Development of cationic peptide-based hydrogels loaded with iopamidol for CEST-MRI detection

Abstract

Peptide-based hydrogels have been recently investigated as materials for biomedical applications like tissue engineering and delivery of drugs and imaging agents. Among the synthetic peptide hydrogelators, the cationic hexapeptides Ac-K1...

Advances in Hydrogel-Based Drug Delivery Systems

“…Gregorio et al developed soft, injectable, and biocompatible hydrogels, Ac-K1 and Ac-K2, incorporated with iopamidol-an iodinated contrast agent authorized for X-ray computed tomography. These hydrogels exhibit efficiency for CEST-MRI, highlighting their potential as smart MRI-detectable hydrogels [148]. Furthermore, Li et al designed a pH-responsive injectable hydrogel composed of the octapeptide FOE, which disintegrates within the tumor microenvironment.…”

Hybrid PNA-peptide hydrogels as injectable CEST-MRI agents

“…According to this latter strategy, we recently proposed peptide-based hydrogels (HGs) as supramolecular contrast agents (CAs) in magnetic resonance imaging (MRI) applications. 17,18 These HGs were generated by the self-assembly of cationic hexapeptides (K1 = ILVAGK, K2 = LIVAGK or K3 = AIVAGK) derivatized at their N-terminus with the fluorenyl-(Fmoc-) or the acetyl (Ac-) group. By starting from these macroscopic HGs, we also prepared their submicronized version, named nanogels (NGs) that can be used as injectable nanocarriers, alternative to liposomes and polymeric micelles, for increasing the CA concentration in the target site.…”

“…By starting from these macroscopic HGs, we also prepared their submicronized version, named nanogels (NGs) that can be used as injectable nanocarriers, alternative to liposomes and polymeric micelles, for increasing the CA concentration in the target site. 17,18 Hydrogels of Ac-K and Fmoc-K peptides were demonstrated to be able to encapsulate two different types of MRI contrast agents: (i) gadolinium complexes ([Gd(BOPTA)] 2À ), [Gd(DTPA)] 2À , and ([Gd(AAZTA)] À ) belonging to the class of T 1 -MRI CAs 17 and (ii) iopamidol, a clinically approved CT agent also acting as a chemical exchange saturation transfer (CEST)-MRI probe. [18][19][20] CEST-MRI represents a versatile technique for generating MRI contrast, alternative to the classical T 1 and/or T 2 relaxation mechanism.…”

“…17,18 Hydrogels of Ac-K and Fmoc-K peptides were demonstrated to be able to encapsulate two different types of MRI contrast agents: (i) gadolinium complexes ([Gd(BOPTA)] 2À ), [Gd(DTPA)] 2À , and ([Gd(AAZTA)] À ) belonging to the class of T 1 -MRI CAs 17 and (ii) iopamidol, a clinically approved CT agent also acting as a chemical exchange saturation transfer (CEST)-MRI probe. [18][19][20] CEST-MRI represents a versatile technique for generating MRI contrast, alternative to the classical T 1 and/or T 2 relaxation mechanism. In particular, it is very efficient for the monitoring of tissue pH and the detection of endogenous mobile proteins.…”

Ultrashort Cationic Peptide Fmoc-FFK as Hydrogel Building Block for Potential Biomedical Applications

“…Among all peptide-based architectures (e.g., fibers [3], nanospheres [4], and micelles [5]), hydrogels (HGs) represent highly organized materials in which the network, generated by interconnected fibers, is able to retain, due to the hydrophilic portions of the amide skeleton, large amounts of water [6,7]. Thanks to their capabilities to accommodate active pharmaceutical ingredients (APIs) in their pores and to mimic the extracellular matrix because of their swollen structure, HGs have been successfully tested as drugs or contrast agents' reservoirs and as matrices for tissue engineering applications [8,9]. The chemical, physical and mechanical properties of the hydrogel can be easily modulated by the opportune design of the peptide sequence, since the choice of the length, the amino acid lateral side and the insertion of aromatic or aliphatic groups at the N-terminus have a significant impact on its gelation capability and HG features [10][11][12][13].…”