Aromatic Dipeptide Homologue-Based Hydrogels for Photocontrolled Drug Release

Abstract

Peptide-based hydrogels are considered of special importance due to their biocompatibility and biodegradability. They have a wide range of applications in the biomedical field, such as drug delivery, tissue engineering, wound healing, cell culture media, and biosensing. Nevertheless, peptide-based hydrogels composed of natural α-amino acids are limited for in vivo applications because of the possible degradation by proteolytic enzymes. To circumvent this issue, the incorporation of extra methylene groups within the peptide sequence and the protection of the terminal amino group can increase the enzymatic stability. In this context, we investigated the self-assembly capacity of aromatic dipeptides (Boc-α-diphenylalanine and Boc-α-dityrosine) and their β- and γ-homologues and developed stable hydrogels. Surprisingly, only the Boc-diphenylalanine analogues were able to self-assemble and form hydrogels. A model drug, l-ascorbic acid, and oxidized carbon nanotubes (CNTs) or graphene oxide were then incorporated into the hydrogels. Under near-infrared light irradiation, the photothermal effect of the carbon nanomaterials induced the destabilization of the gel structure, which caused the release of a high amount of drug, thus providing opportunities for photocontrolled on-demand drug release.

Novel Trends in Hydrogel Development for Biomedical Applications: A Review

“…Therefore, CBNs, such as graphene oxide (GO), CNTs and graphene quantum dots (GQDs) have been extensively studied in biomedical applications [ 251 , 252 ]. Guilbaud et al (2022) studied hydrogels based on short homopeptides (Boc-α-diphenylalanine and Boc-α-dityrosine) containing light-responsive nanomaterials (CNTs and GO), which offered interesting results for the development of promising systems for controlled on-demand drug release applications [ 253 ]. Park et al (2022) investigated the design and manufacture of three types of hybrid poly(NIPAAm-co-BBVIm) (pNIBBIm) and CTS hydrogels with incorporated CNTs for smart drug delivery systems, with remarkable thermal and electrical responsive properties that enabled the development of an excellent controllable and switchable drug delivery platform for biomedical approaches [ 254 ].…”

Plasmonic lipogels: driving co-assembly of composites with peptide-based gels for controlled drug release

“…Yet, few works report the use of peptide-based hydrogels together with liposomes as a means to compartmentalize drugs and achieve better control over the drug delivery system, 1,3 as well as the use of NIR to stimulate drug release. 55,56 In a previous work, our group demonstrated that photothermia could be used to enhance curcumin drug release from peptide-based hydrogels, 43 but this simple drug-hydrogel combination is limited to stable or well encapsulated drugs, or thermally-responsive hydrogels. If a hydrophilic molecule is loaded in a gel, its release is strongly driven by passive release and the control over it becomes limited to few choices, such as changing the hydrogel network density, as reported in the present work, in which photothermia did not enhance CF release in hydrogels.…”

“…Yet, few works report the use of peptide-based hydrogels together with liposomes as a means to compartmentalize drugs and achieve better control over the drug delivery system, 1,3 as well as the use of NIR to stimulate drug release. 55,56…”

Peptide-Based Supramolecular Hydrogels as Drug Delivery Agents: Recent Advances

“…This process was applied to the on-demand release of ascorbic acid. Interestingly, the same structures containing tyrosine instead of phenylalanine failed to produce hydrogels, indicating a detrimental influence of the phenol OH group on the self-assembly process [ 59 ].…”