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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

Binding analysis of Ffab and Bfab antibody fragments.Notes: (A) Representative ELISA binding profile of Ffab (closed square) and Bfab (open circle) with rFOLRα protein. (B) Representative cell-based ELISA for Ffab (closed symbols) and Bfab (open symbols) binding to FOLR+/HER2+ KB cells (squares) or FOLR−/HER2+ SKBR3 cells (triangles). Error bars represent standard deviation from technical triplicates.Abbreviations: fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; ELISA, enzyme-linked immunosorbent assay; FOLR, folate receptor; rFOLRα, recombinant folate receptor alpha; HER2, human epidermal growth factor receptor 2.
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f3-ijn-10-2595: Binding analysis of Ffab and Bfab antibody fragments.Notes: (A) Representative ELISA binding profile of Ffab (closed square) and Bfab (open circle) with rFOLRα protein. (B) Representative cell-based ELISA for Ffab (closed symbols) and Bfab (open symbols) binding to FOLR+/HER2+ KB cells (squares) or FOLR−/HER2+ SKBR3 cells (triangles). Error bars represent standard deviation from technical triplicates.Abbreviations: fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; ELISA, enzyme-linked immunosorbent assay; FOLR, folate receptor; rFOLRα, recombinant folate receptor alpha; HER2, human epidermal growth factor receptor 2.

Mentions: Binding of Ffab and Bfab to recombinant FOLRα (rFOLRα) was initially analyzed by ELISA. The biotin-labeled Ffab fragment exhibited a half maximal effective concentration (EC50) of 12 nM, whereas no binding was observed with the biotinylated Bfab control (Figure 3A). Additionally, more detailed rFOLRα binding kinetics were analyzed by biolayer interferometry (Figure S2). Ffab-maleimide-PEG2-biotin was immobilized on streptavidin biosensor tips and assayed with rFOLRα protein. The equilibrium dissociation constant for Ffab (KD =14 nM) was comparable to the EC50 obtained by ELISA (Figure 3A). Importantly, no detectable binding of Bfab-maleiemide-PEG2-biotin was observed with rFOLRα using the same streptavidin biosensors tips (data not shown). In aggregate, the quantitative binding studies with rFOLRα demonstrated that the engineered Ffab retained good binding affinity to rFOLRα, to which the parental Farletuzumab IgG was found to have a KD =2 nM.20


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)

Binding analysis of Ffab and Bfab antibody fragments.Notes: (A) Representative ELISA binding profile of Ffab (closed square) and Bfab (open circle) with rFOLRα protein. (B) Representative cell-based ELISA for Ffab (closed symbols) and Bfab (open symbols) binding to FOLR+/HER2+ KB cells (squares) or FOLR−/HER2+ SKBR3 cells (triangles). Error bars represent standard deviation from technical triplicates.Abbreviations: fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; ELISA, enzyme-linked immunosorbent assay; FOLR, folate receptor; rFOLRα, recombinant folate receptor alpha; HER2, human epidermal growth factor receptor 2.
© Copyright Policy
Related In: Results  -  Collection

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

f3-ijn-10-2595: Binding analysis of Ffab and Bfab antibody fragments.Notes: (A) Representative ELISA binding profile of Ffab (closed square) and Bfab (open circle) with rFOLRα protein. (B) Representative cell-based ELISA for Ffab (closed symbols) and Bfab (open symbols) binding to FOLR+/HER2+ KB cells (squares) or FOLR−/HER2+ SKBR3 cells (triangles). Error bars represent standard deviation from technical triplicates.Abbreviations: fab, an engineered monoclonal antibody fragment; Ffab, Farletuzufab, engineered from monoclonal antibody Farletuzumab; Bfab, Botulifab anti-botulinum toxin fab fragment; ELISA, enzyme-linked immunosorbent assay; FOLR, folate receptor; rFOLRα, recombinant folate receptor alpha; HER2, human epidermal growth factor receptor 2.
Mentions: Binding of Ffab and Bfab to recombinant FOLRα (rFOLRα) was initially analyzed by ELISA. The biotin-labeled Ffab fragment exhibited a half maximal effective concentration (EC50) of 12 nM, whereas no binding was observed with the biotinylated Bfab control (Figure 3A). Additionally, more detailed rFOLRα binding kinetics were analyzed by biolayer interferometry (Figure S2). Ffab-maleimide-PEG2-biotin was immobilized on streptavidin biosensor tips and assayed with rFOLRα protein. The equilibrium dissociation constant for Ffab (KD =14 nM) was comparable to the EC50 obtained by ELISA (Figure 3A). Importantly, no detectable binding of Bfab-maleiemide-PEG2-biotin was observed with rFOLRα using the same streptavidin biosensors tips (data not shown). In aggregate, the quantitative binding studies with rFOLRα demonstrated that the engineered Ffab retained good binding affinity to rFOLRα, to which the parental Farletuzumab IgG was found to have a KD =2 nM.20

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