A Density Functional Theory Study on the Interaction Between 5-Fluorouracil Drug and C24 Fullerene

Size-Dependent Fullerenes for Enhanced Interaction of l-Leucine: A Combined DFT and MD Simulations Approach

Fullerene-based biosensors have received great attention due to their unique electronic properties that allow them to transduce electrical signals by accepting electrons from amino acids. Babies with MSUD (maple syrup urine disease) are unable to break down amino acids such as l-leucine, and excess levels of the l-leucine are harmful. Therefore, sensing of l-leucine is foremost required. We aim to investigate the interaction tendencies of size-variable fullerenes (CX; X = 24, 36, 50, and 70) toward l-leucine (LEU) using density functional theory (DFT-D3) and classical molecular dynamics (MD) simulation. The C24 fullerene shows the highest affinity of the LEU biomolecule in the gas phase. Smaller fullerenes (C24 and C36) show stronger interactions with leucine due to their higher curvature in water environments. Moreover, recovery times in the ranges of 1010 and 104 s make it a viable candidate for the isolation application of LEU from the biological system. Further, the interaction between LEU and fullerenes is in line with the natural bond order (NBO) analysis, Mulliken charge analysis, quantum theory atom in molecule (QTAIM) analysis, and reduced density gradient (RDG) analysis. At 310 K, employing the explicit water model in classical MD simulations, fullerenes C24 and C36 demonstrate notably elevated binding free energies (-24.946 kJ/mol) in relation to LEU, showcasing their potential as sensors for l-leucine. Here, we demonstrate that the smaller fullerene exhibits a higher potential for l-leucine sensors than the larger fullerene.

In silico investigation on interaction of small Ag6 nano-particle cluster with tyramine neurotransmitter

The interaction of tyramine neurotransmitter with silver nano-particle (Ag6) cluster is explored in terms of the molecular structure, electronic properties and NBO analysis of tyramine-AgNPs bio-molecular conjugate. The adsorption mechanism of tyramine onto the Ag6 cluster has been investigated through computing of the electronic and geometrical properties in addition to the adsorption energies in various possible configurations. The magnitude of adsorption energy corresponding to the most favorable tyramine-Ag6 bio-molecular conjugate has been computed to be - 14.36 kcal/mol in the gas phase, which infers a good adsorption of tyramine with AgNPs cluster suggesting the practical applications of tyramine-AgNPs bio-molecular conjugates in bio-sensing, drug delivery, bio-imaging and other applications. Different electronic properties such as the energy gap of HOMO-LUMO, Fermi level and work function have been investigated in detail. Moreover, the effect of aqueous media on adsorption energy and electronic properties of the most favorable tyramine-AgNPs bio-molecular conjugate is investigated in order to understand the impact of the real biological situation.

DFT investigation of temozolomide drug delivery by pure and boron doped C24 fullerene-like nanocages

In this paper, the DFT/M05-2X-D3/6-31+G(d,p) theoretical chemistry method is used to probe the adsorption ability of pure and boron doped C24 toward the temozolomide (TMZ) anticancer drug. The study is conducted in both gas and aqueous phases. The positive values of the Gibbs free energy of formation (12.03, 9.14 and 2.51 kcal mol-1) show that the adsorption of TMZ on C24 is not allowed. However, the boron-doped C24 (BC23) forms a very stable molecular complex with TMZ in the gas phase, characterized by the adsorption energy and Gibbs free energy values of -32.07 and -21.27 kcal mol-1 respectively. Analysis of Hirshfeld's atomic charge revealed the transfer of 0.6395e from TMZ to BC23, which is confirmed by the value of the dipole moment of the complex (13.42 D in the gas phase) as well as its molecular electrostatic potential map. The change in the frontier molecular orbital energy difference of BC23 is found to be 21.67% proving the good sensitivity of the cage toward the drug. The TMZ-BC23 molecular complex is very stable in water though the sensitivity of the cage is hugely reduced in that solvent. The reliability of these results was confirmed by checking the outcomes at both wB97XD/6-31+G(d,p) and B3LYP-D3/6-31+G(d,p) levels. This work shows that pristine BC23 is a better adsorbent of TMZ than some reported nanomaterials from the theoretical chemistry point of view.

Optical properties of nanostructured antiviral and anticancer drugs

We present a computational study on the optical absorption properties of some systems of interest in the field of drug delivery. In particular we considered as drug molecules favipiravir (T705, an antiviral molecule) and 5-fluorouracil (5FU, an anticancer molecule) and, on the other hand, pure fullerenes (C24, B12N12, Ga12N12) and doped fullerenes (C23B, CB11N12) are considered as nanocarriers. Some combined configurations between the drug molecules and the carrier nanostructures have been then studied. The optical absorption properties of the above mentioned drug molecules and their carrier nanostructures in the free and bound states are obtained by a TD-DFT method, in gas phase and in aqueous solution. We perform a detailed analysis of the modifications arising in the absorption spectra that take place in some linked configurations between the drug molecules and the carrier nanostructures. These changes could be of importance as an optical fingerprint of the realized drug/carrier link.

In situ synthesis of polythiophene encapsulated 2D hexagonal boron nitride nanocomposite based electrochemical transducer for detection of 5-fluorouracil with high selectivity

It is difficult for the scientific community to develop a nonenzymatic sensing platform for extremely sensitive and selective detection of specific biomolecules, antibiotics, food adulterants, heavy metals, etc. One of the most significant chemotherapy drugs, 5-fluorouracil (5-Fu), which is used to treat solid malignancies, has a fluorine atom in the fifth position of the uracil molecule. Recognizing the secure and effective dosing of drugs for chemotherapy continues to be a critical concern in cancer disease management. The maintenance of the optimal 5-Fu concentration is dependent on the presence of 5-Fu in biofluids. Herein we reported a conducting polymer encapsulated 2D material, PTh/h-BN for the efficient electrochemical detection of anticancer drug 5-Fu. Furthermore, the synthesized PTh/h-BN nanocomposite was confirmed by the High-Resolution Transmission Electron Microscope (HR-TEM), High-Resolution Scanning Electron Microscope (HR-SEM), X-ray diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FT-IR). The electrical resistance of PTh/h-BN modified GCE and its sensing performance towards 5-Fu were tested using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV) studies respectively. The analytical performance of our proposed catalyst was tested using Differential Pulse Voltammetry (DPV), and the amperometry (i-t curve) method. From the results, our proposed PTh/h-BN nanocomposite-modified GCE shows enhanced sensing performance due to higher redox peak currents, large active surface area, and high electrical conductivity. Moreover, the nanohybrid shows enhanced sensing performances with quick response time, wide linear range, the lowest limit of detection, high sensitivity, and high selectivity in the presence of various interferents. Finally, the practical applicability of the proposed sensor was tested with real-world samples with very good recovery percentages.

Exploring the adsorption ability with sensitivity and reactivity of C12-B6N6, C12-Al6N6, and B6N6-Al6N6 heteronanocages towards the cisplatin drug: a DFT, AIM, and COSMO analysis

The DFT study on the adsorption behaviour of the C24, B12N12, and Al12N12 nanocages and their heteronanocages towards the anticancer drug cisplatin (CP) was performed in gas and water media. Among the three pristine nanocages, Al12N12 exhibited high adsorption energy ranging from -1.98 to -1.63 eV in the gas phase and -1.47 to -1.39 eV in water media. However, their heterostructures C12-Al6N6 and B6N6-Al6N6 showed higher interaction energies (-2.22 eV and -2.14 eV for C12-Al6N6 and B6N6-Al6N6) with a significant amount of charge transfer. Noteworthy variations in electronic properties were confirmed by FMO analysis and DOS spectra analysis after the adsorption of the cisplatin drug on B12N12 and B6N6-Al6N6 nanocages. Furthermore, an analysis of quantum molecular descriptors unveiled salient decrement in global hardness and increments in electrophilicity index and global softness occurred after the adsorption of CP on B12N12 and B6N6-Al6N6. On the other hand, the above-mentioned fluctuations are not so noteworthy in the case of the adsorption of CP on Al12N12, C12-B6N6, and C12-Al6N6. Concededly, energy calculation, FMO analysis, ESP map, DOS spectra, quantum molecular descriptors, dipole moment, COSMO surface analysis, QTAIM analysis, and work function analysis predict that B12N12 and B6N6-Al6N6 nanocages exhibit high sensitivity towards CP drug molecules.

Theoretical study of the interaction of fullerenes with the emerging contaminant carbamazepine for detection in aqueous environments

The global increase in drug consumption exposes the growing need to develop new systems for the detection, capture, and treatment of bioactive molecules. Carbamazepine is one instance of such contaminants at the top of the ranking commonly found in sewage treatment systems. This work, therefore, presents a theoretical study of fullerene C₆₀ and its derivatives with substitutional doping with B, Al, Ga, Si, Ge, N and P, for the detection and capture of carbamazepine is aqueous medium. Solvation effects were included by means of the Polarizable Continuum Solvent method. The results indicate that doped fullerenes are sensitive for the detection of carbamazepine both in gaseous and aquatic environments. Investigation on the intermolecular interactions between the drug and the fullerene molecule were carried out, allowing the characterization of the interactions responsible for stabilizing the adsorption of carbamazepine to the fullerenes. The theoretical survey revealed that fullerenes doped with Al, Ga, Si and Ge chemically adsorb carbamazepine whereas for the case of fullerenes doped with other heteroatoms physisorption is responsible for the molecular recognition. Relying on DFT calculations, the fullerene derivatives C₅₉Al, C₅₉Si and C₅₉Ga are the most suitable to act both as a sensor and to uptake carbamazepine in aquatic environments.

Alkali metal decorated C60 fullerenes as promising materials for delivery of the 5-fluorouracil anticancer drug: a DFT approach

The development of effective drug delivery vehicles is essential for the targeted administration and/or controlled release of drugs. Using first-principles calculations, the potential of alkali metal (AM = Li, Na, and K) decorated C60 fullerenes for delivery of 5-fluorouracil (5FU) is explored. The adsorption energies of the 5FU on a single AM atom decorated C60 are -19.33, -16.58, and -14.07 kcal mol-1 for AM = Li, Na, and K, respectively. The results, on the other hand, show that up to 12 Li and 6 Na or K atoms can be anchored on the exterior surface of the C60 fullerene simultaneously, each of which can interact with a 5FU molecule. Because of the moderate adsorption energies and charge-transfer values, the 5FU can be simply separated from the fullerene at ambient temperature. Furthermore, the results show that the 5FU may be easily protonated in the target cancerous tissues, which facilitates the release of the drug from the fullerene. The inclusion of solvent effects tends to decrease the 5FU adsorption energies in all 5FU-fullerene complexes. This is the first report on the high capability of AM decorated fullerenes for delivery of multiple 5FU molecules utilizing a C60 host molecule.

Theoretical investigation of favipiravir antiviral drug based on fullerene and boron nitride nanocages

Smart implementation of novel advanced nanocarriers such as functionalized C₂₄ and B₁₂N₁₂ nanocages is used supplement for antiviral activity 5-Fluoro-2-hydroxypyrazine-3-carboxamide (Favipiravir; Avigan; T-705), as treatment of COVID-19. The interaction energies of Favipiravir with perfect (B₁₂N₁₂ and C₂₄) and doped (BC₂₃ and CB₁₁N₁₂) nanocages were studied at temperatures equal to 310.15 K and 298.15 K using DFT. Our results have shown that the interaction of the Favipiravir (C[bond, double bond]O group) with BC₂₃ and CB₁₁N₁₂ is more favorable than with the C₂₄ and B₁₂N₁₂ nanocages in the gas and aqueous environments. Additionally, the natural bond orbital, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), energy gap, chemical reactivity, molecular electrostatic potential, and thermodynamic parameters of the optimized structure have been examined. Furthermore, the UV-Vis and infrared spectroscopy have been evaluated for the investigation of the molecular orbitals Participated in the absorption spectrum of the Favipiravir before and after the interaction with the C₂₄, BC₂₃, B₁₂N_12, and CB₁₁N₁₂, sites at maximum wavelength utilizing the time-dependent density functional theory (TD-B3LYP and TD-CAM-B3LYP). The intermolecular interactions have been analyzed by non-covalent interactions (NCI) and also, the electron localization function (ELF) is discussed.

The recent advancement of low-dimensional nanostructured materials for drug delivery and drug sensing application: A brief review

In this review article, we have presented a detailed analysis of the recent advancement of quantum mechanical calculations in the applications of the low-dimensional nanomaterials (LDNs) into biomedical fields like biosensors and drug delivery systems development. Biosensors play an essential role for many communities, e.g. law enforcing agencies to sense illicit drugs, medical communities to remove overdosed medications from the human and animal body etc. Besides, drug delivery systems are theoretically being proposed for many years and experimentally found to deliver the drug to the targeted sites by reducing the harmful side effects significantly. In current COVID-19 pandemic, biosensors can play significant roles, e.g. to remove experimental drugs during the human trials if they show any unwanted adverse effect etc. where the drug delivery systems can be potentially applied to reduce the side effects. But before proceeding to these noble and expensive translational research works, advanced theoretical calculations can provide the possible outcomes with considerable accuracy. Hence in this review article, we have analyzed how theoretical calculations can be used to investigate LDNs as potential biosensor devices or drug delivery systems. We have also made a very brief discussion on the properties of biosensors or drug delivery systems which should be investigated for the biomedical applications and how to calculate them theoretically. Finally, we have made a detailed analysis of a large number of recently published research works where theoretical calculations were used to propose different LDNs for bio-sensing and drug delivery applications.

Fullerene C24 as a potential carrier of ephedrine drug - a computational study of interactions and influence of temperature

Interactions between fullerene C₂₄ and a frequently used supplement for sport activities, ephedrine (EPH), have been studied in detail by a combination of density functional theory (DFT), time dependent DFT (TD-DFT) calculations, the symmetry-adapted perturbation theory (SAPT) approach and molecular dynamics (MD) simulations. Information about interaction energies and non-covalent interactions formed between C₂₄ and EPH have been obtained by DFT calculations. TD-DFT calculations have been used in order to obtain UV/vis spectra and to check whether the presence of the EPH molecule produces significant changes in the spectrum. The SAPT approach has been employed in order to decompose the interaction energy into components and therefore to better understand the physical origins of interaction between C₂₄ and EPH. Last, but not least, MD simulations have been used in order to track the influence of temperature on the interactions between C₂₄ and EPH.