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Antibody-mediated targeting of iron oxide nanoparticles to the folate receptor alpha increases tumor cell association in vitro and in vivo.

Ndong C, Toraya-Brown S, Kekalo K, Baker I, Gerngross TU, Fiering SN, Griswold KE - Int J Nanomedicine (2015)

Bottom Line: Here, we describe molecular targeting of iron oxide nanoparticles (IONPs) to the folate receptor alpha (FOLRα) using an engineered antibody fragment (Ffab).Interestingly, Ffab-IONPs built with custom 120 nm nanoparticles exhibited lower in vitro targeting efficiency when compared to those built with commercially sourced 180 nm nanoparticles.In vivo, however, the two Ffab-IONP platforms achieved equivalent tumor homing, although the smaller 120 nm IONPs were more prone to liver sequestration.

View Article: PubMed Central - PubMed

Affiliation: Thayer School of Engineering, Dartmouth, Hanover, NH, USA.

ABSTRACT
Active molecular targeting has become an important aspect of nanoparticle development for oncology indications. Here, we describe molecular targeting of iron oxide nanoparticles (IONPs) to the folate receptor alpha (FOLRα) using an engineered antibody fragment (Ffab). Compared to control nanoparticles targeting the non-relevant botulinum toxin, the Ffab-IONP constructs selectively accumulated on FOLRα-overexpressing cancer cells in vitro, where they exhibited the capacity to internalize into intracellular vesicles. Similarly, Ffab-IONPs homed to FOLRα-positive tumors upon intraperitoneal administration in an orthotopic murine xenograft model of ovarian cancer, whereas negative control particles showed no detectable tumor accumulation. Interestingly, Ffab-IONPs built with custom 120 nm nanoparticles exhibited lower in vitro targeting efficiency when compared to those built with commercially sourced 180 nm nanoparticles. In vivo, however, the two Ffab-IONP platforms achieved equivalent tumor homing, although the smaller 120 nm IONPs were more prone to liver sequestration. Overall, the results show that Ffab-mediated targeting of IONPs yields specific, high-level accumulation within cancer cells, and this fact suggests that Ffab-IONPs could have future utility in ovarian cancer diagnostics and therapy.

No MeSH data available.


Related in: MedlinePlus

TEM imaging of Ffab-IONP and Bfab-IONP subcellular localization following in vitro binding to FOLRα+ KB cancer cells.Notes: Magnification of 25,000× showing the binding of (A) Ffab-CMD and (D) Ffab-BNF on the KB cell surface (arrows). Magnification of 10,000× showing (B) Ffab-CMD and (E) Ffab-BNF within intracellular vesicles (arrows). Magnification of 25,000× showing no evidence of nanoparticles on KB tumor cells treated with (C) Bfab-CMD or (F) Bfab-BNF. Scale bars are 100 nm (A, C, D and F) and 500 nm (B and E).Abbreviations: TEM, transmission electron microscopy; fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; IONP, iron oxide nanoparticle; CMD, carboxymethyl-dextran; rFOLRα, recombinant folate receptor alpha; BNF, bionized nanoferrite; NP, nanoparticle.
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f5-ijn-10-2595: TEM imaging of Ffab-IONP and Bfab-IONP subcellular localization following in vitro binding to FOLRα+ KB cancer cells.Notes: Magnification of 25,000× showing the binding of (A) Ffab-CMD and (D) Ffab-BNF on the KB cell surface (arrows). Magnification of 10,000× showing (B) Ffab-CMD and (E) Ffab-BNF within intracellular vesicles (arrows). Magnification of 25,000× showing no evidence of nanoparticles on KB tumor cells treated with (C) Bfab-CMD or (F) Bfab-BNF. Scale bars are 100 nm (A, C, D and F) and 500 nm (B and E).Abbreviations: TEM, transmission electron microscopy; fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; IONP, iron oxide nanoparticle; CMD, carboxymethyl-dextran; rFOLRα, recombinant folate receptor alpha; BNF, bionized nanoferrite; NP, nanoparticle.

Mentions: As part of the KB cellular binding studies, the subcellular localization of Ffab-CMD and Ffab-BNF conjugates was analyzed by transmission electron microscopy (TEM). TEM micrographs showed that, following an 8-hour cellular incubation in vitro, Ffab-CMD and Ffab-BNF can be found accumulated on both the cell membrane as well as within intracellular vesicles (Figure 5A, B, D, E). Consistent with the negligible binding of Bfab-CMD and Bfab-BNF observed above (Figure 4C, D), no Bfab-targeted particles could be found in corresponding TEM images (Figure 5C, F). In aggregate, these results demonstrate specific and efficient targeting of FOLRα-positive cancer cells by Ffab-CMD and Ffab-BNF, and additionally, they reveal that the Ffab-targeting moiety facilitates cellular internalization of both nanoparticle constructs.


Antibody-mediated targeting of iron oxide nanoparticles to the folate receptor alpha increases tumor cell association in vitro and in vivo.

Ndong C, Toraya-Brown S, Kekalo K, Baker I, Gerngross TU, Fiering SN, Griswold KE - Int J Nanomedicine (2015)

TEM imaging of Ffab-IONP and Bfab-IONP subcellular localization following in vitro binding to FOLRα+ KB cancer cells.Notes: Magnification of 25,000× showing the binding of (A) Ffab-CMD and (D) Ffab-BNF on the KB cell surface (arrows). Magnification of 10,000× showing (B) Ffab-CMD and (E) Ffab-BNF within intracellular vesicles (arrows). Magnification of 25,000× showing no evidence of nanoparticles on KB tumor cells treated with (C) Bfab-CMD or (F) Bfab-BNF. Scale bars are 100 nm (A, C, D and F) and 500 nm (B and E).Abbreviations: TEM, transmission electron microscopy; fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; IONP, iron oxide nanoparticle; CMD, carboxymethyl-dextran; rFOLRα, recombinant folate receptor alpha; BNF, bionized nanoferrite; NP, nanoparticle.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4388088&req=5

f5-ijn-10-2595: TEM imaging of Ffab-IONP and Bfab-IONP subcellular localization following in vitro binding to FOLRα+ KB cancer cells.Notes: Magnification of 25,000× showing the binding of (A) Ffab-CMD and (D) Ffab-BNF on the KB cell surface (arrows). Magnification of 10,000× showing (B) Ffab-CMD and (E) Ffab-BNF within intracellular vesicles (arrows). Magnification of 25,000× showing no evidence of nanoparticles on KB tumor cells treated with (C) Bfab-CMD or (F) Bfab-BNF. Scale bars are 100 nm (A, C, D and F) and 500 nm (B and E).Abbreviations: TEM, transmission electron microscopy; fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; IONP, iron oxide nanoparticle; CMD, carboxymethyl-dextran; rFOLRα, recombinant folate receptor alpha; BNF, bionized nanoferrite; NP, nanoparticle.
Mentions: As part of the KB cellular binding studies, the subcellular localization of Ffab-CMD and Ffab-BNF conjugates was analyzed by transmission electron microscopy (TEM). TEM micrographs showed that, following an 8-hour cellular incubation in vitro, Ffab-CMD and Ffab-BNF can be found accumulated on both the cell membrane as well as within intracellular vesicles (Figure 5A, B, D, E). Consistent with the negligible binding of Bfab-CMD and Bfab-BNF observed above (Figure 4C, D), no Bfab-targeted particles could be found in corresponding TEM images (Figure 5C, F). In aggregate, these results demonstrate specific and efficient targeting of FOLRα-positive cancer cells by Ffab-CMD and Ffab-BNF, and additionally, they reveal that the Ffab-targeting moiety facilitates cellular internalization of both nanoparticle constructs.

Bottom Line: Here, we describe molecular targeting of iron oxide nanoparticles (IONPs) to the folate receptor alpha (FOLRα) using an engineered antibody fragment (Ffab).Interestingly, Ffab-IONPs built with custom 120 nm nanoparticles exhibited lower in vitro targeting efficiency when compared to those built with commercially sourced 180 nm nanoparticles.In vivo, however, the two Ffab-IONP platforms achieved equivalent tumor homing, although the smaller 120 nm IONPs were more prone to liver sequestration.

View Article: PubMed Central - PubMed

Affiliation: Thayer School of Engineering, Dartmouth, Hanover, NH, USA.

ABSTRACT
Active molecular targeting has become an important aspect of nanoparticle development for oncology indications. Here, we describe molecular targeting of iron oxide nanoparticles (IONPs) to the folate receptor alpha (FOLRα) using an engineered antibody fragment (Ffab). Compared to control nanoparticles targeting the non-relevant botulinum toxin, the Ffab-IONP constructs selectively accumulated on FOLRα-overexpressing cancer cells in vitro, where they exhibited the capacity to internalize into intracellular vesicles. Similarly, Ffab-IONPs homed to FOLRα-positive tumors upon intraperitoneal administration in an orthotopic murine xenograft model of ovarian cancer, whereas negative control particles showed no detectable tumor accumulation. Interestingly, Ffab-IONPs built with custom 120 nm nanoparticles exhibited lower in vitro targeting efficiency when compared to those built with commercially sourced 180 nm nanoparticles. In vivo, however, the two Ffab-IONP platforms achieved equivalent tumor homing, although the smaller 120 nm IONPs were more prone to liver sequestration. Overall, the results show that Ffab-mediated targeting of IONPs yields specific, high-level accumulation within cancer cells, and this fact suggests that Ffab-IONPs could have future utility in ovarian cancer diagnostics and therapy.

No MeSH data available.


Related in: MedlinePlus