Graphene-based hybrid composites for cancer diagnostic and therapy.

The application of graphene-based nanocomposites for therapeutic and diagnostic reasons has advanced considerably in recent years due to advancements in the synthesis and design of graphene-based nanocomposites, giving rise to a new field of nano-cancer diagnosis and treatment. Nano-graphene is being utilized more often in the field of cancer therapy, where it is employed in conjunction with diagnostics and treatment to address the complex clinical obstacles and problems associated with this life-threatening illness. When compared to other nanomaterials, graphene derivatives stand out due to their remarkable structural, mechanical, electrical, optical, and thermal capabilities. The high specific surface area of these materials makes them useful as carriers in controlled release systems that respond to external stimuli; these compounds include drugs and biomolecules like nucleic acid sequences (DNA and RNA). Furthermore, the presence of distinctive sheet-like nanostructures and the capacity for photothermal conversion have rendered graphene-based nanocomposites highly favorable for optical therapeutic applications, including photothermal treatment (PTT), photodynamic therapy (PDT), and theranostics. This review highlights the current state and benefits of using graphene-based nanocomposites in cancer diagnosis and therapy and discusses the obstacles and prospects of their future development. Then we focus on graphene-based nanocomposites applications in cancer treatment, including smart drug delivery systems, PTT, and PDT. Lastly, the biocompatibility of graphene-based nanocomposites is also discussed to provide a unique overview of the topic.

Effects of L-ascorbic acid (C6H8O6: Vit-C) on collagen amino acids: DFT study.

Vitamin C plays a very important role in the repair of connective tissue, especially for sports whose training causes the most damage to this tissue. Therefore, many people believe that L-ascorbic acid (C6H8O6: vitamin C) reduces the recovery time between sports exercises. The most abundant form of structural protein in the body is collagen. Collagen is characterized by a high concentration of the three amino acids glycine (Gly), proline (Pro), and hydroxyproline (Hyp), which creates its characteristic triple helix structure. Therefore, in this study, the effect of vitamin C presence on the sequence, interaction, and orientation of amino acids for collagen formation is investigated using computational simulation. This study aimed to investigate the mechanism of action of vitamin C in terms of thermodynamics and structure of the reaction. The calculations are performed using density function theory (DFT) by the base set of B3LYP/6-311++G (p,d). The results show that the presence of vitamin C is effective in the formation of collagen protein for this interaction and the mechanism of amino acid sequence (Gly-Hyp-Pro) is better in the formation of collagen protein in the presence of vitamin C. The presence of Vit-C in the formation and direction of hydroxyproline (Hyp) causes its separation from the prolyl 5-hydroxylase enzyme. In the absence of vitamin C, the reaction stops at this stage and proline cannot be converted into hydroxyproline. The computational data shows vitamin C prevents unwanted interactions and directs amino acid reactions to repair connective tissue (collagen). Therefore, vitamin C acts as a cofactor in the Prolyl 5-Hydroxylase enzyme and causes it to convert proline to hydroxyl.

DFT study on the removal of polyacrylamide by titanium dioxide nanoparticles/polyacrylonitrile (rTiO2@PAC) composite in aqueous solutions.

Due to its high solubility in water, polyacrylamide is one of the most widely used materials for removing environmental pollutants by coagulation and flocculation. It is worth noting that the excess amount of this polymer in the wastewater is considered a secondary pollutant, which causes the blocking of the membranes and filters used in the treatment plant. Polyacrylonitrile (PAN) is one of the practical polymers used to remove this pollutant, and its performance can be increased by using physical modification and hydrolysis of this polymer (poly-acrylic carboxylate (PAC)). This study evaluated and investigated structural and thermodynamic parameters of hydrolyzed polyacrylonitrile polymer containing rutile-titanium dioxide (rTiO2) nanoparticles, and conversion of polyacrylamide to other products by computational methods. The obtained data show that titanium dioxide nanoparticles reduce the energy gap (Eg = 8.88 eV) and as a result increase the polarity and conductivity of the nanocomposite (rTiO2@PAC). Gibbs free energy in the polyacrylamide conversion stage is equal to - 278.63 kJ mol -1. This decrease indicates the tendency of nanocomposite to transform the pollutant and reduce its blocking in the wastewater environment, and the obtained results show a good agreement with the experimental data.

Simulation and computational study of graphene oxide nano-carriers, absorption, and release of the anticancer drug of camptothecin.

The structure of nano-graphene oxide has attracted special attention in drug release due to its special properties such as hydrophilicity, special surface, biocompatibility, and the possibility of high loading of hydrophilic and hydrophobic drugs. In this study, after simulating and optimizing the structure of nano-graphene and then nano-graphene oxide (NGO), it was used to load the anti-cancer drug of camptothecin (CA) in an aqueous medium, and the optimal conditions for achieving maximum loading efficiency of the drug were investigated. Due to the structure of the drug, there are two forms, one form of lactone ring and the other carboxylate. If the lactone ring form is predominant, the effectiveness of the drug is increased. This depends on pH of the environment. The calculated thermodynamic and structural results show that the solubility of the drug about nano-graphene and its lactone ring state is maintained by using nano-graphene oxide. To increase the effectiveness of the drug, the lactone ring form must be maintained in the drug structure. The use of folic acid as an intermediate in the aqueous medium preserves the lactone form in the drug structure and increases its effectiveness. The results show that the presence of the ring in the drug structure and its binding to the mediator of folic acid to nano-graphene oxide is a stabilizing factor of keto tautomer. The calculation of vibrational frequencies shows that the presence of folic acid intermediate reduces the vibrational frequency of the hydroxyl group (OH) so that its absorption energy (Ead) is equal to the lowest value 65.24 a.u.

Phytoremediation and absorption isotherms of heavy metal ions by Convolvulus tricolor (CTC).

In recent years, use of plants for remediation of contaminated soils, especially removal of heavy metals, is considered. The current study tends to investigate the removal of lead and nickel ions by the Convolvulus tricolor (CTC), was grown for 30 days in different concentrations of lead and nickel ions. Then concentration of them in soil and different organs of the plant was measured by atomic absorption spectrometry. The highest absorbed of them occurred in concentration 0.001N, which highest Pb(2+) accumulation is in the aerial parts of the plant: leaf > stem > root and for Ni(2)+: root > stem > leaf. No ion was observed into the flowers and nickel ion absorption is more of lead ion in different plant organs of CTC. The experimental isotherm data were investigated using isotherms of Langmuir, Freundlich, BET, Temkin and Dubinin-Radushkevich (DRK). The correlation coefficient for all of them is calculated that show the best correlation coefficient for Ni(2+) adsorption is obtained BET model, whereas for Pb(2+) adsorption in root is Freundlich model but for its leaf and stem is BET model. The results show, CTC is suitable for Pb(2+) and Ni(2+) and this technique is in-situ method, simple, and low cost.

Using of TiN-nanotubes and Cu-nanoparticles for conversion of CO2 to hydrocarbon fuels.

In this study, conversion of CO2 and H2O to CH3OH or CH4 on Cu-nanoparticles in TiN- nanotubes was optimized by density functional theory (DFT) methods. DFT optimized the intermediates and transient states using the GAMESS program package, but the structures, total energy, and thermodynamic properties were calculated by semi-empirical methods using ZINDO/1 at room temperature. The results show a sensitivity enhancement in resistance and capacitance when CO2 and H2O are converted to CH3OH and other products. TiN-nanotubes use photo-catalytic reactivity for the reduction of CO2 and H2O to form CH3OH or CH4 at 298 K. The endohedral location of interaction of these reactants in TiN-nanotubes with Cu-nanoparticles was investigated. Calculations show that these processes were endothermic, thus the reactions need solar or other energies in the presence of visible light to progress favorably.