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Published on: December 15, 2010
Effect of folate-targeted nanoparticle size on their rates of penetration into solid tumors
Erina Vlashi1, Lindsay E Kelderhouse, Jennifer E Sturgis
1Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States.
Abstract:
Targeted therapies are emerging as a preferred strategy for the treatment of cancer and other diseases. To evaluate the impact of a high affinity targeting ligand on the rate and extent of tumor penetration of different sized nanomedicines, we have used intravital multiphoton microscopy to quantitate the kinetics of tumor accumulation of a homologous series of folate-PEG-rhodamine conjugates prepared with polyethylene glycols (PEG) of different molecular weights. We demonstrate that increasing the size of the folate-PEG-rhodamine conjugates results in both longer circulation times and slower tumor penetration rates. Although a "binding site barrier" is observed with the folate-linked polymers in folate receptor expressing tumors, ligand targeting eventually leads to increased tumor accumulation, with endocytosis of the targeted nanocarriers contributing to their enhanced tumor retention. Because the effects of nanocarrier size, shape, chemistry, and targeting ligand are interconnected and complex, we suggest that these parameters must be carefully optimized for each nanocarrier to ensure optimal drug delivery in vivo.
Insights
Optimizing nanomedicine delivery involves balancing size and targeting. Larger nanocarriers circulate longer but penetrate tumors slower, requiring careful design for effective cancer therapy.
Area of Science:
- Nanomedicine
- Cancer Therapy
- Drug Delivery
Background:
- Targeted therapies are crucial for treating cancer and other diseases.
- Nanomedicine offers a promising platform for targeted drug delivery.
- Understanding nanocarrier behavior in vivo is essential for therapeutic success.
Purpose of the Study:
- To evaluate how nanomedicine size impacts tumor penetration and accumulation.
- To investigate the role of high-affinity targeting ligands in nanomedicine delivery.
- To analyze the kinetics of tumor accumulation for different-sized nanomedicines.
Main Methods:
- Intravital multiphoton microscopy was used to quantify tumor accumulation kinetics.
- A homologous series of folate-PEG-rhodamine conjugates with varying polyethylene glycol (PEG) molecular weights were synthesized.
- The study analyzed the impact of nanocarrier size on circulation time and tumor penetration rates.
Main Results:
- Increasing nanocarrier size led to longer circulation times and slower tumor penetration.
- A "binding site barrier" was observed in folate receptor-expressing tumors.
- Ligand targeting ultimately increased tumor accumulation, with endocytosis enhancing retention.
Conclusions:
- Nanomedicine size significantly influences circulation time and tumor penetration dynamics.
- Ligand targeting can overcome penetration barriers and enhance tumor accumulation.
- Careful optimization of nanocarrier parameters (size, shape, chemistry, ligand) is critical for effective in vivo drug delivery.
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