Blind⿿ targeting in action: From phage display to breast cancer cell targeting with peptide-gold nanoconjugates

Anti-amyloidogenic hexapeptide-coated gold nanoparticles for enhanced inhibition of amyloid formation: A promising therapeutic approach

Under specific external stimulus, misfolded and natively disordered globular proteins undergo irreversible transformation into pathogenic β-sheet-rich insoluble fibrillar structure, and deposition of theses fibrils in cells and tissues leads to disorders like Alzheimer's, Dementia, Type II diabetes, and many more. Here, we have developed a positively-charged Arg-containing hexapeptide, SqP7, and elucidated its anti-amyloidogenic propensity on in vitro HEWL amyloid formation under acidic and neutral fibrillation conditions using computational tools and several biophysical techniques. SqP7, at a five-fold molar excess, displayed excellent amyloid inhibition capability at both pH conditions (~83 % and 72 % inhibition under acidic and neutral fibrillation conditions, respectively), and was further chosen as a coating agent on gold nanoparticles. This was done to investigate whether coating of this peptide on gold nanoparticles has any effect on its anti-amyloidogenic efficiency and effective inhibition concentration. The synthesized SqP7-coated gold nanoparticles were characterized to be spherical and highly-dispersed having a mean diameter of 9.12 ± 2.08 nm. The anti-amyloidogenic capability of the synthesized SqP7-coated gold nanoparticles was further evaluated, and a 10-fold reduction in the effective inhibition concentration of SqP7 was observed. This peptide‑gold nanoparticle based integrated approach can lead to the development of highly effective therapeutics for amyloid-related diseases, offering improved prevention and treatment options.

Biomedical applications of the peptide decorated gold nanoparticles

Currently, peptide-nanoparticle (NP) conjugates have been demonstrated to be efficient and powerful tools for the treatment and the diagnosis of various diseases as well as in the bioimaging application. Several bioconjugation strategies have been adopted to formulate the peptide-NP conjugates. In this review, we discuss the exciting applications of peptide-gold (Au) NP conjugates in the area of drug delivery, targeting, cancer therapy, brain diseases, vaccines, immune modulation, biosensor, colorimetric detection of heavy metals, and bio-labeling in vitro and in vivo models. Within this framework, various approaches such as radiotherapy, photothermal therapy, photodynamic therapy and chemo-photothermal therapy have been demonstrated for the treatment of several diseases. Moreover, we highlight how the morphology, size, density of peptide and the protein corona influence the biological activity, biodistribution and biological fate of peptide-AuNP conjugates. In the end, we discuss the future outlook and the challenges being faced in the clinical translation of the peptide-AuNP conjugates. Overall, this review emphasizes that the peptide-AuNP conjugates might be used as potential theranostic agents for the treatment of life-threatening diseases in an economical fashion in the future.

Designing Chimeric Molecules for Drug Discovery by Leveraging Chemical Biology

After the first seed concept introduced in the 18th century, different disciplines have attributed different names to dual-functional molecules depending on their application, including bioconjugates, bifunctional compounds, multitargeting molecules, chimeras, hybrids, engineered compounds. However, these engineered constructs share a general structure: a first component that targets a specific cell and a second component that exerts the pharmacological activity. A stable or cleavable linker connects the two modules of a chimera. Herein, we discuss the recent advances in the rapidly expanding field of chimeric molecules leveraging chemical biology concepts. This Perspective is focused on bifunctional compounds in which one component is a lead compound or a drug. In detail, we discuss chemical features of chimeric molecules and their use for targeted delivery and for target engagement studies.

One Step Preparation of Peptide-Coated Gold Nanoparticles with Tunable Size

Gold nanoparticles (AuNPs) made from self-assembling peptides have been used in many research fields and attracted a great deal of attention due to their high stability, biocompatibility and functionality. However, existing preparation methods for peptide-coated AuNPs are post-synthesis processes, which are complicated and time consuming. Therefore, a one-step preparation method for peptide-coated AuNPs is proposed here. The AuNPs obtained by this method exhibit good stability. Importantly, peptide-coated AuNPs with precise different sizes can be prepared by this method through pH control of reducing reagent tyrosine in range of 10.0~12.7. Thus, the one-step preparation method proposed here provides a significant tool for the research in different fields concerning NP size, stability and biocompatibility.