High drug carrying efficiency of boron-doped Triazine based covalent organic framework toward anti-cancer tegafur; a theoretical perspective

The therapeutic potential of Triazines-based six-membered ring covalent organic framework (COF) and respective boron doped derivative toward anticancer drug i.e., Tegafur (TG) is evaluated using the first principles DFT calculations. The geometric, energetic, and electronic properties of TG@Triazine and TG@TriazineB2 are computed to explore and compare the efficacy of selected COFs as drug carrier systems. The strength of the adsorption of tegafur onto the triazine-COFs is illustrated through the counterpoise corrected adsorption energies (Ecp). The computed Ecp of TG@Triazine and TG@TriazineB2 are-21.81 and-25.57 kcal/mol, which illustrate the physisorption of the drug on adsorbent. The nature of interactions i.e., physisorption between tegafur and Triazine COFs is further illustrated via the noncovalent interaction index (NCI) plot and quantum theory of atom in molecules (QTAIM), which illustrated that the weak dispersion forces are present between the drug and COF adsorbents. In comparison, the adsorption strength is significantly high in boronated triazineB2 COF. The electronic properties, including HOMO-LUMO analysis and NBO charge transfer analysis, reveal the significant variation in the electronic behavior of triazine COF, upon doping with boron, the Eg (HOMO-LUMO gap) of pristine Triazine (4.15 eV) reduced to 0.49 eV in TriazineB2 analogue. This significant decrease in the Eg of Triazine on boron doping illustrates the shifting of the semiconducting behavior of pristine Triazine to the metallic nature of TriazineB2, thus the electron transportation becomes double the magnitude (0.018 |e|) on interaction with tegafur drug as compared to 0.07 |e| in TG@Triazine. Finally, the recovery time is computed to illustrate the time taken by the drug in detaching at the active site. With this study, it is confirmed that the triazine-COF can be a significant drug carrier, however, the doping of boron further enhances the therapeutic potential of the adsorbent.