Department of Chemistry, Faculty of Science, Shahr-E-Qods Branch, Islamic Azad University, Tehran, Iran.
Department of Chemistry, Doroud Branch, Islamic Azad University, P.O. Box: 133. , Doroud, Iran.
J Mol Model. 2021 Aug 17;27(9):251. doi: 10.1007/s00894-021-04865-3.
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 (E) is equal to the lowest value 65.24 a.u.
纳米氧化石墨烯的结构因其亲水性、特殊表面、生物相容性以及能够高负载亲水和疏水药物等特殊性质，在药物释放中引起了特别关注。在这项研究中，模拟和优化了纳米石墨烯的结构，然后是纳米氧化石墨烯（NGO），用于在水介质中负载喜树碱（CA）抗癌药物，并研究了实现药物最大负载效率的最佳条件。由于药物的结构，存在两种形式，一种是内酯环形式，另一种是羧酸盐形式。如果内酯环形式占主导地位，药物的有效性就会增加。这取决于环境的 pH 值。计算的热力学和结构结果表明，纳米氧化石墨烯保持了药物关于纳米氧化石墨烯的溶解度及其内酯环状态。为了提高药物的有效性，必须保持药物结构中的内酯环形式。在水介质中使用叶酸作为中间体能保持药物结构中的内酯环形式，从而提高其有效性。结果表明，药物结构中环的存在及其与叶酸到纳米氧化石墨烯的介导物的结合是酮式互变异构体的稳定因素。振动频率的计算表明，叶酸中间体能降低羟基（OH）的振动频率，使其吸收能（E）等于最低值 65.24 a.u.
