Drug-Mimicking Nanofibrous Peptide Hydrogel for Inhibition of Inducible Nitric Oxide Synthase

Abstract

In this work, we develop a drug-mimicking nanofibrous peptide hydrogel that shows long-term bioactivity comparable to a small-molecule inhibitor of inducible nitric oxide synthase (iNOS). The iNOS inhibitor, N 6-(1-iminoethyl)-l-lysine (l-NIL), is a positively charged amino acid whose structure could be readily integrated into the framework of a positively charged multidomain peptide (MDP) through the modification of lysine side chains. This new l-NIL-MDP maintains the self-assembling properties of the base peptide, forming β-sheet nanofibers, which entangle into a thixotropic hydrogel. The l-NIL-MDP hydrogel supports cell growth in vitro and allows syringe-directed delivery that persists in a targeted location in vivo for several weeks. Multiple characterization assays demonstrate the bioactivity of the l-NIL-MDP hydrogel to be comparable to the l-NIL small molecule. This includes iNOS inhibition of macrophages in vitro, reduced nitrotyrosine immunostaining in murine subcutaneous histology, and reduced serum levels of vascular endothelial growth factor in vivo. This study expands the toolbox of available peptide hydrogel scaffold designs that can modify biological activity without the need for any additional small-molecule drugs, proteins, or cells.

Influence of injection technique, drug formulation and tumor microenvironment on intratumoral immunotherapy delivery and efficacy

“…Variations in hydrogel composition, however, can potentially overcome this limitation to combine the benefits of hydrogel-based intratumoral deposition with the pharmacokinetic advantages of sustained drug release. 16 17 …”

Recent Progress in the Design and Application of Supramolecular Peptide Hydrogels in Cancer Therapy

“…For instance, Hartgerink and coworkers integrated a hydrophilic drug N6-(1-iminoethyl)-L-lysine ( L -NIL) (an inhibitor of inducible nitric oxide synthase, iNOS) into K 2 (SL) 6 K 2 MDP to give L -NIL-MDP, which showed comparable activity in inhibiting inducible nitric oxide synthase (iNOS) in vitro and in vivo. [150] Yang et al used tuftsin (TKPR) with Nap-G D F D F D Y to form a hybrid peptide compound Nap-G D F D F D YTKPR, which formed hydrogel and enhanced the maturation of DCs and phagocytosis of macrophages. [151] Similarly, Ruokolainen et al conjugated carnosine dipeptide (alanine-histidine, AH) onto a KTT sequence from "Matrixyl" lipopeptides to a lipopeptide C16KTT AH, which showed dosedependent cytotoxicity to MCF-7 cancer cells.…”

Current Progress in Cross-Linked Peptide Self-Assemblies

“…Peptide fibers composed of natural amino acids with high biocompatibility have recently been developed in view of practical applications. Typical examples are peptide fibers developed by Hartgerink that contain repeated hydrophilic serine (S) and hydrophobic isoleucine (L) peptide sequences forming β -sheets as a self-assembly unit ( Figure 2 b) [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]. Functional peptides can be incorporated to the termini of the peptide fibers forming “double domain-type peptide fibers” where the self-assembly unit and the functional part can be designed individually.…”

“…It was also confirmed that peptide fibers were formed, even when leucine is replaced to phenylalanine, tyrosine, or tryptophan [ 42 ]. Since the self-assembly unit is composed of neutral amino acid residues, charged amino acids can be incorporated to the self-assembly part [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ]. Peptide fibers containing repeated cationic arginine, hydrophobic alanine, anionic aspartic acid, and hydrophobic alanine residues (RADA sequence) have been reported by Zhang [ 55 ].…”

“…In pioneer works, amphiphilic peptides having hydrophobic alkyl chain at the termini of hydrophilic peptides have been designed, and their fundamental properties and applications to biomaterials have been investigated [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Currently, both amphiphilic peptides and other peptide-based self-assembly units have been found, enabling the design of peptide fibers with a variety of functions [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , …”