Proton relaxation enhancement by means of serum albumin and poly-L-lysine labeled with DTPA-Gd3+ : relaxivities as a function of molecular weight and conjugation efficiency

• Published in: Magnetic resonance imaging Vol. 10; no. 6; pp. 913 - 917
• Main Authors: SPANOGHE, M, LANENS, D, DOMMISSE, R, VAN DER LINDEN, A, ALDERWEIRELDT, F
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Science 1992
• Subjects: Biological and medical sciences; Gadolinium DTPA; Investigative techniques, diagnostic techniques (general aspects); Isotope Labeling - methods; Magnetic Resonance Spectroscopy; Medical sciences; Miscellaneous. Technology; Molecular Weight; Organometallic Compounds; Pentetic Acid; Polylysine; Protons; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Serum Albumin, Bovine; Relaxation; Radiolabelling; Paramagnetic contrast agent; Proton; Exploration; Gadolinium; Lysine polymer; Serum albumin; Radiopharmaceuticals; Nuclear magnetic resonance imaging; Molecular weight
• ISSN: 0730-725X; 1873-5894
• DOI: 10.1016/0730-725X(92)90445-6

A series of poly-L-lysine chains, with molecular weight ranging from 3300 up to 102,000 Da, were labeled with DTPA-Gd3+. No significant differences in longitudinal and transversal relaxivity, could be demonstrated as a function of the chain length. The R1 and R2 relaxivities were respectively 2.5 and 5 times superior to those of plain DTPA-Gd3+ (at 2.4 T). Bovine serum albumin was also labeled in a way that a wide (DTPA-Gd3+)/BSA range (3-39) was obtained. The longitudinal relaxivity, of these paramagnetically labeled albumins, increased with increasing (DTPA-Gd3+)/BSA ratios. This effect was most pronounced at very low (DTPA-Gd3+)/BSA ratios.