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Reformulating Tylocrebrine in Epidermal Growth Factor Receptor Targeted Polymeric Nanoparticles Improves Its Therapeutic Index.

Kirtane AR, Wong HL, Guru BR, Lis LG, Georg GI, Gurvich VJ, Panyam J - Mol. Pharm. (2015)

Bottom Line: Through in vitro studies in different cancer cell lines, we found that EGFR targeted nanoparticles were significantly more effective in killing tumor cells than the free drug.In vivo pharmacokinetic studies revealed that encapsulation in nanoparticles resulted in lower brain penetration and enhanced tumor accumulation of the drug.These results suggest that the therapeutic index of drugs that were previously considered unusable could be significantly improved by reformulation.

View Article: PubMed Central - PubMed

Affiliation: †Department of Pharmaceutics, ‡Institute of Therapeutics Discovery and Development, §Department of Medicinal Chemistry, and ⊥Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.

ABSTRACT
Several promising anticancer drug candidates have been sidelined owing to their poor physicochemical properties or unfavorable pharmacokinetics, resulting in high overall cost of drug discovery and development. Use of alternative formulation strategies that alleviate these issues can help advance new molecules to the clinic at a significantly lower cost. Tylocrebrine is a natural product with potent anticancer activity. Its clinical trial was discontinued following the discovery of severe central nervous system toxicities. To improve the safety and potency of tylocrebrine, we formulated the drug in polymeric nanoparticles targeted to the epidermal growth factor receptor (EGFR) overexpressed on several types of tumors. Through in vitro studies in different cancer cell lines, we found that EGFR targeted nanoparticles were significantly more effective in killing tumor cells than the free drug. In vivo pharmacokinetic studies revealed that encapsulation in nanoparticles resulted in lower brain penetration and enhanced tumor accumulation of the drug. Further, targeted nanoparticles were characterized by significantly enhanced tumor growth inhibitory activity in a mouse xenograft model of epidermoid cancer. These results suggest that the therapeutic index of drugs that were previously considered unusable could be significantly improved by reformulation. Application of novel formulation strategies to previously abandoned drugs provides an opportunity to advance new molecules to the clinic at a lower cost. This can significantly increase the repertoire of treatment options available to cancer patients.

No MeSH data available.


Related in: MedlinePlus

Cell uptakeof EGFR-targeted and nontargeted nanoparticles. (A)A549 cells were incubated with coumarin 6 loaded targeted nanoparticleswith or without excess peptide, or nontargeted nanoparticles for 1h at 4 °C. Treatments were removed, and the cells were incubatedin fresh media at 37 °C for 1 h. Intracellular levels of coumarin6 were estimated using HPLC. (B) A431 cells were incubated with tylocrebrine-loadednanoparticles. After 1 h, treatments were removed, and the cells werewashed. Intracellular tylocrebrine concentration was measured usingHPLC and normalized to cell protein. Data represented as mean ±SD, n = 6, ∗ indicates p <0.05.
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fig5: Cell uptakeof EGFR-targeted and nontargeted nanoparticles. (A)A549 cells were incubated with coumarin 6 loaded targeted nanoparticleswith or without excess peptide, or nontargeted nanoparticles for 1h at 4 °C. Treatments were removed, and the cells were incubatedin fresh media at 37 °C for 1 h. Intracellular levels of coumarin6 were estimated using HPLC. (B) A431 cells were incubated with tylocrebrine-loadednanoparticles. After 1 h, treatments were removed, and the cells werewashed. Intracellular tylocrebrine concentration was measured usingHPLC and normalized to cell protein. Data represented as mean ±SD, n = 6, ∗ indicates p <0.05.

Mentions: By using fluorescent dye labeled particles, we first determinedifcellular uptake of targeted nanoparticles was greater than that ofnontargeted nanoparticles. We found that targeted nanoparticles resultedin ∼2–3-fold higher uptake than nontargeted nanoparticles.Additionally, uptake of targeted nanoparticles was reduced (not statisticallysignificant) in the presence of excess free targeting peptide (Figure 5A). This indicated that the enhanced uptake of targetednanoparticles could be mediated via EGFR. Additional experiments investigatinguptake in EGFR knockout cells are needed to confirm this finding.


Reformulating Tylocrebrine in Epidermal Growth Factor Receptor Targeted Polymeric Nanoparticles Improves Its Therapeutic Index.

Kirtane AR, Wong HL, Guru BR, Lis LG, Georg GI, Gurvich VJ, Panyam J - Mol. Pharm. (2015)

Cell uptakeof EGFR-targeted and nontargeted nanoparticles. (A)A549 cells were incubated with coumarin 6 loaded targeted nanoparticleswith or without excess peptide, or nontargeted nanoparticles for 1h at 4 °C. Treatments were removed, and the cells were incubatedin fresh media at 37 °C for 1 h. Intracellular levels of coumarin6 were estimated using HPLC. (B) A431 cells were incubated with tylocrebrine-loadednanoparticles. After 1 h, treatments were removed, and the cells werewashed. Intracellular tylocrebrine concentration was measured usingHPLC and normalized to cell protein. Data represented as mean ±SD, n = 6, ∗ indicates p <0.05.
© Copyright Policy - editor-choice
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525301&req=5

fig5: Cell uptakeof EGFR-targeted and nontargeted nanoparticles. (A)A549 cells were incubated with coumarin 6 loaded targeted nanoparticleswith or without excess peptide, or nontargeted nanoparticles for 1h at 4 °C. Treatments were removed, and the cells were incubatedin fresh media at 37 °C for 1 h. Intracellular levels of coumarin6 were estimated using HPLC. (B) A431 cells were incubated with tylocrebrine-loadednanoparticles. After 1 h, treatments were removed, and the cells werewashed. Intracellular tylocrebrine concentration was measured usingHPLC and normalized to cell protein. Data represented as mean ±SD, n = 6, ∗ indicates p <0.05.
Mentions: By using fluorescent dye labeled particles, we first determinedifcellular uptake of targeted nanoparticles was greater than that ofnontargeted nanoparticles. We found that targeted nanoparticles resultedin ∼2–3-fold higher uptake than nontargeted nanoparticles.Additionally, uptake of targeted nanoparticles was reduced (not statisticallysignificant) in the presence of excess free targeting peptide (Figure 5A). This indicated that the enhanced uptake of targetednanoparticles could be mediated via EGFR. Additional experiments investigatinguptake in EGFR knockout cells are needed to confirm this finding.

Bottom Line: Through in vitro studies in different cancer cell lines, we found that EGFR targeted nanoparticles were significantly more effective in killing tumor cells than the free drug.In vivo pharmacokinetic studies revealed that encapsulation in nanoparticles resulted in lower brain penetration and enhanced tumor accumulation of the drug.These results suggest that the therapeutic index of drugs that were previously considered unusable could be significantly improved by reformulation.

View Article: PubMed Central - PubMed

Affiliation: †Department of Pharmaceutics, ‡Institute of Therapeutics Discovery and Development, §Department of Medicinal Chemistry, and ⊥Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, United States.

ABSTRACT
Several promising anticancer drug candidates have been sidelined owing to their poor physicochemical properties or unfavorable pharmacokinetics, resulting in high overall cost of drug discovery and development. Use of alternative formulation strategies that alleviate these issues can help advance new molecules to the clinic at a significantly lower cost. Tylocrebrine is a natural product with potent anticancer activity. Its clinical trial was discontinued following the discovery of severe central nervous system toxicities. To improve the safety and potency of tylocrebrine, we formulated the drug in polymeric nanoparticles targeted to the epidermal growth factor receptor (EGFR) overexpressed on several types of tumors. Through in vitro studies in different cancer cell lines, we found that EGFR targeted nanoparticles were significantly more effective in killing tumor cells than the free drug. In vivo pharmacokinetic studies revealed that encapsulation in nanoparticles resulted in lower brain penetration and enhanced tumor accumulation of the drug. Further, targeted nanoparticles were characterized by significantly enhanced tumor growth inhibitory activity in a mouse xenograft model of epidermoid cancer. These results suggest that the therapeutic index of drugs that were previously considered unusable could be significantly improved by reformulation. Application of novel formulation strategies to previously abandoned drugs provides an opportunity to advance new molecules to the clinic at a lower cost. This can significantly increase the repertoire of treatment options available to cancer patients.

No MeSH data available.


Related in: MedlinePlus