Polymeric nanoparticles have emerged as efficient carriers for anticancer drug delivery because they can improve the solubility of hydrophobic drugs and also can increase the bio-distribution of drugs throughout the bloodstream. In this work, a computational study is performed on a set of new pH-sensitive polymer-drug compounds based on an intelligent polymer called poly(β-malic acid) (PMLA). The molecular dynamics (MD) simulation is used to explore the adsorption and dynamic properties of PMLA-doxorubicin (PMLA-DOX) interaction with the graphene oxide (GOX) surface in acidic and neutral environments. The PMLA is bonded to DOX through an amide bond (PMLA-ami-DOX) and a hydrazone bond (PMLA-hz-DOX) and their adsorption behavior is compared with free DOX. Our results confirm that the polymer-drug prodrug shows unique properties. Analysis of the adsorption behavior reveals that this process is spontaneous and the most stable complex with a binding energy of -1210.262 kJ mol-1 is the GOX/PMLA-hz-DOX complex at normal pH. On the other hand, this system has a great sensitivity to pH so that in an acidic environment, its interaction with GOX became weaker while such behavior is not observed for the PMLA-ami-DOX complex. The results obtained from this study provide accurate information about the interaction of the polymer-drug compounds and nanocarriers at the atomic level, which can be useful in the design of smart drug delivery systems.
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