Materials that exhibit responsiveness toward biological signals are currently subjected to intense research in the field of drug delivery. In our study, we tried to develop cancer-targeted and redox-responsive nanoparticles (NPs) from disulfide-linked oxidized cysteine-phenylalanine (CFO). The NPs were conjugated with folic acid (FA) to specifically target cancer cells, and the presence of disulfide bonds would enabled the disintegration of the particles in the presence of elevated levels of glutathione (GSH) in cancer cells. Anticancer drug doxorubicin (Dox) was successfully loaded inside the disulfide-linked nanoparticles (CFO-Dox-NPs), which further demonstrated stimuli-responsive drug release in the presence of GSH. We have also demonstrated enhanced uptake of FA-derivatized NPs (FA-CFO-NPs) in cancerous cells (C6 glioma and B16F10 melanoma cells) than in normal cells (HEK293T cells) due to the overexpression of FA receptors on the surface of cancer cells. Cytotoxicity studies in C6 cells and B16F10 cells further revealed enhanced efficacy of Dox loaded (FA-CFO-Dox-NPs) as compared to the native drug. The findings of this study clearly demonstrated that the disulfide-linked nanoparticle system may provide a promising selective drug delivery platform in cancer cells.

Curcumin (Ccm) has shown immense potential as an antimalarial agent; however its low solubility and less bioavailability attenuate the in vivo efficacy of this potent compound. In order to increase Ccm’s bioavailability, a number of organic/inorganic polymer based nanoparticles have been investigated. However, most of the present day nano based delivery systems pose a conundrum with respect to their complex synthesis procedures, poor in vivo stability and toxicity issues. Peptides due to their high biocompatibility could act as excellent materials for the synthesis of nanoparticulate drug delivery systems. Here, we have investigated dehydrophenylalanine (ΔPhe) di-peptide based self-assembled nanoparticles for the efficient delivery of Ccm as an antimalarial agent. The self-assembly and curcumin loading capacity of different ΔPhe dipeptides, phenylalanine–α,β-dehydrophenylalanine (FΔF), arginine-α,β-dehydrophenylalanine (RΔF), valine-α,β-dehydrophenylalanine (VΔF) and methonine-α,β-dehydrophenylalanine (MΔF) were investigated for achieving enhanced and effective delivery of the compound for potential anti-malarial therapy. FΔF, RΔF, VΔF and MΔF peptides formed different types of nanoparticles like nanotubes and nanovesicles under similar assembling conditions. Out of these, F∆F nanotubes showed maximum curcumin loading capacity of almost 68 % W/W. Ccm loaded F∆F nanotubes (Ccm-F∆F) showed comparatively higher (IC50, 3.0 µM) inhibition of Plasmodium falciparum (Indo strain) as compared to free Ccm (IC50, 13 µM). Ccm-F∆F nano formulation further demonstrated higher inhibition of parasite growth in malaria infected mice as compared to free Ccm. The dipeptide nanoparticles were highly biocompatible and didn’t show any toxic effect on mammalian cell lines and normal blood cells. This work provides a proof of principle of using highly biocompatible short peptide based nanoparticles for entrapment and in vivo delivery of Ccm leading to an enhancement in its efficacy as an antimalarial agent.

The deadly pandemic, coronavirus disease 2019 (COVID‐19), caused due to the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has paralyzed the world. Although significant methodological advances have been made in the field of viral detection/diagnosis with 251 in vitro diagnostic tests receiving emergency use approval by the US‐FDA, little progress has been made in identifying curative or preventive therapies. This review discusses the current trends and potential future approaches for developing COVID‐19 therapeutics, including repurposed drugs, vaccine candidates, immune‐modulators, convalescent plasma therapy, and antiviral nanoparticles/nanovaccines/combinatorial nanotherapeutics to surmount the pandemic viral strain. Many potent therapeutic candidates emerging via drug‐repurposing could significantly reduce the cost and duration of anti‐COVID‐19 drug development. Gene/protein‐based vaccine candidates that could elicit both humoral and cell‐based immunity would be on the frontlines to prevent the disease. Many emerging nanotechnology‐based interventions will be critical in the fight against the deadly virus by facilitating early detection and enabling target oriented multidrug therapeutics. The therapeutic candidates discussed in this article include remdesivir, dexamethasone, hydroxychloroquine, favilavir, lopinavir/ritonavir, antibody therapeutics like gimsilumab and TJM2, anti‐viral nanoparticles, and nanoparticle‐based DNA and mRNA vaccines.

Molecular self-assembly is a widespread natural phenomenon and has inspired several researchers to synthesize a compendium of nano/microstructures with widespread applications. Biomolecules like pr...