HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Frank, J. A. Articles by Bulte, J. W. M. Search for Related Content PubMed PubMed Citation Articles by Frank, J. A. Articles by Bulte, J. W. M.

Clinically Applicable Labeling of Mammalian and Stem Cells by Combining Superparamagnetic Iron Oxides and Transfection Agents¹

¹ From the Experimental Neuroimaging Section, Laboratory of Diagnostic Radiology Research, Clinical Center, National Institutes of Health, Bldg 10, Rm B1N256, 10 Center Dr, MSC 1074, Bethesda, MD 20892-1074. Received May 30, 2002; revision requested July 29; final revision received October 9; accepted November 5. Address correspondence to J.A.F. (e-mail: jafrank@helix.nih.gov).

View larger version (105K): [in a new window]   Figure 1. Photomicrographs show Prussian blue staining of MSC, HeLa cells, mouse lymphocytes, and CG-4 cells incubated for various times with either ferumoxides alone or different dilutions (in parentheses) of TA and ferumoxides at 25 µg of iron per milliliter in culture media. A-D, MSCs incubated with ferumoxides for 2 hours (original magnification, x40): A, ferumoxides only; B, ferumoxides-PLL (PLL dilution, 1:1,250); C, ferumoxides-Superfect (1:1,250); and D, ferumoxides-PLUS/lipofectamine (1:1,250/1:2,500). E-H, HeLa cells incubated with ferumoxides for 24 hours (original magnification, x40): E, ferumoxides only; F, ferumoxides-PLL (1:2,000); G, ferumoxides-Superfect (1:2,000); and H, ferumoxides-PLUS/lipofectamine (1:2,000/1:4,000). I-K, Mouse lymphocytes incubated with ferumoxides for 24 hours (original magnification, x100): I, ferumoxides only; J, ferumoxides-PLL (1:2,000); and K, diaminobenzide-enhanced Prussian blue stain with ferumoxides-PLUS/lipofectamine (1:2,000/1:4,000). L, M, CG-4 cells incubated for 48 hours (original magnification, x100): L, ferumoxides only; and M, ferumoxides-PLL (1:125).

View larger version (104K): [in a new window]   Figure 2. A, Photomicrograph of HeLa cells incubated with MION-46L at 25 µg of iron per milliliter without a TA for 48 hours. There is no apparent uptake of MION-46L. B, Photomicrograph of HeLa cells magnetically labeled with MION-46L-PLL (dilution, 1:50). Intracytoplasmic SPIO particles are clearly visible with Prussian blue staining. (Original magnification, x40.)

View larger version (30K): [in a new window]   Figure 3. Bar graphs show 1/T2s (per second) for tau = 1 and 5 msec at 42 MHz at 23°C for MSC, HeLa cells, mouse lymphocytes (ML), and CG-4 cells that were incubated with various TAs and ferumoxides (for control cells, no iron added to the culture media). There is a clear interecho dependence observed for all cell types and ferumoxides-TA combinations, indicating a clustering of the SPIO nanoparticles within endosomes and cells. PL/LFA = PLUS/lipofectamine, SF = Superfect.

View larger version (37K): [in a new window]   Figure 4a. (a) Bar graph shows region of interest signal intensity measurement in arbitrary units (au) versus unlabeled (U) and ferumoxides-TA-labeled cell suspensions for the proton-density-weighted fast spin-echo MR images obtained at 1.5 T. (b) Similar bar graph of the same cell suspension with use of a gradient-echo MR sequence. For a and b, percentage change in signal intensity (ie, contrast derived from the Equation) between labeled and unlabeled control cell suspensions are given in parentheses at the end of each bar. Horizontal axis is divided into the following four cell lines: MSCs (white bars), HeLa cells (gray bars), mouse lymphocytes (ML) (black bars), and CG-4 cells (striped bars), as well as TAs (PL/LFA = PLUS/lipofectamine, SF = Superfect). Dilutions of TA for each cell line are provided in the text and the Figure 1 caption.

View larger version (34K): [in a new window]   Figure 4b. (a) Bar graph shows region of interest signal intensity measurement in arbitrary units (au) versus unlabeled (U) and ferumoxides-TA-labeled cell suspensions for the proton-density-weighted fast spin-echo MR images obtained at 1.5 T. (b) Similar bar graph of the same cell suspension with use of a gradient-echo MR sequence. For a and b, percentage change in signal intensity (ie, contrast derived from the Equation) between labeled and unlabeled control cell suspensions are given in parentheses at the end of each bar. Horizontal axis is divided into the following four cell lines: MSCs (white bars), HeLa cells (gray bars), mouse lymphocytes (ML) (black bars), and CG-4 cells (striped bars), as well as TAs (PL/LFA = PLUS/lipofectamine, SF = Superfect). Dilutions of TA for each cell line are provided in the text and the Figure 1 caption.

View larger version (21K): [in a new window]   Figure 5. Log-log plot of the signal intensities in arbitrary units (au) for fast spin-echo () and gradient-echo () MR images of the gel suspension of unlabeled control cells and ferumoxides-TA-labeled MSCs, HeLa cells, mouse lymphocytes, and CG-4 cells versus the 1/T2s for the suspension. The equations for the nonlinear regression analysis fit and regression r2 values are shown.