Instability of C60 fullerene interacting with lipid bilayer

Genetic treatment for autosomal dominant inherited retinal dystrophies: approaches, challenges and targeted genotypes

Inherited retinal diseases (IRDs) have been in the front line of gene therapy development for the last decade, providing a useful platform to test novel therapeutic approaches. More than 40 clinical trials have been completed or are ongoing, tackling autosomal recessive and X-linked conditions, mostly through adeno-associated viral vector delivery of a normal copy of the disease-causing gene. However, only recently has autosomal dominant (ad) disease been targeted, with the commencement of a trial for rhodopsin (RHO)-associated retinitis pigmentosa (RP), implementing antisense oligonucleotide (AON) therapy, with promising preliminary results (NCT04123626).Autosomal dominant RP represents 15%-25% of all RP, with RHO accounting for 20%-30% of these cases. Autosomal dominant macular and cone-rod dystrophies (MD/CORD) correspond to approximately 7.5% of all IRDs, and approximately 35% of all MD/CORD cases, with the main causative gene being BEST1 Autosomal dominant IRDs are not only less frequent than recessive, but also tend to be less severe and have later onset; for example, an individual with RHO-adRP would typically become severely visually impaired at an age 2-3 times older than in X-linked RPGR-RP.Gain-of-function and dominant negative aetiologies are frequently seen in the prevalent adRP genes RHO, RP1 and PRPF31 among others, which would not be effectively addressed by gene supplementation alone and need creative, novel approaches. Zinc fingers, RNA interference, AON, translational read-through therapy, and gene editing by clustered regularly interspaced short palindromic repeats/Cas are some of the strategies that are currently under investigation and will be discussed here.

Strong intramolecular hydrogen bonding in confined amino acids

Intramolecular hydrogen bonding is evaluated in three different amino acids encapsulated in C₆₀ fullerene in the context of electron density analysis. While conventional intramolecular hydrogen bonding in isolated amino acids are dominated by electrostatic character, it is shown that strong intramolecular hydrogen bonding can be formed in confined amino acids so that in two cases covalent intramolecular hydrogen bonding is appeared in the confined species. Also, results show that zwitterionic amino acids are stable in confined state, where no implicit or explicit solvation is applied. Covalent character for intramolecular hydrogen bonding in amino acids have not yet been reported.

Interacting Ru(bpy) 3 2 + Dye Molecules and TiO2 Semiconductor in Dye-Sensitized Solar Cells

Solar energy is an alternative source of energy that can be used to replace fossil fuels. Various types of solar cells have been developed to harvest this seemingly endless supply of energy, leading to the construction of solar cell devices, such as dye-sensitized solar cells. An important factor that affects energy conversion efficiency of dye-sensitized solar cells is the distribution of dye molecules within the porous semiconductor (TiO 2 ). In this paper, we formulate a continuum model for the interaction between the dye molecule Tris(2,2 ′ -bipyridyl)ruthenium(II) (Ru(bpy) 3 2 + ) and titanium dioxide (TiO 2 ) semiconductor. We obtain the equilibrium position at the minimum energy position between the dye molecules and between the dye and TiO 2 nanoporous structure. Our main outcome is an analytical expression for the energy of the two molecules as a function of their sizes. We also show that the interaction energy obtained using the continuum model is in close agreement with molecular dynamics simulations.

Ab initio study of C20 nanocluster effects on electrochemical properties of tetraphenylporphyrin

The Density Functional Theory (DFT) method was employed to study the properties of the C[Formula: see text] complex with tetraphenylporphyrin (TPP). Calculations were performed in vacuum and in the presence of different solvents. Strong interaction between the C[Formula: see text] cluster and TPP molecule was observed. To understand the effect of C[Formula: see text] on electrochemical properties of TPP, electron transfers from and toward the porphyrin and C[Formula: see text]-TPP complex were studied. It was shown that the presence of C[Formula: see text] influences the electron transfer reaction toward the porphyrin molecule and causes transfer of one and two electrons to C[Formula: see text]-porphyrin, which is more favorable compared with porphyrin alone. However, C[Formula: see text] has slight effect on electron transfer from porphyrin and on positive ion formation. The effect of solvent type on electron transfer energy was studied for these reactions, and it was shown that solvents with higher permittivity have lower electron transfer reaction energy, which may be predicted from ionic character of the products.

Quantification of C60-induced membrane disruption using a quartz crystal microbalance

Direct contact between fullerene C₆₀ nanoparticles (NPs) and cell membranes is one of mechanisms for its cytotoxicity. In this study, the influence of C₆₀ NPs on lipid membranes was investigated. Giant unilamellar vesicles (GUVs) were used as model cell membranes to observe the membrane disruption after C₆₀ exposure. C₆₀ NPs disrupted the positively charged GUVs but not the negatively charged vesicles, confirming the role of electrostatic forces. To quantify the C₆₀ adhesion on membrane and the induced membrane disruption, a supported lipid bilayer (SLB) and a layer of small unilamellar vesicles (SUVs) were used to cover the sensor of a quartz crystal microbalance (QCM). The mass change on the SLB (Δm_SLB) was caused by the C₆₀ adhesion on the membrane, while the mass change on the SUV layer (Δm_SUV) was the combined result of C₆₀ adhesion (mass increase) and SUV disruption (mass loss). The surface area of SLB (A_SLB) was much smaller than the surface area of SUV (A_SUV), but Δm_SLB was larger than Δm_SUV after C₆₀ deposition, indicating that C₆₀ NPs caused remarkable membrane disruption. Therefore a new method was built to quantify the degree of NP-induced membrane disruption using the values of Δm_SUV/Δm_SLB and A_SUV/A_SLB. In this way, C₆₀ can be compared with other types of NPs to know which one causes more serious membrane disruption. In addition, C₆₀ NPs caused negligible change in the membrane phase, indicating that membrane gelation was not the mechanism of cytotoxicity for C₆₀ NPs. This study provides important information to predict the environmental hazard presented by fullerene NPs and to evaluate the degree of membrane damage caused by different NPs.

Fullerene C₆₀ NPs adhere on lipid membrane due to electrostatic force and cause membrane disruption.

Instability of carbon nanoparticles interacting with lipid bilayers

For nanoparticles penetrating biological tissue, modelling indicates that without external forces, carbon nanoparticles will remain trapped in lipid bilayers.

Molecular structure, electronic property and vibrational spectroscopy of C24-glycine and Gd@C24-glycine complexes

Structure, electronic property and vibrational spectroscopy of C(24)-glycine and Gd@C(24)-glycine were systematically explored using the hybrid DFT-B3LYP functional. The interaction between empty C(24) cage and the smallest amino acid (glycine) was also investigated. It was found that the glycine molecule is energetically favorable to interact with the Mid-site on the C(24) cage through the amino nitrogen active site, rather than Top-site. The endohedral Gd atom increases the volume of the cage by around 6.7-9.8%. Analysis of frontier molecular orbitals reveals that the Gd@C(24)-glycine has the low-kinetic stability, being consistent with its thermodynamic property reflected by dissociation energy. We also see that the VIE and VEA of empty C(24) cage are slightly affected by absorbed glycine and endohedral Gd atom. Additionally, the assignments of simulated IR spectra are explored. The work may provide a theoretical reference for further application related structurally to potential antitumour activity.