Elongated self-assembled nanocarriers: From molecular organization to therapeutic applications

Conformation Influences Biological Fates of Peptide-Based Nanofilaments by Modulating Protein Adsorption and Interfilament Entanglement

Filamentous structures exert biological functions mediated by multivalent interactions with their counterparts in sharp contrast with spherical ones. The physicochemical properties and unique behaviors of nanofilaments that are associated with multivalent interaction with protein are poorly understood. Here, peptide-based nanofilaments containing different homotetrapeptidic inserts are reported and their protein adsorption and biological fates are tested. By altering the homotetrapeptides, different peptidic conformations are imposed within the nanofilaments, which result in notable differences in the density of the intermolecular hydrogen bond, determining the amount of adsorbed proteins. The adsorbed proteins can further induce interfilament entanglement of different degrees and patterns, which influences biodistribution and phagocytosis. The nanofilaments with tetrahydroxyproline segment exhibit diminish interfilament entanglement, phagocytosis, and improve circulation, biodistribution, and antitumor efficacy. These findings can deepen the understanding of nanofilament-protein interactions and filament-filament interactions as in the case of amyloid-β plaque, and facilitate the rational design of nanofilaments through peptide conformation control for chemical engineering and anticancer drug delivery.

Elucidating shape-mediated drug carrier mechanics of hematite nanomaterials for breast cancer therapeutics

Metallic nanomaterials have gained significant attention in cancer therapy as potential nanocarriers due to their unique properties at the nanoscale. However, nanomaterials face several drawbacks, including biocompatibility, stability, and cellular uptake. Hematite (α-Fe2O3) nanoparticles are emerging as promising nano-carriers to reduce adverse outcomes of conventional chemotherapeutics. However, the shape-mediated drug carrier mechanics of hematite nanomaterials are not raveled. In this study, we tailored hematite nanoparticles in ellipsoidal (EHNP) and spherical (SHNP) shapes with excellent biocompatibility and efficient drug encapsulation and release. We elucidate that EHNP exhibits higher cellular uptake than SHNP. With effective cellular internalization, the cisplatin-loaded EHNP showed excellent cytotoxicity with an IC50 value of 200 nM compared to the cisplatin-loaded SHNP. The flow cytometry cell sorting (FACS) analysis showed a four-fold increase in cell death by arresting the cells at the G0/G1 and G1 phases for cis-EHNP compared to cis-SHNP. The results show that ellipsoidal-shaped hematite nanoparticles can act as attractive nanocarriers with improved therapeutic efficacy in cancer therapy.

Nanotubes fabricated from a triple helix polysaccharide as a novel carrier delivering doxorubicin for breast cancer therapy

Most current strategies of drug delivery systems face momentous challenges owing to obvious biological barriers. It is urgently necessary to develop artificial nanocarriers with biological and physical properties to reduce the severe system cytotoxicity of chemical drugs. Herein, triggered by the stiffness and amphiphilicity of the triple helix β-glucan (LNT), we developed a novel nanocarrier with the hydrophobic cavity for delivering the anti-cancer drug of doxorubicin. In our findings, based on the law of minimum surface energy, LNT with considerable chain stiffness self-assembled into nanotubes (LNT-NT) with the controlled hydrophobic nanotube diameter at the nanometer level positively depending on the molecular weight through hydrogen bonding and hydrophobic interaction in manners of "shoulder-to-shoulder" and "head-to-head" arrangements. The hydrophobic drug of doxorubicin was then demonstrated to be entrapped into LNT-NT through hydrophobic interaction. Doxorubicin loaded into LNT-NT nanocarriers significantly inhibited tumor growth in vitro and in vivo by promoting tumor cell apoptosis and blocking cell proliferation, showing a higher therapeutic efficacy of 74.5 % and less adverse effects than the free doxorubicin, which was ascribed to the enhanced targetability by LNT-NT. In conclusion, this work proposes an alternative strategy for delivering hydrophobic drugs to reduce cytotoxicity and enhance therapeutic effectiveness by constructing β-glucan-based nanotubes as a promising nanocarrier.

Natural Small-Molecule-Based Carrier-Free Self-Assembly Library Originated from Traditional Chinese Herbal Medicine

The carrier-free self-assembly of small molecules opens a new window for the development of nanomaterials. This study is dedicated to developing binary small-molecular self-assemblies derived from phytochemicals in traditional Chinese herbal medicine. Among them, Rhei Radix et Rhizoma and Coptidis Rhizoma are a common pair used in clinics for thousands of years. Here, we found that there were numerous spherical supramolecular nanoparticles (NPs) originated from Rhei Radix et Rhizoma and Coptidis Rhizoma decoction. Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was used to analyze the composition of the supramolecules, and a total of 119 phytochemicals were identified (23 anthraquinones, 31 alkaloids, 24 organic acids, 8 tannins, and other components). Isothermal titration calorimetry (ITC) showed that the interaction between Rhei Radix et Rhizoma and Coptidis Rhizoma was a spontaneous exothermic reaction, indicating that their phytochemicals had the property of self-assembly and interacted to form supramolecules in the decocting process. Furthermore, scanning electron microscopy (SEM), UV, IR, NMR, and ITC were used to verify that rhein and coptisine could self-assemble into nanofibers (Rhe-Cop NFs), while emodin and coptisine could self-assemble into nanoparticles (Emo-Cop NPs). The formation mechanism analysis of the self-assemblies revealed that they were induced by electrostatic attraction, hydrogen bonding, and π-π stacking, forming nanospheres of about 50 nm and nanofibers. The current study not only provides an idea of discovering carrier-free self-assemblies from traditional herbal medicine decoction but also supplies a reference for the design of binary self-assembly of small molecules in the future.

Design and Validation of Nanofibers Made of Self-Assembled Peptides to Become Multifunctional Stimuli-Sensitive Nanovectors of Anticancer Drug Doxorubicin

Self-assembled peptides possess remarkable potential as targeted drug delivery systems and key applications dwell anti-cancer therapy. Peptides can self-assemble into nanostructures of diverse sizes and shapes in response to changing environmental conditions (pH, temperature, ionic strength). Herein, we investigated the development of self-assembled peptide-based nanofibers (NFs) with the inclusion of a cell-penetrating peptide (namely gH625) and a matrix metalloproteinase-9 (MMP-9) responsive sequence, which proved to enhance respectively the penetration and tumor-triggered cleavage to release Doxorubicin in Triple Negative Breast Cancer cells where MMP-9 levels are elevated. The NFs formulation has been optimized via critical micelle concentration measurements, fluorescence, and circular dichroism. The final nanovectors were characterized for morphology (TEM), size (hydrodynamic diameter), and surface charge (zeta potential). The Doxo loading and release kinetics were studied in situ, by optical microspectroscopy (fluorescence and surface-enhanced Raman scattering–SERS). Confocal spectral imaging of the Doxo fluorescence was used to study the TNBC models in vitro, in cells with various MMP-9 levels, the drug delivery to cells as well as the resulting cytotoxicity profiles. The results confirm that these NFs are a promising platform to develop novel nanovectors of Doxo, namely in the framework of TNBC treatment.

Supramolecular biomaterials for enhanced cancer immunotherapy

Cancer immunotherapy has achieved promising clinical results. However, many limitations associated with current cancer immunotherapy still exist, including low response rates and severe adverse effects in patients. Engineering biomaterials for...

Self-Assembling Peptides and Carbon Nanomaterials Join Forces for Innovative Biomedical Applications

Self-assembling peptides and carbon nanomaterials have attracted great interest for their respective potential to bring innovation in the biomedical field. Combination of these two types of building blocks is not trivial in light of their very different physico-chemical properties, yet great progress has been made over the years at the interface between these two research areas. This concise review will analyze the latest developments at the forefront of research that combines self-assembling peptides with carbon nanostructures for biological use. Applications span from tissue regeneration, to biosensing and imaging, and bioelectronics.

Lipophilicity, Pharmacokinetic Properties, and Molecular Docking Study on SARS-CoV-2 Target for Betulin Triazole Derivatives with Attached 1,4-Quinone

A key parameter in the design of new active compounds is lipophilicity, which influences the solubility and permeability through membranes. Lipophilicity affects the pharmacodynamic and toxicological profiles of compounds. These parameters can be determined experimentally or by using different calculation methods. The aim of the research was to determine the lipophilicity of betulin triazole derivatives with attached 1,4-quinone using thin layer chromatography in a reverse phase system and a computer program to calculate its theoretical model. The physiochemical and pharmacokinetic properties were also determined by computer programs. For all obtained parameters, the similarity analysis and multilinear regression were determined. The analyses showed that there is a relationship between structure and properties under study. The molecular docking study showed that betulin triazole derivatives with attached 1,4-quinone could inhibit selected SARS-CoV-2 proteins. The MLR regression showed that there is a correlation between affinity scoring values (ΔG) and the physicochemical properties of the tested compounds.