Potentiality of carbon nanotube to encapsulate some alkylating agent anticancer drugs: a molecular simulation study

Pharmaceuticals in the environment: A strategy for prioritizing molecules of environmental concern

The presence of drugs in the environment is a growing global concern, and selecting molecules for study is challenging. We propose a logical and integrative strategy to prioritize molecules of concern by predicting potential masses entering the environment, followed by a prioritization step. Our strategy was applied to antineoplastics with limited biodegradability, narrow therapeutic-to-dose margins, and significant ecotoxicological effects. As a case study, we used data from 2022 for cities in the Alto Tietê watershed (São Paulo, Brazil), which hosts ∼22 million people. The predicted mass (PM) of antineoplastics potentially introduced into water bodies (807 kg) was calculated using cities sales data (4609 kg), sanitation and pharmacokinetic data, and wastewater treatment plant (WWTP) removal rates obtained from EPISuite™. The prioritization involved molecules accounting for 99% of the PM, using ToxPi™ software to create a Prioritization Index (PI), rose plots, and dendrograms for risk profile evaluation. Without PM data, prioritization relies solely on intrinsic molecular characteristics. Prioritization parameters were categorized into four: Physicochemical Properties (water solubility, KOW, KOC), Environmental Fate (WWTP removal, half-lives), Effects (BCF, ecotoxicity, mutagenicity, chronic toxicity, carcinogenicity, endocrine disruption potential), and Exposure (PM). Different weights were applied to Exposure to ensure higher PM antineoplastics were prioritized without overshadowing other parameters. Obtaining a priority set with the contribution of all parameters was possible. The prioritized antineoplastics were Paclitaxel, Capecitabine, Pemetrexed, Gemcitabine, Cisplatin, 5-Fluorouracil, Mitotane, Imatinib, Cyclophosphamide, and Carboplatin. This strategy can be applied to different contexts to generate appropriate prioritization sets.

Effect of functionalization on the adsorption performance of carbon nanotube as a drug delivery system for imatinib: molecular simulation study

In this study, efficiency of functionalized carbon nanotube as a potential delivery system for imatinib anti-cancer drug was investigated. Accordingly, carboxyl and hydroxyl functionalized carbon nanotube were inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, possible interactions of imatinib with pure and functionalized carbon nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that pure and functionalized carbon nanotubes can act as imatinib drug adsorbents in gas phase. However, results of association free energy calculations in aqueous solution indicated that only carboxyl and hydroxyl functionalized carbon nanotubes could interact with imatinib. Monte Carlo simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Computed solvation free energies in water showed that the interactions with functionalized carbon nanotubes significantly enhance the solubility of imatinib, which could improve its in vivo bioavailability.

Interaction of sulfasalazine with outer surface of boron-nitride nanotube as a drug carrier in aqueous solution: insights from quantum mechanics and Monte Carlo simulation

The improvement of the solubility of sulfasalazine in physiological media was the major aim of this study. Accordingly, BNNT inspected as a notable candidate for the carriage of this drug in aqueous media. For this purpose, four possible interactions of two tautomer of sulfasalazine with (9,0) boron-nitride nanotube were considered in aqueous media. The compounds were optimized in gas phase using density functional calculations. Solvation free energies and association free energies of the optimized structures were then studied by Monte Carlo simulation and perturbation method in water environment. Outcomes of quantum mechanical calculations presented that interaction of keto form of sulfasalazine produce the most stable complexes with boron-nitride nanotube in gas phase. Simulation results revealed that electrostatic interactions play a vital role in the intermolecular interaction energies after binding of drug and nanotube in aqueous solution. Results of association free energy calculations indicated that complexes of both two sulfasalazine tautomers (keto and enol) and nanotube were stable in solution. Computed solvation free energies in water showed that the interaction with boron-nitride nanotube significantly improved the solubility of sulfasalazine, which could improve its in vivo bioavailability.

Assessing the impact of antineoplastic drugs in the aquatic environment: State of the art and future perspective for freshwater organisms

Since the late 70s, the continuous pharmaceuticals` input into the environment has raised concerns regarding the eventual risk posed by such compounds to human and environmental health. A major group of pharmaceuticals in terms of environmental impact are the antineoplastic agents (AAs). Herein, we followed a systematic review method to retrieve antineoplastic agents (AAs') ecotoxicological information regarding freshwater species. In this analysis, data from diverse taxonomic groups, from microorganisms to vertebrate species, looked at different levels of biological organization, including cell lines. Furthermore, this review gathers ecotoxicological parameters (EC₅₀ and LC₅₀) for imatinib (IM), cisplatin (CisPt), and 5-fluorouracil (5-FU) in species sensitivity distribution (SSD) curves and estimates the hazard concentration (HC₅) considering the protection of 95% of the ecological community. Lastly, we suggest how we can improve AAs' Environmental Risk Assessment (ERA), considering potential adoptable toxicity endpoints, test duration, AAs metabolites testing, and AAs mixture exposure.