor localization or uptake?
Kathleen F Pirollo1, Esther H Chang
1Department of Oncology, Georgetown University Medical Center, Washington DC 20057-1469, USA.
Abstract:
Inclusion of a tumor-targeting molecule in nanosized delivery systems increases their in vivo efficacy. However, the biodistribution and pharmacokinetics of the uptake of such particles have not yet been well addressed. Several recent papers have suggested that tumor-targeting ligands function primarily to increase intracellular uptake of the nanocomplex and do not influence tumor localization. However, other reports indicate that they do play a role in the accumulation in the tumor. One difference might be the presence or absence of poly-[ethylene glycol] (PEG) in the complex and its impact on the enhanced permeability and retention (EPR) effect. Further studies are clearly needed to more fully elucidate the influence of composition on tumor-targeted, systemic delivery of nanoparticles.
Insights
Tumor-targeting molecules in nanodelivery systems enhance efficacy but their role in tumor localization versus cellular uptake requires further study. The presence of polyethylene glycol (PEG) and its effect on the enhanced permeability and retention (EPR) effect may be key factors.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Pharmacology
Background:
- Nanosized delivery systems with tumor-targeting molecules show increased in vivo efficacy.
- The precise role of these targeting molecules in biodistribution and pharmacokinetics remains unclear.
- Existing literature presents conflicting findings on whether ligands primarily enhance intracellular uptake or influence tumor localization.
Purpose of the Study:
- To investigate the influence of tumor-targeting molecules on nanoparticle biodistribution and pharmacokinetics.
- To clarify the role of targeting ligands in tumor localization versus intracellular uptake.
- To explore the impact of poly-[ethylene glycol] (PEG) and the enhanced permeability and retention (EPR) effect on targeted nanoparticle delivery.
Main Methods:
- Analysis of existing literature on nanoparticle targeting and delivery.
- Comparative assessment of studies with and without poly-[ethylene glycol] (PEG) modification.
- Evaluation of the enhanced permeability and retention (EPR) effect in nanoparticle accumulation.
Main Results:
- Tumor-targeting ligands may primarily enhance intracellular uptake rather than tumor localization.
- The presence or absence of poly-[ethylene glycol] (PEG) might differentiate nanoparticle behavior.
- The enhanced permeability and retention (EPR) effect is a critical factor influenced by nanoparticle composition.
Conclusions:
- Further research is essential to fully understand the complex interplay between nanoparticle composition, targeting ligands, and tumor delivery.
- Elucidating these factors will optimize the design of effective tumor-targeted nanodelivery systems.
- The influence of poly-[ethylene glycol] (PEG) on the EPR effect warrants detailed investigation for improved therapeutic outcomes.
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