PAMAM and polyester dendrimers as favipiravir nanocarriers: a comparative study using DFT method

Preparation and evaluation in vitro release of sodium alginate/chitosan polyelectrolyte microparticles containing rifampicin and theoretical study using DFT methods

In this work, rifampicin-loaded sodium alginate/chitosan polyelectrolyte microparticles were prepared by the ionotropic gelation technique using CaCl2 as a cross-linking agent. The influence of different sodium alginate and chitosan concentrations on particle size, surface properties, and in vitro release behavior was studied. An infrared spectroscopy investigation verified the lack of any drug-polymer interaction. The microparticles prepared using (30, 50) mg of sodium alginate were spherical while when using 75 mg of sodium alginate, vesicles with round heads and tapered tails were formed. The results showed that the microparticle diameters were between (11.872-35.3645) µm. The amount of rifampicin released and the kinetics of drug release from microparticles were studied, and the results showed that by increasing the concentration of the polymer, the release of the rifampicin from the microparticles decreased. The findings showed that rifampicin release followed zero-order kinetics and that drug release from these particles is frequently influenced by diffusion. The electronic structure and characteristics of the conjugated polymers (sodium alginate/Chitosan) were examined using density functional theory (DFT) and PM3 calculations with Gaussian 9, using the B3LYP, and electronic structure calculations using 6-311 G (d,p). The HOMO and LUMO energy levels are determined as the HOMO's maximum and the LUMO's minimum, respectively.Communicated by Ramaswamy H. Sarma.

A dispersion-corrected DFT calculation on encapsulation of favipiravir drug used as antiviral against COVID-19 into carbon-, boron-, and aluminum-nitride nanotubes for optimal drug delivery systems combined with molecular docking simulations

Favipiravir (FAV) (6-fluoro-3-oxo-3,4-dihydropyrazine-2-carboxamide) is one of the most effective antiviral drugs which is cited for action against RNA-viral infections of COVID-19. In this study, density functional theory (DFT) calculations were used to investigate three nanotubes (NTs) with FAV drug as delivery systems. The encapsulated systems (ESs) consist of FAV drug inside carbon-carbon, aluminum nitride, and boron nitride. At B3LYP-D/6-31G(d,p) and CPCM/B3LYP-D/6-31G(d,p), the optimization of NTs, FAV, and its tautomeric forms and six ESs was investigated in gas and water environments. Five tautomeric forms of FAV were investigated, two keto forms (K1 and K2) and three enol forms (E1, E2, and E3). The results revealed that E3 and K2 isomeric forms represented the most stable structures in both media; thus, these two forms were encapsulated into the NTs. The stability and the synthesis feasibility of NTs have been proven by calculating their interaction energies. Non-covalent interactions (NCIs) were investigated in the ESs to show the type of NCI with the molecular voids. The binding energies, thermochemical parameters, and recovery times were investigated to understand the mechanism of FAV encapsulation and release. The encapsulated AlNNT systems are more favorable than those of BNNTs and CNTs in gas and aqueous environments with much higher binding energies. The quantum theory of atoms in molecules (QTAIM) and recovery time analysis revealed the easier releasing of E3 from AlNNT over K2 form. Based on molecular docking simulations, we found that E3 and K2 FAV forms showed a high level of resistance to SARS-CoV-6M3M/6LU7/6W9C proteases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11224-023-02182-4.

Application of DFT Calculations in Designing Polymer-Based Drug Delivery Systems: An Overview

Drug delivery systems transfer medications to target locations throughout the body. These systems are often made up of biodegradable and bioabsorbable polymers acting as delivery components. The introduction of density functional theory (DFT) has tremendously aided the application of computational material science in the design and development of drug delivery materials. The use of DFT and other computational approaches avoids time-consuming empirical processes. Therefore, this review explored how the DFT computation may be utilized to explain some of the features of polymer-based drug delivery systems. First, we went through the key aspects of DFT and provided some context. Then we looked at the essential characteristics of a polymer-based drug delivery system that DFT simulations could predict. We observed that the Gaussian software had been extensively employed by researchers, particularly with the B3LYP functional and 6-31G(d, p) basic sets for polymer-based drug delivery systems. However, to give researchers a choice of basis set for modelling complicated organic systems, such as polymer–drug complexes, we then offered possible resources and presented the future trend.

Theoretical evaluation of poly(amidoamine) dendrimers with different peripheral groups as a purinethol drug delivery system in aqueous medium

In this work, density functional theory calculations were used to study the association of PUR with amine- and acetyl-terminated PAMAM dendrimers considering implicit solvent effect at neutral and low pH conditions. Frontier molecular orbitals' analysis indicates that the electronic properties of dendrimers are extremely sensitive to the presence of PUR molecule at both neutral and low pH conditions. Encapsulation of PUR molecule into the both amine- and acetyl-terminated PAMAM dendrimers leads to a Gibbs free energy of (ΔG) - 20.25 kcal.mol^-1 at physiological pH. The corresponding ΔG values reduce to the - 1.45 and - 0.91 kcal.mol^-1 at low pH, indicating that the drug molecule is released easily at low pH. The calculated recovery times for amine- (3.87 ×10² and 3.87 ×10², at neutral and low pH, respectively) and acetyl-terminated (5.34 ×10¹⁰ and 1.81 ×10^-1, at neutral and low pH, respectively) dendrimers suggest that acetylation can improve the release pattern of drug molecule.

Exploration of phosphorene as doxorubicin nanocarrier: An atomistic view from DFT calculations and MD simulations

Potential capability of phosphorene nanosheet (PNS) as doxorubicin (DOX) nanocarrier was investigated using density functional theory (DFT) method and molecular dynamics (MD) simulations. Both DFT calculations and MD simulations revealed that the DOX molecule is adsorbed horizontally onto the PNS surface with the nearest interaction distance of 2.5 Å. The binding energy of DOX is predicted to be about - 49.5 kcal.mol^-1, based on the DFT calculations. After DOX adsorption, the E_g value of PNS remains almost constant in both gas and solvent phases. The dynamical behavior of PNS-DOX was studied at T = 298, 310, and 326 K that reminiscent of room temperature, body temperature, and temperature of tumor after exposure to 808 nm laser radiation, respectively. The diffusion coefficient values of DOX molecule are proportional to temperature. We found that PNS can hold a high amount of DOX on both sides of its surface (66% in weight). MD simulations showed that the dynamical behavior of simulated systems are not affected by pH variances.

Application of Dendrimers in Anticancer Diagnostics and Therapy

The application of dendrimeric constructs in medical diagnostics and therapeutics is increasing. Dendrimers have attracted attention due to their compact, spherical three-dimensional structures with surfaces that can be modified by the attachment of various drugs, hydrophilic or hydrophobic groups, or reporter molecules. In the literature, many modified dendrimer systems with various applications have been reported, including drug and gene delivery systems, biosensors, bioimaging contrast agents, tissue engineering, and therapeutic agents. Dendrimers are used for the delivery of macromolecules, miRNAs, siRNAs, and many other various biomedical applications, and they are ideal carriers for bioactive molecules. In addition, the conjugation of dendrimers with antibodies, proteins, and peptides allows for the design of vaccines with highly specific and predictable properties, and the role of dendrimers as carrier systems for vaccine antigens is increasing. In this work, we will focus on a review of the use of dendrimers in cancer diagnostics and therapy. Dendrimer-based nanosystems for drug delivery are commonly based on polyamidoamine dendrimers (PAMAM) that can be modified with drugs and contrast agents. Moreover, dendrimers can be successfully used as conjugates that deliver several substances simultaneously. The potential to develop dendrimers with multifunctional abilities has served as an impetus for the design of new molecular platforms for medical diagnostics and therapeutics.

Drug-dendrimer complexes and conjugates: Detailed furtherance through theory and experiments

Dendritic nanovectors-based drug delivery has gained significant attention in the past couple of decades. Dendrimers play a crucial role in deciding the solubility of sparingly soluble drug molecules and help in improving pharmacokinetics. A few important steps in drug delivery through dendrimers, such as drug encapsulation, formulation, and target-specific delivery, play an important role in deciding the fate of a drug molecule. It is also of prime importance to understand the interactions between a drug molecule and dendrimers at atomistic levels to decode the mechanism of action of drug-dendrimer complexes and their reliability in terms of drug delivery. Colossal progress in current experimental and computational approaches in the field has resulted in a vast amount of data that needs to be curated to be further implemented efficiently. Improved computational power has led to greater accuracy and prompt predictions of properties of drug-dendrimer complexes and their mechanism of action. The current review encapsulates the pioneering work in the field, experimental achievements in terms of drug delivery, and newer computational techniques employed in the advancement of the field.

Correlating the charge transfer efficiency of metallic sulfa-isatins to design efficient NLO materials with better drug designs

The present study presents synthesis, characterization and first principle studies on metal chelates, (1-12), of sulfonamide-isatin reacted ligands (S¹-S³). All the products were evaluated by various physical and spectral (UV, IR, NMR, MS) means. The octahedral geometry for Co⁺², Ni⁺² and Zn⁺², while square planner geometry for Cu⁺² chelates were confirmed by their spectroscopic and magnetic data. Their physical chemistry investigation show the ability of aromatic rings to stabilize sulfonamide rings across NH-π interactions at their optimized geometries. The nonlinear optical response for all the compounds disclosed that the z-axis has the most contributions. An efficient electron injection and hole studies for Au and Al electrodes having the energies of - 0.1-3.1 and 0.0-11.8 eV respectively were noted. Their bioactive character was shown by global reactivity calculated from FMO energy gaps. The enzyme inhibitory results were found to be 45-61% and IC₅₀ = 102-122 µL, for compound (4), (10), (8), (5) and (12) against the amylase, protease, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) respectively The antibacterial findings showed significant action having 11-17 mm for (2), (7) and (10) for bacterial species, Escherichia coli and Micrococcus luteus. The DPPH and ferric reducing power assay was used to evaluate the antioxidant capacity with 49.0 ± 0.09-66.2 ± 0.08% and IC₅₀ = 102.3-122.4 µL range. In comparison to ligands, the results showed that all metal chelates had higher bioactivity. The chelation was the primary cause of their increased bioactivity. These findings suggested that such metal-based compounds might be used as antimicrobial, and antioxidant options in future to cope drug resistance.