DNA-induced fusion between lipid domains of peptide-lipid hybrid vesicles.

Peptide-lipid hybrid vesicles were prepared with complementary DNA strands in their lipid domains. Hybridization of the complementary DNA strands induced the controlled fusion of the vesicles during repeated heating and cooling cycles. Vesicle fusion was indicated by a decrease in the efficiency of Förster resonance energy transfer between lipid-localized probes (from 72 to 42%) and transmission electron microscopy analysis. We suggest that this approach is a general strategy for the creation of polymersomes with membrane-fusion functionality.

Potential antiviral properties of antiplatelet agents against SARS-CoV-2 infection: an in silico perspective.

SARS-CoV-2 represents the causative agent of the current pandemic (COVID-19). The drug repurposing technique is used to search for possible drugs that can bind to SARS-CoV-2 proteins and inhibit viral replication. In this study, the FDA-approved antiplatelets are tested against the main protease and spike proteins of SARS-CoV-2 using in silico methods. Molecular docking and molecular dynamics simulation are used in the current study. The results suggest the effectiveness of vorapaxar, ticagrelor, cilostazol, cangrelor, and prasugrel in binding the main protease (Mpro) of SARS-CoV-2. At the same time, vorapaxar, ticagrelor, and cilostazol are the best binders of the spike protein. Therefore, these compounds could be successful candidates against COVID-19 that need to be tested experimentally.

Tubular Assembly Formation Induced by Leucine Alignment along the Hydrophobic Helix of Amphiphilic Polypeptides.

The introduction of α-helical structure with a specific helix-helix interaction into an amphipathic molecule enables the determination of the molecular packing in the assembly and the morphological control of peptide assemblies. We previously reported that the amphiphilic polypeptide SL12 with a polysarcosine (PSar) hydrophilic chain and hydrophobic α-helix (l-Leu-Aib)6 involving the LxxxLxxxL sequence, which induces homo-dimerization due to the concave-convex interaction, formed a nanotube with a uniform 80 nm diameter. In this study, we investigated the importance of the LxxxLxxxL sequence for tube formation by comparing amphiphilic polypeptide SL4A4L4 with hydrophobic α-helix (l-Leu-Aib)2-(l-Ala-Aib)2-(l-Leu-Aib)2 and SL12. SL4A4L4 formed spherical vesicles and micelles. The effect of the LxxxLxxxL sequence elongation on tube formation was demonstrated by studying assemblies of PSar-b-(l-Ala-Aib)-(l-Leu-Aib)6-(l-Ala-Aib) (SA2L12A2) and PSar-b-(l-Leu-Aib)8 (SL16). SA2L12A2 formed nanotubes with a uniform 123 nm diameter, while SL16 assembled into vesicles. These results showed that LxxxLxxxL is a necessary and sufficient sequence for the self-assembly of nanotubes. Furthermore, we fabricated a double-layer nanotube by combining two kinds of nanotubes with 80 and 120 nm diameters-SL12 and SA2L12A2. When SA2L12A2 self-assembled in SL12 nanotube dispersion, SA2L12A2 initially formed a rolled sheet, the sheet then wrapped the SL12 nanotube, and a double-layer nanotube was obtained.

Hypoxia-responsive pullulan-based nanoparticles as erlotinib carriers.

A hypoxia-responsive pullulan-based co-polymer was developed to assess its efficacy to deliver erlotinib (ERL) to the cervical cancer cells. Upon exposure to hypoxic condition, the synthesized and structurally characterized co-polymer i.e. succinyl pullulan-g-6-(2-nitroimidazole) hexylamine (Pull-SA-HA-NI) exhibited a hypochromic shift in the UV spectra and alteration in its self-assembled structures as compared to the control co-polymer, succinyl pullulan-g-hexylamine (Pull-SA-HA). Its corresponding ERL-loaded nanoparticles (NPs) displayed an attenuated crystallinity of pure ERL with excellent drug-trapping capacity (DEE, 94.23 ± 1.36%) and acceptable zeta potential (+39.21 ± 1.09 mV) and diameter (84.10 ± 2.10 nm) values. These also evidenced a faster drug release profile under hypoxic condition relative to the normoxic condition. The cellular internalization of the NPs was mediated through the energy-dependent endocytic process, which could utilize its multiple pathways (i.e., macropinocytosis, clathrin- and caveolae-mediated endocytosis). The ERL-loaded NPs suppressed HeLa cell proliferation and induced apoptosis more efficiently than the pristine drug.

Etherified pullulan-polyethylenimine based nanoscaffolds improved chemosensitivity of erlotinib on hypoxic cancer cells.

The current research endeavor aimed to accomplish hypoxia-responsive polyethyleneimine-conjugated carboxymethyl pullulan-based co-polymer (CMP-HA-NI-PEI-NBA) bearing nitroaromatic subunits to efficiently deliver erlotinib (ERL) to reverse its hypoxia-induced resistance in cancer cells. As compared to a control co-polymer (CMP-HA-MI-PEI-BA) devoid of hypoxia-sensitive moieties, this scaffold demonstrated a hypochromic shift in the UV spectra and rapid dismantling of its self-assembled architecture upon exposure to simulated hypoxic condition. The hypoxia-responsive co-polymer encapsulated ERL with desirable loading capacity (DEE, 63.05 ± 2.59%), causing attenuated drug crystallinity. The drug release rate of the scaffold under reducing condition was faster relative to that of non-reducing environment. Their cellular uptake occurred through an energy-dependent endocytic process, which could exploit its caveolae/lipid raft-mediated internalization pathway. The ERL-loaded scaffolds more efficiently induced apoptosis and suppressed the proliferation of drug-resistant hypoxic HeLa cells than the pristine ERL. Hence, this study presented a promising drug delivery nanoplatform to overcome hypoxia-evoked ERL resistance.

Differential mechanisms of autophagy in cancer stem cells: Emphasizing gastrointestinal cancers.

Gastrointestinal (GI) cancers are one of the most common forms of malignancies and still are the most important cause of cancer-related mortality worldwide. Autophagy is a conserved catabolic pathway involving lysosomal degradation and recycling of whole cellular components, which is essential for cellular homeostasis. For instance, it acts as a pivotal intracellular quality control and repair mechanism but also implicated in cell reformation during cell differentiation and development. Indeed, GI cancer stem cells (CSCs) are thought to be responsible for tumour initiation, traditional therapies resistance, metastasis and tumour recurrence. Molecular mechanisms of autophagy in normal vs CSCs gain great interest worldwide. Here, we shed light on the role of autophagy in normal stem cells differentiation for embryonic progression and its role in maintaining the activity and self-renewal capacity of CSCs which offer novel viewpoints on promising cancer therapeutic strategies based on the differential roles of autophagy in CSCs.

Superiority of cilostazol among antiplatelet FDA-approved drugs against COVID 19 Mpro and spike protein: Drug repurposing approach.

Coronavirus disease 2019 (COVID 19) was first identified in Wuhan, China near the end of 2019. To date, COVID-19 had spread to almost 235 countries and territories due to its highly infectious nature. Moreover, there is no vaccine or Food and Drug Administration (FDA)-approved drug. More time is needed to establish one of them. Consequently, the drug repurposing approach seems to be the most attractive and quick solution to accommodate this crisis. In this regard, we performed molecular docking-based virtual screening of antiplatelet FDA-approved drugs on the key two viral target proteins: main protease (Mpro ) and spike glycoprotein (S) as potential inhibitor candidates for COVID-19. In the present study, 15 antiplatelet FDA-approved drugs were investigated against the concerned targets using the Molecular Docking Server. Our study revealed that only cilostazol has the most favorable binding interaction on Mpro (PDB ID: 6LU7) and cilostazol, iloprost, epoprostenol, prasugrel, and icosapent ethyl have a higher binding affinity on spike glycoprotein (S) (PDB ID: 6VYB) compared with recent anti-CoVID-19. Therefore, cilostazol is a promising FDA drug against COVID-19 by inhibiting both Mpro and S protein. The insights gained in this study may be useful for quick approach against COVID-19 in the future.

Association between a novel G94A single nucleotide polymorphism in ATP1A1 gene and type 2 diabetes mellitus among Egyptian patients.

BACKGROUND: Na+/K+ ATPase enzyme is essential for nerve cell membrane integrity, and reduction in its activity, probably due to ATP1A1 gene polymorphisms, is related to diabetic neuropathy progression. Therefore, the goal of the existent study is to evaluate the Na+/K+ ATPase activity in type 2 diabetes mellitus (T2DM) Egyptian patients with or without neuropathy, search for polymorphism(s) in the highly polymorphic region of ATP1A1 gene, exon 2, and study its (their) associations with T2DM with and without neuropathy. MATERIALS AND METHODS: A total number of 150 individuals were subclassified into healthy controls (n = 30), T2DM without complications (n = 60), and T2DM with neuropathy (n = 60). RESULTS: The biochemical results exhibited a significant reduction in fasting C-Peptide and activity of Na+/K+ ATPase in T2DM patients with neuropathy followed by T2DM without complication in comparison with healthy controls. ATP1A1 exon2 was amplified by polymerase chain reaction (PCR) then digested by the PstI restriction enzyme, and the obtained data from restriction fragment length polymorphism-PCR and sequencing revealed the existence of a novel synonymous G94A single nucleotide polymorphism (SNP) at nucleotide 27 in exon 2 of ATP1A1 gene (rs1060366). Diabetic groups had only allele A, while the control group had G allele. Interestingly, individuals carrying AA genotype had a significantly lower Na+/K+ ATPase, C-peptide, and higher glycosylated hemoglobin (HBA1c %) than those having GG genotype, suggesting a possible association for this SNP, and this developed phenomenon of not only T2DM but also diabetic neuropathy. CONCLUSION: Thus, allele A of G94A SNP (rs1060366) could be a risk allele for diabetes susceptibility among Egyptian patients.