Skip to Content
Merck
  • Development and characterization of an antibody-labeled super-paramagnetic iron oxide contrast agent targeting prostate cancer cells for magnetic resonance imaging.

Development and characterization of an antibody-labeled super-paramagnetic iron oxide contrast agent targeting prostate cancer cells for magnetic resonance imaging.

PloS one (2014-05-14)
David Bates, Suraj Abraham, Michael Campbell, Ingeborg Zehbe, Laura Curiel
ABSTRACT

In this study we developed, characterized and validated in vitro a functional superparagmagnetic iron-oxide based magnetic resonance contrast agent by conjugating a commercially available iron oxide nanoparticle, Molday ION Rhodamine-B Carboxyl (MIRB), with a deimmunized mouse monoclonal antibody (muJ591) targeting prostate-specific membrane antigen (PSMA). This functional contrast agent is intended for the specific and non-invasive detection of prostate cancer cells that are PSMA positive, a marker implicated in prostate tumor progression and metastasis. The two-step carbodiimide reaction used to conjugate the antibody to the nanoparticle was efficient and we obtained an elemental iron content of 1958 ± 611 per antibody. Immunofluorescence microscopy and flow cytometry showed that the conjugated muJ591:MIRB complex specifically binds to PSMA-positive (LNCaP) cells. The muJ591:MIRB complex reduced cell adhesion and cell proliferation on LNCaP cells and caused apoptosis as tested by Annexin V assay, suggesting anti-tumorigenic characteristics. Measurements of the T2 relaxation time of the muJ591:MIRB complex using a 400 MHz Innova NMR and a multi-echo spin-echo sequence on a 3T MRI (Achieva, Philips) showed a significant T2 relaxation time reduction for the muJ591:MIRB complex, with a reduced T2 relaxation time as a function of the iron concentration. PSMA-positive cells treated with muJ591:MIRB showed a significantly shorter T2 relaxation time as obtained using a 3T MRI scanner. The reduction in T2 relaxation time for muJ591:MIRB, combined with its specificity against PSMA+LNCaP cells, suggest its potential as a biologically-specific MR contrast agent.

MATERIALS
Product Number
Brand
Product Description

USP
Sodium bicarbonate, United States Pharmacopeia (USP) Reference Standard
Supelco
Chloroform, analytical standard
Sigma-Aldrich
Chloroform, anhydrous, contains amylenes as stabilizer, ≥99%
Sigma-Aldrich
Chloroform, anhydrous, ≥99%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Sodium bicarbonate, tested according to Ph. Eur.
Sigma-Aldrich
Chloroform, ≥99%, PCR Reagent, contains amylenes as stabilizer
Sigma-Aldrich
Sodium bicarbonate, BioXtra, 99.5-100.5%
Sigma-Aldrich
Sodium bicarbonate, powder, BioReagent, for molecular biology, suitable for cell culture, suitable for insect cell culture
Sigma-Aldrich
Wilmad® NMR tubes 5 mm diam., precision, frequency 500 MHz, L 7 in.
Supelco
Chloroform, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Chloroform, suitable for HPLC, ≥99.8%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Sodium bicarbonate, ACS reagent, ≥99.7%
Sigma-Aldrich
Chloroform, ACS spectrophotometric grade, ≥99.8%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Chloroform, contains ethanol as stabilizer, meets analytical specification of BP, 99-99.4% (GC)
Sigma-Aldrich
Chloroform, contains ethanol as stabilizer, ACS reagent, ≥99.8%
Supelco
Residual Solvent - Acetonitrile, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Sodium bicarbonate, puriss., meets analytical specification of Ph. Eur., BP, USP, FCC, E500, 99.0-100.5%, powder
Sigma-Aldrich
Sodium bicarbonate, anhydrous, free-flowing, Redi-Dri, ReagentPlus®, ≥99.5%
Sigma-Aldrich
Chloroform, ReagentPlus®, ≥99.8%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Chloroform, biotech. grade, ≥99.8%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Chloroform, contains 100-200 ppm amylenes as stabilizer, ≥99.5%
Sigma-Aldrich
Sodium bicarbonate, ReagentPlus®, ≥99.5%, powder
Sigma-Aldrich
Sodium bicarbonate, anhydrous, free-flowing, Redi-Dri, ACS reagent, ≥99.7%
Sigma-Aldrich
Chloroform, contains amylenes as stabilizer, ACS reagent, ≥99.8%
Sigma-Aldrich
Sodium hydrogencarbonate, −40-+140 mesh, ≥95%
Sigma-Aldrich
Chloroform, puriss. p.a., reag. ISO, reag. Ph. Eur., 99.0-99.4% (GC)
Sigma-Aldrich
Chloroform, HPLC Plus, for HPLC, GC, and residue analysis, ≥99.9%, contains amylenes as stabilizer
Sigma-Aldrich
Chloroform, suitable for HPLC, ≥99.8%, amylene stabilized
Sigma-Aldrich
Chloroform, HPLC Plus, for HPLC, GC, and residue analysis, ≥99.9%, contains 0.5-1.0% ethanol as stabilizer
Sigma-Aldrich
Deuterium oxide, 70 atom % D