Intracellular Self‐Assembly of Peptide Conjugates for Tumor Imaging and Therapy

Abstract

Intracellular self‐assembly (ISA) is a versatile and powerful strategy for in situ constructing sophisticated and functional supramolecular nanostructures, which has been widely applied in biomedicine and biomedical engineering. Among the common building blocks for ISA, peptides have attracted increasingly attention due to their intrinsic bioactivity, biocompatibility, and biodegradability. Particularly, by conjugating functional motifs (e.g., probes or drugs) to peptides to yield the peptide conjugates, the latter show enhanced stability and efficiency, and probably new functions. In recent years, employing ISA of peptide conjugates for tumor imaging and treatment has achieved great progresses. Therefore, the recent progress of ISA of peptide conjugates is summarized in this progress report. Moreover, several examples of ISA of peptide conjugates for other important imaging or therapeutic applications are also introduced. Finally, a brief perspective on remaining challenges and potential directions for future research in this area is presented.

Supramolecular Nanomedicines of In-Situ Self-Assembling Peptides

“…Therefore, in recent years, researchers have begun to construct materials from in-situ SA short peptides that respond to special stimuli in living cells and animals, and achieve biological functions by fine-tuning the structure of short peptides and assembly strategies. (Deng et al, 2021). The pathological environment is usually different from normal tissue, which may be manifested in the following aspects: pH (Boedtkjer and Pedersen, 2020), enzymes (Shahriari et al, 2019), reactive oxygen species (ROS) (Aggarwal et al, 2019) and glutathione .…”

Mitochondria-Targeted Self-Assembly of Peptide-Based Nanomaterials

“…In the previous section, we discussed the assembled peptidenanomaterials that locate mitochondria. Recently, the in situ selfassembly attracts much attention due to its spatiotemporal precision and activable bioeffects, emerging as a frontier in the biomedical field (Deng et al, 2021;Kwek et al, 2021;Liu et al, 2021a;Wang et al, 2021b). The specific enzymes and overexpressed ROS can be used to trigger the self-assembly around or on the surface of mitochondria in situ.…”

Advances and Perspectives of Peptide and Polypeptide‐Based Materials for Biomedical Imaging

“…Intracellular self-assembly strategy enables to construct supramolecular nanostructures through in situ self-assembly at specific intracellular sites. [58] Compared to traditional "always on" contrast agents, whose imaging signals could be detected through the whole imaging process, intracellular self-assembly platforms could keep the signal "off" until they reach the targeted physiological tissues or organs. [29,58,59] This activatable characteristic of this intracellular self-assembly platform significantly enhances the signal-to-noise ratio for more accurate and efficient imaging.…”

“…[58] Compared to traditional "always on" contrast agents, whose imaging signals could be detected through the whole imaging process, intracellular self-assembly platforms could keep the signal "off" until they reach the targeted physiological tissues or organs. [29,58,59] This activatable characteristic of this intracellular self-assembly platform significantly enhances the signal-to-noise ratio for more accurate and efficient imaging. In particular, responsive peptides are suitable to construct intracellular self-assembly imaging platforms.…”