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Dual-modal magnetic resonance/fluorescent imaging (MRI/FI) attracts moreandmoreattentions in diagnosis of tumors. A corresponding dual-modal imaging agent with sufficient tumor sensitivity and specificity should be matched to improve imaging quality. Tripeptide (RGD) and pentapeptide (YIGSR) were selected as the tumor-targeting groups and attached to gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and rhodamine B (RhB), and then make two novel polypeptide-based derivatives (RGD-Gd-DTPA-RhB and YIGSR-Gd-DTPA-RhB), respectively. These derivatives were further characterized and their properties, such as cell uptake, cell cytotoxicity, MRI and FI assay, were measured. YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB had high relaxivity, good tumor-targeting property, low cell cytotoxicity and good red FI in B16F10 melanoma cells. Moreover, YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB possessed high uptake to B16F10 melanoma, and then achieve highly enhanced FI and MRI of tumors in mice for a prolonged time. Therefore, YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB can be applied as the potential agents for tumor targeted MRI/FI in vivo., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Inc.)

Objective: Gadolinium diethylenetriaminepentaacetic di[5-(4'-amidophenyl)-10,15,20- tris(4'-sulfonatophenyl) porphyrin trisodium salt] (Gd-DTPA-2APTSPP) was synthesized by the reaction of diethylenetriaminepentaacetic dianhydride with 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin and subsequently chelation with gadolium chloride., Methods: This gadolinium complex was characterized and its properties in vitro and in vivo were also evaluated. Compared with Gd-DTPA, Gd-DTPA-2APTSPP possessed high relaxivity r1, low cytotoxicity to HeLa cells and high enhanced signal intensities of the VX2 carcinoma in rabbits for a prolonged time., Conclusion: Moreover, Gd-DTPA-2APTSPP can distinguish the VX2 carcinoma from the reactive hyperplasia incited by inflammation and normal tissues in rabbits. Therefore, Gd-DTPA-2APTSPP can be taken up selectively by tumors and show the potential as a tumor-targeting MRI contrast agent., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors., (Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.)

Purpose: The aim was to investigate three dextran gadolinium complexes Dextran-DTPA-Gd as the potential MRI contrast agents in lymphatic system., Methods: Three dextran gadolinium complexes Dextran-DTPA-Gd containing differing amounts of Gd-DTPA were synthesized by the incorporation of Gd-DTPA to the hydroxyl groups of dextran. These dextran ligands and gadolinium complexes were characterized, and their properties in vitro and in vivo were also evaluated., Results: Dextran-DTPA-Gd demonstrated obviously higher relaxation effectiveness than that of Gd-DTPA. The result of in vitro cytotoxicity assay showed that these macromolecular ligands and their corresponding gadolinium complexes had low cytotoxicity to HeLa cells. Dextran-DTPA-Gd greatly enhanced the contrast of MR images of normal politeal lymph nodes and reactive hyperplasia of politeal lymph nodes in rabbits and provided prolonged duration in lymphatic system with lower injection doses than that of Gd-DTPA. However, Dextran-DTPA-Gd displayed low signal enhancements in MR images of politeal lymph nodes with VX2 carcinoma in rabbits during the detection time., Conclusions: These dextran gadolinium complexes Dextran-DTPA-Gd can be taken up selectively by lymphatic system and showed the potential as MRI contrast agents in lymphatic system.

Both diethylenetriaminepentaacetic acid (DTPA) and sulfadiazine (SD) were incorporated into polyaspartamides with different side chains, including poly-alpha,beta-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA), poly-alpha,beta-[N- (3-hydroxypropyl)-L-aspartamide] (PHPA), poly-alpha,beta-[N-(2-aminoethy1)-L-aspartamide] (PAEA), poly-alpha,beta-[N-(4-aminobuty1)-L-aspartamide] (PABA), and poly-alpha,beta-[N-(6-aminohexyl)-L-aspartamide] (PAHA). The polyaspartamide ligands containing DTPA and SD groups were further reacted with gadolinium chloride to give the corresponding macromolecular gadolinium complexes. Experimental data of 1H NMR, IR, UV, and elemental analysis exhibited the formation of the polyaspartamide ligands and gadolinium complexes. Relaxivity studies indicated that the macromolecular chelates possess higher relaxivities than that of the clinically used Gd-DTPA. MR imaging showed that the macromolecular chelate PAEA-Gd-DTPA-SD greatly enhanced the contrast of MR images of hepatoma in the lower limb of mice and provided prolonged intravascular duration. Thus the polyaspartamide gadolinium complex containing SD groups is expected to be used as the potential macromolecular MRI contrast agents for hepatoma in mice.

Diethylenetriaminepentaacetic acid (DTPA) and pyridoxamine (PM) were incorporated into the amine groups on the surface of ammonia-core poly(amidoamine) dendrimers (PAMAM, Generation 2.0-5.0) to obtain dendritic ligands. These dendritic ligands were reacted with gadolinium chloride to yield the corresponding dendritic gadolinium (Gd) complexes. The dendritic ligands and their gadolinium complexes were characterized by(1)HNMR, IR, UV and elemental analysis. Relaxivity studies showed that the dendritic gadolinium complexes possessed higher relaxation effectiveness compared with the clinically used Gd-DTPA. After administration of the dendritic gadolinium complexes (0.09 mmol kg(-1) ) to rats, magnetic resonance imaging of the liver indicated that the dendritic gadolinium complexes containing pyridoxamine groups enhanced the contrast of the MR images of the liver, provided prolonged intravascular duration and produced highly contrasted visualization of blood vessels.

Folate-containing dextran ligand (FA-Dextran-DTPA) was synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and folate (FA) as a tumor-targeting group into dextran as a polymer carrier. This ligand was further reacted with gadolinium chloride to make a dextran gadolinium complex FA-Dextran-DTPA-Gd. The ligand and its gadolinium complex were characterized by H-NMR, FTIR, UV-Vis, average particle sizes and zeta potential, as well. In vitro properties including relaxivity, cytotoxicity assay, cellular uptake assay, and magnetic resonance imaging (MRI) were also evaluated. Compared with Gd-DTPA, FA-Dextran-DTPA-Gd possessed obviously higher relaxation effectiveness and lower cytotoxicity to HeLa cells. FA-Dextran-DTPA-Gd had a high affinity to the H460 and MDA-MB-231 tumor cells and can be taken up selectively by these tumor cells. Moreover, FA-Dextran-DTPA-Gd showed enhanced signal intensities (SI) of MRI and enhanced the contrast of MR images of tumor cells. These results indicated that FA-Dextran-DTPA-Gd showed the potential as a tumor-targeting contrast agent in MRI. [ABSTRACT FROM AUTHOR]