Dynamic Contrast-Enhanced Folate-Receptor-Targeted MR Imaging Using a Gd-loaded PEG-Dendrimer–Folate Conjugate in a Mouse Xenograft Tumor Model

Abstract

We have demonstrated the targeting ability of PEG-G3-(Gd-DTPA)11-(folate)5 in vitro and in vivo. A 17% cut-off point for a 30-min washout percentage can be a useful parameter for the diagnosis of FR-positive tumors.

Controlled intracellular self-assembly of gadolinium nanoparticles as smart molecular MR contrast agents

“…Common strategy for increasing the longitudinal molar relaxivity ( r 1 ) of T 1 CA is to prolong its rotational correlation time ( τ r i.e., the tumbling time of the CA in the water bulk). To achieve this goal, Gd-based agents with higher molecular weights such as Gd functionalized polymer, peptide amphiphiles or viral caspid, dendrimer, liposomes, nanoparticles, micelles, zeolites, fullerenes, carbon nanotubes, clays, and quantum dots were prepared and explored89101112. Nevertheless, these pre-made gadolinium complexes are facing the problem of cell membrane translocation and targeting, besides the difficulty and reproducibility of their fabrications13.…”

MRI with Gadolinium‐Based Nanoparticles

“…dendrimers have also been conjugated to several small targeting molecules such as folate that is directed against folate receptor expressing ovarian cancers [109][110][111], CLT1 peptide targeting the fibrin-fibronectin complexes in tumor [112], or an RGd-cyclopeptide targeting integrin α V β 3 [113]. Also, peGylation of the surface of a dendrimer combined with the conjugation to peptide T7 targeting transferin highly expressed in brain and liver tumor led to enhancement of the imaging of tumors in the liver, but not in the brain [114].…”

Nanoparticle-Based Delivery System for Application of siRNA In Vivo

“…Therefore, the ligands specific for these receptors can be used to modify siRNA molecules to increase the targeting ability of the delivery system, such as enhancing the efficacy, reducing the dosage, minimizing toxicity to normal cells and weakening the immune response. Commonly used ligands include the v 3 integrin ligand, RGD [115], transferrin [77], and the folate receptor [116][117][118]. With RGD-modification, PAMAM dendrimer-coated siRNA molecules inhibited the adhesion and aggregation ability of tumor cells, thereby preventing tumor development [115].…”

“…Many anti-cancer drugs, such as prodrug-enzymes, toxic proteins, liposome drugs, and nucleic acid molecules such as siRNA, can be combined with folic acid to achieve the target. For example, liposomes [116] or dendrimer polymer [117]-wrapped siRNA nanoparticles can be modified with folic acid to inhibit growth of a targeted tumor. The imaging substances, such as radiological contrast media or MRI contrast agents, can play an important role in tumor diagnosis because of their specific accumulation in situ when combined with folate receptor.…”