Molecular Dynamics Insight into the Urea Effect on Tretinoin Encapsulation into Carbon Nanotube

Maryam Ghadamgahi,Davood Ajloo

doi:10.5935/0103-5053.20140242

Abstract

Molecular dynamics simulations at 270 and 310 K rationalized the effect of urea, temperature and the size of the carbon nanotube, on the insertion of Tretinoin into nanotubes with chirality (10, 7) and (8, 5). Concentrations of 0.9 mmol L−1 and 2 mol L−1 of urea are studied, that are less and more than the normal range of blood urea content, respectively. Results show that encapsulation of Tretinoin could be ascribed to the flow of the waters via hydrophilic and van der Waals interactions and diameter of the nanotube. Heat capacity, diffusion coefficient, free energy and contact coefficient change with the temperature and urea. Tretinoin molecule locates inside the nanotube due to the partial π-π interactions between oxygen atom of Tretinoin and the conjugated aromatic rings of nanotube. Finally, high concentration of urea causes the striking phenomenon of inducing the drying of nanotube that result in urea wires and instability of encapsulation.

Highlights

Reducing toxicity of therapeutic materials is the main aim of developing drug-delivery systems that is achieved using carbon nanotubes (CNTs).1,2 The intense interest in CNTs is due to the capability of absorbing or conjugating with a wide variety of medicinal molecules.3 They have unique chemical and physical properties and applications from high strength and low weight nanocomposite materials to electronic devices.4 Drug molecule penetrates through the cancer cell by CNT to treat diseases and thereby potentially reducing the drug side effects by preserving the noncancerous tissues of the patients.5 This is a characteristic ofThe most common form of human cancer, skin cancer, estimates to occur over two million new cases annually.9 The increase of annual rates of skin cancer each year represents public concern
The results revealed that the drug molecule stays inside the CNT cavity throughout the simulation time at 310 K in water, and that this was possibly due to lone pair of oxygen atoms as donor atoms that can transfer electron to acceptor atoms σ* or π* in carbon nanotube, that is the most important common interaction in the nanotube-Tretinoin composite, as detected previously
Our results show that the proper diameters of the CNT and water flow are the important factors for the drug encapsulation

Summary

Introduction

Reducing toxicity of therapeutic materials is the main aim of developing drug-delivery systems that is achieved using carbon nanotubes (CNTs).1,2 The intense interest in CNTs is due to the capability of absorbing or conjugating with a wide variety of medicinal molecules.3 They have unique chemical and physical properties and applications from high strength and low weight nanocomposite materials to electronic devices.4 Drug molecule penetrates through the cancer cell by CNT to treat diseases and thereby potentially reducing the drug side effects by preserving the noncancerous tissues of the patients.5 This is a characteristic ofThe most common form of human cancer, skin cancer, estimates to occur over two million new cases annually.9 The increase of annual rates of skin cancer each year represents public concern. Interaction energy between the drug molecule and CNT in water and urea are analyzed and discussed at and 310 K using molecular dynamics (MD) simulation.

Results

Conclusion