Experimental and Computational Investigations of Carboplatin Supramolecular Complexes

Sherif Ashraf Fahmy; Fortuna Ponte; Emilia Sicilia; Hassan Mohamed El-Said Azzazy

doi:10.1021/acsomega.0c05168

Experimental and Computational Investigations of Carboplatin Supramolecular Complexes

ACS Omega. 2020 Nov 25;5(48):31456-31466. doi: 10.1021/acsomega.0c05168. eCollection 2020 Dec 8.

Authors

Sherif Ashraf Fahmy¹, Fortuna Ponte², Emilia Sicilia², Hassan Mohamed El-Said Azzazy¹

Affiliations

¹ Department of Chemistry, School of Sciences & Engineering, The American University in Cairo, AUC Avenue, P.O. Box 74, New Cairo 11835, Egypt.
² Department of Chemistry and Chemical Technologies, University of Calabria, Arcavacata di Rende 87036, Italy.

Abstract

Supramolecular systems (macromolecules), such as calix[n]arenes (SCn), cyclodextrins (CDs), and cucurbiturils (CBs), are promising vehicles for anticancer drugs. In this work, guest-host complexes of carboplatin, a second-generation platinum-based anticancer drug, and p-4-sulfocalix[n]arenes (n = 4 and 6; PS4 and PS6, respectively) were prepared and studied using ¹H NMR, UV, Job's plot analysis, HPLC, and density-functional theory calculations. The experimental and the computational studies suggest the formation of 1:1 complexes between carboplatin and each of PS4 and PS6. The stability constants of the formed complexes were estimated to be 5.3 × 10⁴ M^-1 and 9.8 × 10⁴ M^-1, which correspond to free energy of complexation of -6.40 and -6.81 kcal mol^-1, in the case of PS4 and PS6, respectively. The interaction free energy depends on the different inclusion modes of carboplatin in the host cavities. UV-vis findings and atoms in molecules analysis showed that hydrogen bond interactions stabilize the host-guest complexes without the full inclusion in the host cavity. The in vitro anticancer study revealed that both complexes exhibited stronger anticancer activities against breast adenocarcinoma cells (MCF-7) and lung cancer cells (A-549) compared to free carboplatin, preluding to their potential use in cancer therapy.