Peptide-based materials that have diverse structures and functionalities are an important type of biomaterials. In former times, peptide-based nanomaterials with excellent stability were constructed through self-assembly. Compared with individual peptides, peptide-based self-assembly nanomaterials that form well-ordered superstructures possess many advantages such as good thermo- and mechanical stability, semiconductivity, piezoelectricity and optical properties. Moreover, due to their excellent biocompatibility and biological activity, peptide-based self-assembly nanomaterials have been vastly used in different fields. In this review, we provide the advances of peptide-based self-assembly nanostructures, focusing on the driving forces that dominate peptide self-assembly and assembly mechanisms of peptides. After that, we outline the synthesis and properties of peptide-based nanomaterials, followed by the applications of functional peptide nanomaterials. Finally, we provide perspectives on the challenges and future of peptide-based nanomaterials.

As a novel semiconducting materials, BP-QDs possess superior transfection efficiency, excellent biocompatibility and low cytotoxicity, which shows promising potential for siRNA delivery and photothermal effects in cancer therapy.

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

An easily accessible fluorescent dye, FEB, which has a high fluorescence quantum yield and is suitable for in vivo tumour imaging is reported.

Vascular endothelial growth factor receptors (VEGFRs) are well recognized as significant biomarkers of tumor angiogenesis. Herein, we have developed a first-of-its-kind peptide-based VEGFR positron emission tomography (PET) tracer. The novel [ 64 Cu]VEGF 125−136 peptide possessed satisfactory radio-characteristics and showed good specificity for the visualization of VEGFR in various mouse models, in which the tumorspecific radioactivity uptake was highly correlated to the VEGFR expression level. Moreover, the tracer showed high tumor uptake (ca. 5.89 %ID/g at 20 min postinjection in B16F10 mice) and excellent pharmacokinetics, achieving the maximum imaging quality within 1 h after injection. These features convey [ 64 Cu]VEGF 125−136 as a promising, clinically translatable PET tracer for the imaging of tumor angiogenesis.

Direct inhibition of the protein-protein interaction of ERα and its endogenous coactivators with a cell permeable stabilized peptide may offer a novel, promising strategy for combating ERα positive breast cancers. Here, we report the co-crystal structure of a helical peptide stabilized by a N-terminal unnatural cross-linked aspartic acid (TD) in complex with the ERα ligand binding domain (LBD). We designed a series of peptides and peptide 6 that showed direct and high-affinity binding to ERα with selective antiproliferative activity in ERα positive breast cancer cells. The co-crystal structure of the TD-stabilized peptide 6 in complex with ERα LBD further demonstrates that it forms an α helical conformation and directly binds at the coactivator binding site of ERα. Further studies showed that peptide 6 could potently inhibit cellular ERα's transcriptional activity. This approach demonstrates the potential of TD stabilized peptides to modulate various intracellular protein-protein interactions involved in a range of disorders.

Based on their ability to self-assemble and mimic strategies that occur in nature, peptide nanomaterials offer a variety of potential applications in environmentally friendly energy storage technologies.

Native peptide-based PET tracers were developed for PD-L1 imaging. The pegylation of the peptide improves the pharmacokinetics and biodistribution of the tracers.