Purpose: Prednisolone, a synthetic corticosteroid drug, is extensively utilized to treat inflammatory diseases and regulates metabolism and the immune system in cancer treatment. However, these drugs are toxic and cause severe side effects if administrated for long durations and in large doses. This work intends to study the atomistic interactions of popular polymeric carrier like PLGA with the drug and thereby provide insights into achieving better loading and a sustained release. Methods: Molecular dynamics (MD) simulations of prednisolone (drug) encapsulated in Poly Lactic-co-Glycolic acid (PLGA) are performed in this study. Grand Canonical Monte Carlo (GCMC) simulations with MD simulations are conducted to determine the water penetration in PLGA polymer and polymer stability in water. The investigations from this study encompasses structural and dynamical parameters, including the end-to-end distance, radius of gyration of polymer chains, interaction energy, and diffusion coefficient of the drug. Results: The polymer-drug interactions are studied and identified from the simulation data of PLGA(75:25) and PLGA(50:50) polymers with prednisolone in an aqueous medium for optimal drug carrying capacity and effective drug release. Also, the polymeric systems of PLGA(75:25) and PLGA(50:50) are analyzed with the water penetrant loading using the Grand Canonical Monte Carlo (GCMC) and MD simulations. Water loading analysis revealed that PLGA(75:25) has the highest swelling compared to PLGA(50:50). Conclusion: This study highlights the characteristics and critical parameters for developing an optimal drug delivery system by investigating polymer-drug interactions, drug encapsulation, and water uptake in polymers using MD and GCMC simulations.

One of the major constituents of heavy oil is asphaltenes. They are responsible for numerous problems in petroleum downstream and upstream processes, such as catalyst deactivation in heavy oil processing and blocking pipes while transporting crude oil. Probing the efficiency of new nonhazardous solvents in separating asphaltenes from crude oil is key to avoid conventional volatile and hazardous solvents by replacing these conventional solvents with new ones. In this work, we have investigated the efficiency of ionic liquids to separate asphaltenes from organic solvents (such as toluene and hexane) using molecular dynamics simulations. Triethylammonium-dihydrogen-phosphate and triethylammonium acetate ionic liquids are considered in this work. Various structural and dynamical properties are calculated, such as radial distribution function, end-to-end distance, trajectory density contour, and diffusivity of asphaltene in the ionic liquid-organic solvent mixture. Our results explain the role of anions, i.e., dihydrogen-phosphate and acetate ions, in separating asphaltene from toluene and hexane. Our study provides an important revelation about the dominant role played by the IL anion in intermolecular interactions which depends on the type of solvent (i.e., toluene or hexane) in which the asphaltene is present. The anion induces enhanced aggregation in the asphaltene-hexane mixture compared to the asphaltene-toluene mixture. The molecular insights obtained within this study on the role played by ionic liquid anion in asphaltene separation are key for the preparation of new ionic liquids for asphaltene precipitation applications.

Doxorubicin is cytotoxic anthracycline antibiotic drug used in cancer treatment. The drug's efficacy in various kinds of cancer made its usage dominant for treating cancers. In this study, we determined the solubility of the doxorubicin in three different polymers, i.e., poly (N-isopropyl acrylamide), polyethylene glycol, and polyvinyl pyrrolidone, to increase the doxorubicin's drug efficacy on the targeted tumor site. We investigated the doxorubicin-polymer interactions with carbon-nanotube in the aqueous environment for the targeted delivery application using classical molecular dynamics simulations. An in-depth atomistic insight into polymer interaction with the drug/carbon-nanotube/water is obtained within the study. We have critically analyzed various properties such as interaction energy, hydrogen bonds between polymer-drug and polymer-water, the diffusion coefficient of the drug, end-to-end distance, radius of gyration of the polymer chains, and finally, drug density contours for different drug to polymer ratios. Our results explain the selection of effective monomer chain length of polymer and the suitability of the polymer carrier with doxorubicin.