Comparative DFT Study of 5-Fluorouracil Adsorption on Silica and Graphene for Bio-Medical Applications

Aims: The administration of antitumor 5-Fluorouracil (5-FU) into the human body is generally accomplished via a central venous catheter that is prone to degradation when it comes in contact with bodily fluids or aggressive drugs such as 5-Fu. Therefore, degradation could be reduced by applying protective coatings onto the internal and/or external surfaces of the catheters. Objective: Graphene and silica materials could be promising coating materials because of their low reactivity and antimicrobial properties. The mechanisms of interaction between the carrier and the drug are based on surface chemistry related phenomena. Understanding the physicochemical features of the surfaces is a fundamental step to describe and predict the strength of these interactions and may result in controlled adsorption and release processes. Methods: Computational DFT methods can provide an important aspect by providing atomistic details of the drug adsorbed on the surfaces through molecular modeling. Results: DFT calculations of the binding energy, charge exchange and orbital population of 5-FU adsorbed on graphene and silica materials confirmed weak interactions between the drug and the solid surfaces that could favor desorption during the drug delivery. Graphene and silica surfaces do not react with the 5-FU molecule behaving as inert materials and the drug does not suffer from degradation nor alter its structure during adsorption on both the materials. Conclusion: These characteristics, in addition to biocompatibility and antimicrobial properties, suggest that graphene and silica could be used as promising internal/external coating materials for biomedical applications.