Immunotherapy is a clinically effective method for treating tumors. Manganese can activate the cGAS-STING signaling pathway and induce an anti-tumor immune response. However, its efficacy is hindered by non-specific distribution and low uptake rates.
View Article and Find Full Text PDFBrain disorders represent a significant challenge in medical science due to the formidable blood-brain barrier (BBB), which severely limits the penetration of conventional therapeutics, hindering effective treatment strategies. This review delves into the innovative realm of biomimetic nanodelivery systems, including stem cell-derived nanoghosts, tumor cell membrane-coated nanoparticles, and erythrocyte membrane-based carriers, highlighting their potential to circumvent the BBB's restrictions. By mimicking native cell properties, these nanocarriers emerge as a promising solution for enhancing drug delivery to the brain, offering a strategic advantage in overcoming the barrier's selective permeability.
View Article and Find Full Text PDFTwo series of 2,4-diarylaminopyrimidine derivatives containing sulfonamide moiety were designed and synthesized for screening as inhibitors of focal adhesion kinase (FAK). Most compounds significantly inhibited the enzymatic activities of FAK, and the best compound was 7b (IC = 0.27 nM).
View Article and Find Full Text PDFThe rapid deprotonation of G˙ in the DNA strand impedes positive charge (hole) transfer, whereas the slow deprotonation rate of G˙ in the G-tetrad makes it a more suitable carrier for hole conduction. The QM/MM(ABEEM) combined method, which involves the integration of QM and the ABEEM polarizable force field (ABEEM PFF), was developed to investigate the deprotonation of neutral and cation free radicals in the G-tetrad and GGX(8-oxo-G) tetrad (xanthine and 8-oxoguanine dual substituted G-tetrad). By incorporating valence-state electronegativity piecewise functions *() and implementing charge local conservation conditions, QM/MM(ABEEM) possesses the advantage of accurately simulating charge transfer and polarization effect during deprotonation.
View Article and Find Full Text PDFOral diseases are usually caused by inflammation and bacterial infection. Reactive oxygen species (ROS), which come from both autologous inflammation tissue and bacterial infection, play an important role in this process. Thus, the elimination of excessive intracellular ROS can be a promising strategy for anti-inflammatory treatment.
View Article and Find Full Text PDFRNA folding prediction is very meaningful and challenging. The molecular dynamics simulation (MDS) of all atoms (AA) is limited to the folding of small RNA molecules. At present, most of the practical models are coarse grained (CG) model, and the coarse-grained force field (CGFF) parameters usually depend on known RNA structures.
View Article and Find Full Text PDFThe approved small-molecule inhibitors of anaplastic lymphoma kinase (ALK) have shown remarkable efficacy in some subset of cancer patients. However, the numerous ALK mutants or fusion partners are resistant to such drugs, greatly limiting their application in clinic. Despite the drug design strategy of proteolysis-targeting chimera (PROTAC) holds great potential to overcome drug resistance in theory, there are obvious disadvantages for the reported PROTACs that include high molecular weight, long linkers, difficult synthesis routes as well as insufficient evidence in activity for diverse ALK mutants.
View Article and Find Full Text PDFFront Bioeng Biotechnol
October 2022
As a highly pathogenic avian influenza virus, influenza A (H5N1) has been reported to infect humans, posing a major threat to both poultry industry and public health. It is an urgent need to develop a kind of effective vaccine to prevent death and reduce the incidence rate of H5N1 avian influenza. Compared with traditional inactivated or attenuated vaccines, deoxyribonucleic (DNA) vaccines have the advantages of continuously expressing plasmid-encoded antigens and inducing humoral and cellular immunity.
View Article and Find Full Text PDFJ Phys Chem Lett
October 2022
RNA folding prediction is a challenge. Currently, many RNA folding models are coarse-grained (CG) with the potential derived from the known RNA structures. However, this potential is not suitable for modified and entirely new RNA.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2022
Bioresponsive nanomaterials are increasingly important in a variety of applications such as disease imaging, drug delivery, and tissue engineering. However, it remains a big challenge to manipulate response efficacy of such materials for performance optimization in a highly complex milieu in vivo. Here, we developed chemically adjustable nanoreactors (CANs) with the structure of polymeric cores and albumin shells to achieve tunable redox responsivity.
View Article and Find Full Text PDFLipid-membrane-targeting strategies hold great promise to develop broad-spectrum antivirals. However, it remains a big challenge to identify novel membrane-based targets of viruses and virus-infected cells for development of precision targeted approaches. Here, it is discovered that viroporins, viral-encoded ion channels, which have been reported to mediate release of hydrogen ions, trigger membrane acidification of virus-infected cells.
View Article and Find Full Text PDFManganese has recently been exploited for cancer immunotherapy, fenton-like reaction-mediated chemo-dynamic therapy, and magnetic resonance imaging. The integration of multiple roles of manganese into one platform is of great significance for cancer theranostics and tumor inhibition. Here, we designed a multifunctional nanoplatform based on manganese, which consisted of a manganese-containing inner core and a phospholipid bilayer shell co-loaded with glucose oxidase (GOx), paclitaxel (PTX), and a NIR fluorescent dye (NanoMn-GOx-PTX).
View Article and Find Full Text PDFUnlabelled: Interferon (IFN) responses are central to host defense against coronavirus and other virus infections. Manganese (Mn) is capable of inducing IFN production, but its applications are limited by nonspecific distributions and neurotoxicity. Here, we exploit chemical engineering strategy to fabricate a nanodepot of manganese (nanoMn) based on Mn.
View Article and Find Full Text PDFBarium is a potent blocker of the KcsA potassium channel. A strategy using x-ray crystallography and molecular dynamics (MD) simulation has been used to understand this phenomenon as described in Rohaim et al. [1].
View Article and Find Full Text PDFBarium (Ba) is a classic permeant blocker of potassium (K) channels. The "external lock-in effect" in barium block experiments, whereby the binding of external K impedes the forward translocation of the blocker, provides a powerful avenue to investigate the selectivity of the binding sites along the pore of potassium channels. Barium block experiments show that the external lock-in site is highly selective for K over Na.
View Article and Find Full Text PDFBased on the atom-bond electronegativity equalization method fused into molecular mechanics (ABEEM/MM), two fluctuating charge models of OH-water system were proposed. The difference between these two models is whether there is charge transfer between OH and its first-shell water molecules. The structures, charge distributions, charge transfer, and binding energies of the OH(HO) ( = 1-8, 10, 15, 23) clusters were studied by these two ABEEM/MM models, the OPLS/AA force field, the OPLS-SMOOTH/AA force field, and the QM methods.
View Article and Find Full Text PDFChemotherapy post cancer surgery has important clinical significance for reducing the chance of recurrent-metastasis. However, postoperative chemotherapy efficacy is hampered by poor targeting capability and dose-limiting toxicity of chemo-drugs. Herein, we report a bio-mimetic platelet membrane-cloaked paclitaxel nanocrystal system (PPNCs), which consists of spherical paclitaxel nanocrystals (PNCs) as a high-dose drug core, polyethylene glycol-conjugated paclitaxel (PEG-PTX) as an amphiphilic molecule to adjust the surface hydrophilicity of PNCs and the shell of platelet membrane that can target surgical coagulation site.
View Article and Find Full Text PDFRecent decades have witnessed several nanocrystal-based hydrophobic drug formulations because of their excellent performance in improving drug loading and controlling drug release as mediate drug forms in tablets or capsules. However, the intravenous administration of drug nanocrystals was usually hampered by their hydrophobic surface properties, causing short half-life time in circulation and low drug distribution in tumor. Here, we proposed to enclose nanocrystals (NC) of hydrophobic drug, such as paclitaxel (PTX) into erythrocyte membrane (EM).
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2019
In an attempt to develop an imaging probe with ultra-high sensitivity for a broad range of tumors in vivo and inspired by the concept of chemical synthetic nanoreactors, we designed a type of glutathione-priming fluorescent nanoreactor (GPN) with an albumin-coating shell and hydrophobic polymer core containing disulfide bonds, protonatable blocks, and indocyanine green (ICG), a near-infrared fluorophore. The albumin played multiple roles including biocompatible carriers, hydrophilic stabilizer, "receptor" of the fluorophores, and even targeting molecules. The protonation of the hydrophobic core triggered the outside-to-core transport of acidic glutathione (GSH), as well as the core-to-shell transference of ICGs after the disulfide bond cleavage by GSH, which induced strong binding of fluorophores with albumins on the GPN shell, initiating intensive fluorescence signals.
View Article and Find Full Text PDFNitrosylation reaction mechanisms of the hydrolysates of NAMI-A and hydrolysis reactions of ruthenium nitrosyl complexes were investigated in the triplet state and the singlet state. Activation free energies were calculated by combining the QM/MM(ABEEM) method with free energy perturbation theory, and the explicit solvent environment was simulated by an ABEEMσπ polarizable force field. Our results demonstrate that nitrosylation reactions of the hydrolysates of NAMI-A occur in both the triplet and the singlet states.
View Article and Find Full Text PDFTetra-amido macrocyclic ligand (TAML) activator is a functional analog of peroxidase enzymes, which activates hydrogen peroxide (HO) to form high valence iron-oxo complexes that selectively degrade persistent aromatic organic contaminants (ACs) in water. Here, we develop quantitative structure-activity relationship (QSAR) models based on measured pseudo first-order kinetic rate coefficients (k) of 29 ACs (e.g.
View Article and Find Full Text PDFThe structural polymorphism of the oxygen-evolving complex is of great significance to photosynthetic water oxidation. Employing density functional theory calculations, we have made further advisement on the interconversion mechanism of O5 transfer in the S state, mainly focusing on the potentiality of multi-state reactivity and spin transitions. Then, O5 protonation is proven impossible in S for irreversibility of the interconversion, which serves as an auxiliary judgment for the protonation state of O5 in S.
View Article and Find Full Text PDFThe dioxygen formation mechanism of biological water oxidation in nature has long been the focus of argument; many diverse mechanistic hypotheses have been proposed. Based on a recent breakthrough in the resolution of the electronic and structural properties of the oxygen-evolving complex in the S state, our density functional theory (DFT) calculations reveal that the open-cubane oxo-oxyl coupling mechanism, whose substrates preferably originate from W2 and O5 in the S state, emerges as the best candidate for O-O bond formation in the S state. This is justified by the overwhelming energetic superiority of this mechanism over alternative mechanisms in both the isomeric open and closed-cubane forms of the MnCaO cluster; spin-dependent reactivity rooted in variable magnetic couplings was found to play an essential role.
View Article and Find Full Text PDFDNA damage caused by oxidized bases can lead to aging and cancer in living beings. Luckily, a repair enzyme is able to repair the oxidized bases. The key step is to accurately recognize the oxidized bases, which mainly rely on complex hydrogen bond interactions.
View Article and Find Full Text PDFAmmonia as a water analogue can bind to the MnCaO cluster of the oxygen-evolving complex in concomitance with ligand substitution and underlying structural transformation. On account of current controversies of the binding site and the absence of the viewpoint of reactivity and mechanistic proofs, we have investigated three modes of NH binding based on our elaborations of the possible reaction mechanisms, in correspondence with experimental observation for the NH-altered g ≈ 2.0 EPR multiline signal.
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